Dissertations / Theses on the topic 'Mine rehabilitation'

Thesis (MScFor)--Stellenbosch University, 2002.
ENGLISH ABSTRACT: Namaqualand has a very unusual diversity of plant life, with many endemic plant species. The fundamental question of this thesis is how this system, damaged by strip-mining activities, can be rehabilitated. The aim was to base the rehabilitation methods on ecological processes. In order to answer this question an overview of the relevant literature was needed in order to identify possible research needs and also to evaluate the work that has been done in the field of strip-mine rehabilitation in arid areas. An understanding of community and ecosystem dynamics would help to establish aims and methods for site-specific rehabilitation. In Namaqualand, South Africa, there is also a need for experimentation to establish which of the many factors is most limiting to long-term ecosystem recovery. It is important to have a good knowledge of the successional processes and disturbance history of the land which needs to be rehabilitated. The vegetation on unmined areas and mined areas of different ages and treatments after mining, were sampled. It was shown that some areas could be expected to show a large degree of recovery in the space of a few years, whilst others would show little or no recovery over a period of decades. It is important to recognise rehabilitation as a gradual process that takes place at different rates in different areas and in different years. The planting of Atriplex nummularia and sowing of Atriplex semibaccata did not facilitate the return of indigenous, perennial species, but rather seem to inhibit their return. In view of the importance of topsoil in terms of the fertility of the soil and the seed bank present in the topsoil, the influence of topsoil removal and stockpiling due to strip-mining activities were tested. The soil fertility was tested by means of radish bioassays and soil laboratory analysis, whilst species diversity and richness were tested with seedling emergence trials. As expected a higher plant species diversity was found on the unmined soils and radishes grew larger on these soils. The topsoil deteriorated in terms of plant species richness, diversity and soil fertility whilst it was stockpiled. Direct replacement of topsoil would ensure a planting medium closer to the pre-disturbance level that could lead to fairly rapid and successful recolonization of the mined area. Successful plant recruitment also depends on the microsites to which seeds are dispersed. The effect that different microsites had on seed germination, seedling growth and survival was tested. It was found that micro catchments always yielded the highest numbers. The establishment and survival of seedlings in the other microsite types (under single shrubs, under clumped shrubs and in the open) varied, depending on the amount of rainfall received in the particular year. Lastly, I experimented with the translocation of three local, indigenous, succulent plant species. These plants were transplanted either in clumps of three together or alone, since I hypothesized that planting them together would facilitate their survival. However, it was found that it depended largely on the morphology of the plant and the amount of rainfall received in a particular year, whether these plants will compete with each other for limiting resources or facilitate each other's survival. The thesis contributes to the understanding of vegetation dynamics in the Succulent Karoo after strip-mining has taken place. Guidelines are provided based on ecological processes, for strip-mine rehabilitation in the Succulent Karoo.
AFRIKAANSE OPSOMMING: Namakwaland is bekend vir sy ongewone diversiteit van plante, met baie endemiese spesies. Die fundamentele vraag wat deur hierdie tesis gevra word is hoe hierdie sisteem, wat beskadig is deur oppervlak mynbou, gerehabiliteer kan word. Die doel is om die rehabilitasie metodes te baseer op ekologiese prosesse. 'n Oorsig van die relevante literatuur was nodig om moontlike areas van verdere navorsing te identifiseer en ook die navorsing wat reeds gedoen is oor rehabilitasie van oppervlak myne in ariede gebiede, te evalueer. 'n Goeie begrip van gemeenskap en ekosisteem dinamika sal help om doelwitte en metodes daar te stel vir die rehabilitasie van spesifieke areas. Dit is ook nodig om in Namakwaland, Suid -Afrika, uit te vind watter van die baie faktore, die lang-termyn herstel van 'n ekosisteem, die meeste verhinder. Dit is baie belangrik om In goeie kennis te hê van die versteurings geskiedenis van die area wat gerehabiliteer moet word, asook die suksessionele prosesse wat werksaam is. Plantegroei van areas wat op verskillende tye gemyn en verskillend behandel is, asook ongemynde areas is ondersoek. Sekere areas het In groot mate van herstel gewys in 'n tydperk van 'n paar jaar, terwyl ander, min of geen hersteloor 'n periode van dekades getoon het nie. Dit is belangrik om rehabilitasie as 'n geleidelike proses te sien, wat teen verskillende tempos plaasvind tydens verskillende jare en in verskillende areas. Daar is bevind dat die plant van Atriplex nummularia asook die saai van Atriplex semibaccata nie die terugkeer van inheemse, meerjarige spesies bevoordeel nie, maar dit eerder inhibeer. Aangesien die bo-grond so belangrik is in terme van die grondvrugbaarheid en ook die saadbank wat teenwoordig is, word die invloed van die verwydering en opberging van die bogrond getoets. Die grondvrugbaarheid was bepaal deur groei-toetse op radyse en laboratorium analise op die grond te doen. Die plant spesie diversiteit en rykheid was bepaal met In saad ontkieming studie. In ooreenstemming met die verwagte uitkoms, was die plant spesie diversiteit hoër op die ongemynde bo-grond en die radyse het groter geword op dieselfde grond. Dit kom voor asof die plant spesie diversiteit en rykheid, asook die grond vrugbaarheid afneem met tyd wat die bo-grond geberg word. Die direkte verspreiding van die bo-grond nadat dit verwyder is, sal In medium vir die plante verseker wat nader is aan die vlak voordat die grond versteur is. Dit sal oak sorg vir redelike vinnige en suksesvolle terugkoms van plante op die gemynde grond. Die suksesvolle vestiging van plante hang ook af van die mikro areas (klein areas in terme van die grootte van 'n saad, wat In eie mikro-klimaat vorm), waarna saad versprei word. Die effek van sulke mikro-gebiede op die ontkieming van saad, die groei van die saailinge en die oorlewing van die saailinge was bepaal. Mikro-water- opvanggebiede het in al drie bogenoemde gevalle die hoogste syfers getoon. Die vestiging en oorlewing van saailinge in die ander mikro-gebiede (die area onder enkel struike, die area onder groepe struike en oop areas) het gevarieer afhangend van die hoeveelheid reënval wat ontvang is in die spesifieke jaar. Laastens, is daar ge-eksperimenteer met die oorplant van drie plaaslike, inheemse, sukkulente spesies. Hierdie plante was alleen geplant of in groepies van drie, bymekaar. Die hipotese was dat huloorlewingskanse beter sal wees as hulle saam geplant word. Dit was egter bevind dat die hoeveelheid reënval in 'n spesifieke jaar en die morfologie van die plant, bepaal of hulle sal kompeteer vir die beperkte bronne en of hulle deur saam te groei huloorlewingskanse sal verhoog. Hierdie tesis dra by tot die verstaan van die plantegroei dinamika in die Sukkulente Karoo nadat oppervlak mynbou plaasgevind het. Riglyne vir die rehabilitasie van oppervlak myne, gebasseer op ekologiese prosesse, word ook voorgestel.

Continued expansion of the gold and nickel mining industry in Western Australia during recent years has led to disturbance of larger areas and the generation of increasing volumes of waste rock. Mine operators are obligated to rehabilitate all disturbed surfaces and reconstructed landforms, and considerable effort and expense is now applied to the achievement of this objective. Associated with increasing rehabilitation effort is the requirement to accurately judge rehabilitation success through the development of completion criteria. Completion criteria are rehabilitation performance objectives set as conditions of approval for each stage of rehabilitation and for the project as a whole. They provide standards against which the success of rehabilitation can be measured, or more broadly the point at which responsibility for rehabilitation is complete. The current research project tackles the development of completion criteria by investigating ecosystem function within a variety of rehabilitation trials at four mine sites located in arid and semi-arid Western Australia, and also within surrounding 'natural' vegetation complexes undisturbed by mining, termed analogue sites. Six specific objectives were identified as part of the study: 1. To establish an appropriate end point land use for each mine site where field trials were established; 2. To examine long-term ecosystem development through the assessment of revegetation at a variety of rehabilitation sites; 3. To examine functional components within analogue communities and make appropriate comparisons with rehabilitation trials; 4. To record the potential reproductive capacity of revegetation progeny, and determine how this relates to ecosystem function;5. To provide a better understanding of ecosystem function by investigating the relationship between state factors, interactive controls, and ecosystem processes at rehabilitation and analogue sites; and 6. To develop a methodology for establishing realistic environmental completion criteria at mine sites situated in arid and semi-arid Western Australia. Field trials were established at four mine sites located within three subtly different bioclimatic zones that extend through the arid / semi-arid shrubland belt of Western Australia; Northeastern Goldfields (Granny Smith Gold Mine, Sunrise Dam Gold Mine), Eastern Goldfields (Black Swan Nickel Mine), and Northeastern Wheatbelt (Westonia Gold Mine). 1 The re-establishment of a self-sustaining vegetation cover integrated with the surrounding ecosystem, was the common end land use objective at the four mine sites selected for this study. For three sites located in the Northeastern Goldfields and Eastern Goldfields of Western Australia, sheep were grazed on surrounding rangeland; the fourth site located in the Northeastern Wheatbelt of Western Australia, and was surrounded by Crown Land. 2 To better understand ecosystem function, the dynamic behaviour and interaction of plant biodiversity parameters was monitored regularly at 19 post-mining rehabilitation sites up to 11 years after direct seeding. For functional ecosystems, plant biodiversity parameters changed rapidly during the initial five years after seeding following predictable trends, after which time they remained within a relatively stable range.The stabilising of parameters over time was identified as a key indicator of rehabilitation success, however the point at which the parameters stabilised was influenced by numerous variables and was difficult to accurately predict. Prolific seed germination resulted in high seedling density during the initial growing season. Plant density then progressively decreased in response to competition, before stabilising within a range approximately five years after seeding. Revegetation cover was typically low during the first growing season, increasing rapidly there after before also stabilising in line with plant density. Maximum species richness was generally achieved during the first and second year when annual Atriplex species were prominent. Perennial Atriplex species established more slowly during the early stages of revegetation development, but eventually replaced the annual component as the dominant taxa. Perennial Maireana species required up to three years before germinating in the field and establishing themselves in the revegetation; in many cases they replaced perennial Atriplex as the prominent taxa. The presence or absence of cyclonic rainfall during the first growing season was a major determinant of the ecosystem trajectory, controlling revegetation structure and composition. The germination and successful establishment of hard seeded species, including Acacia and Senna, was reliant on heavy summer rainfall during the early stages of ecosystem development to break seed dormancy and extend the length of the first growing season. This provided an important competitive advantage against faster growing Atriplex species, which possessed greater drought tolerance.The intensity of summer rainfall was also beneficial in leaching surface salts from the upper profile and hence, reducing salinity within the rooting zone. In the absence of heavy summer rainfall during the first growing season, the establishment of a low chenopod dominated vegetation cover was favoured, total species richness for the rehabilitation tended to be lower, and the variety of plant life forms was restricted to low and mid stratum shrubs. Increasing water stress resulted in progressively higher rates of local species extinction, with fewer taxa possessing the drought tolerance adaptations required to survive. For established revegetation, cyclonic rainfall increased productivity (as measured by % foliage ground cover) and stimulated the establishment of new taxa, which in many cases were brought in from adjacent unmined vegetation complexes (analogue sites). While the benefits of summer cyclonic rainfall were undoubtedly important to ari and semi-arid ecosystems, the occurrence of drought was also important in buffering the ecosystem against large-scale change by acting as a negative feedback to constrain cumulative productivity. Parent waste rock material varied considerably between rehabilitation sites, affecting the soil resource supply and associated functional components. Extreme salinity was a typical limitation of the rehabilitation medium, reducing the variety of salt tolerant species and favouring annual Atriplex during the early stages of ecosystem development. The cover of annual species present during early stages of ecosystem development contributed to decreasing salinity in the plant rooting zone, by reducing surface temperature and hence capillary rise of salts during summer months.Annual Atriplex species were replaced by perennial Atriplex in line with decreasing surface salinity. Fundamental to successful revegetation of the post-mining rehabilitation site was the requirement that reconstruction and contouring focus on maximising water retention and reducing salinity within the upper soil profile. Once the initial vegetation community established and plant parameters became relatively stable, change continued to occur, albeit slowly. One factor contributing to this change was the immigration rate of biota from adjacent revegetation or more commonly from surrounding analogue complexes. Linking rehabilitation areas to surrounding functional ecosystems ensured the movement of plants and animals, and ultimately increased the rate of recovery. The sustainability of post-mining rehabilitation was enhanced where these links were established early, allowing for the provision of additional seed and the migration of displaced species. The life cycle pattern of keystone species in the revegetation was found to be an important determinant in long-term sustainability of the plant cover, particularly for chenopod shrublands where one species was typically dominant. The senescence and death of large numbers of a dominant revegetation species together, had the ability to significantly alter the revegetation structure and composition. The impact for rehabilitation where a number of dominant taxa co-exist was less pronounced. Thus it follows that a minimum level of species richness was important to long-term rehabilitation sustainability, as was the development of an age-class structure in the rehabilitation.The most common disturbances encountered at the rehabilitation trial sites were drought, overgrazing and weed infestation. All three disturbances decreased the plant biodiversity parameters measured. Ecosystem recovery following disturbance was dependent on effective rainfall, but occurred rapidly with plant parameters returning to pre-disturbance levels within one to two growing seasons. The recovery of plant biodiversity parameters followed the same trends identified at functional rehabilitation sites during the initial five years following direct seeding. 3 Assessment of plant biodiversity parameters occurred at 15 analogue sites supporting native vegetation undisturbed by mining. It was anticipated that data from analogue sites could be used as a 'reference' against which to compare developing rehabilitation. However, analogue vegetation complexes were less dynamic in comparison to rehabilitation sites. Minor seasonal changes were recorded for plant biodiversity parameters, but overall annual change was minimal. Significant and sudden changes within analogue communities only occurred following disturbance, such as severe overgrazing, and recovery to pre-disturbance levels was rapid following the removal of the disturbance and return of effective rainfall. A major difference between rehabilitation and analogue sites related to their age. Rehabilitation sites were 'juvenile systems' assessed against a time frame much shorter than had been required for natural processes to achieve the developmental state represented at analogue sites.Hence, it was important not to model one specific analogue site too closely, but instead model the desired revegetation structure and species composition on a variety of local analogue complexes occurring in parent materials 'matched' closely to those of the rehabilitation site. Data from analogue sites should be utilised extensively during rehabilitation planning, but cautiously when interpreting the rehabilitation outcome. For mine sites in arid and semi-arid Western Australia, the application of specific numeric targets for plant biodiversity parameters as a measure of rehabilitation success was not recommended. A number of factors and controls in the developing ecosystem together determined the rehabilitation outcome. These factors were site and time specific; minor changes in any number of variables led to significantly different rehabilitation outcomes, making them difficult to accurately predict. 4 Quality and germination testing confirmed progeny seed from a number of rehabilitation trials was of similar or higher viability than the maternal seed originally sown. This was further confirmed by field responses at trials in the Northeastern Goldfields one year after the 1994 drought, when elevated plant density was recorded following the return of above average rainfall. The ability of rehabilitation to show an immediate response to rainfall following a seven-month drought, and for vegetation parameters to subsequently recover to pre-disturbance levels within one to two years, provided an indication that the revegetation cover was resilient. The relationship between plant production and rainfall was dependent on a 'carryover' effect between seasons or following drought years, and 'pulses' mediated, for instance, by the amount of seed in the soil store.The 'reserve' component in and ecosystems was responsible for both the memory of the system between pulses and for its long-term resilience. 6 The analysis of time series data collected from 19 rehabilitation trials emphasized the importance of planning and implementation of best practice techniques to subsequent rehabilitation success, and reinforced the difficulty associated with accurately predicting the final rehabilitation outcome. The large spatial heterogeneity of undisturbed vegetation complexes across the landscape of arid and semi-arid Western Australia, provided the foundation on which site-specific rehabilitation scenarios could be modelled, albeit with caution. The translation of data into useful completion criteria was dependent on the realisation that successful rehabilitation requires the implementation of best practice rehabilitation techniques, as determined by technically prescriptive (design) based standards, as much as the identification of a successful rehabilitation outcome, as determined by performance (outcome) based standards. With this in mind, completion criteria were developed as part of a robust theoretical framework incorporating the larger mine plan, and were not simply based on numbers generated as stand-alone performance standards. The broad methodology generated could be adopted by any mine site across the mining industry, however the criteria and, more specifically, the standards for each criterion should always remain site specific.The methodology designed for developing completion criteria has been addressed in three stages: 1. Planning, 2. Operational and Monitoring, and 3. Post-Mining Hand-Over. Within each stage three parameters are addressed: 1. Criteria, 2. Process, and 3. Standard. 'Planning' is the most important stage in the development of completion criteria. It is the stage when an appropriate end land use is determined, analogue sites are assessed, a rehabilitation plan developed along with specified design standards ensuring implementation of best practice techniques, and a process of risk assessment implemented. The 'Operational Monitoring Stage' focuses on rehabilitation success during the period of ecosystem development. This stage is concerned largely with rehabilitation monitoring, from which performance standards can be developed to gauge rehabilitation success for specific periods during revegetation development. The initial task in Stage 2 is to ensure all aspects of the rehabilitation plan have been implemented as specified in Stage 1, and meet agreed design standards. The final stage of the completion criteria process, 'Post Mining Hand Over', is to ensure the rehabilitated site is safe, and able to successfully revert to the end land use.While plant biodiversity parameters formed the focus of the current study, a variety of other functional ecosystem components may also make sound assessment criteria for determining rehabilitation success. Increasing the knowledge base for other functional components in arid and semi-arid ecosystems would further increase the ability to accurately determine rehabilitation success.

Continued expansion of the gold and nickel mining industry in Western Australia during recent years has led to disturbance of larger areas and the generation of increasing volumes of waste rock. Mine operators are obligated to rehabilitate all disturbed surfaces and reconstructed landforms, and considerable effort and expense is now applied to the achievement of this objective. Associated with increasing rehabilitation effort is the requirement to accurately judge rehabilitation success through the development of completion criteria. Completion criteria are rehabilitation performance objectives set as conditions of approval for each stage of rehabilitation and for the project as a whole. They provide standards against which the success of rehabilitation can be measured, or more broadly the point at which responsibility for rehabilitation is complete. The current research project tackles the development of completion criteria by investigating ecosystem function within a variety of rehabilitation trials at four mine sites located in arid and semi-arid Western Australia, and also within surrounding 'natural' vegetation complexes undisturbed by mining, termed analogue sites. Six specific objectives were identified as part of the study: 1. To establish an appropriate end point land use for each mine site where field trials were established; 2. To examine long-term ecosystem development through the assessment of revegetation at a variety of rehabilitation sites; 3. To examine functional components within analogue communities and make appropriate comparisons with rehabilitation trials; 4. To record the potential reproductive capacity of revegetation progeny, and determine how this relates to ecosystem function;
5. To provide a better understanding of ecosystem function by investigating the relationship between state factors, interactive controls, and ecosystem processes at rehabilitation and analogue sites; and 6. To develop a methodology for establishing realistic environmental completion criteria at mine sites situated in arid and semi-arid Western Australia. Field trials were established at four mine sites located within three subtly different bioclimatic zones that extend through the arid / semi-arid shrubland belt of Western Australia; Northeastern Goldfields (Granny Smith Gold Mine, Sunrise Dam Gold Mine), Eastern Goldfields (Black Swan Nickel Mine), and Northeastern Wheatbelt (Westonia Gold Mine). 1 The re-establishment of a self-sustaining vegetation cover integrated with the surrounding ecosystem, was the common end land use objective at the four mine sites selected for this study. For three sites located in the Northeastern Goldfields and Eastern Goldfields of Western Australia, sheep were grazed on surrounding rangeland; the fourth site located in the Northeastern Wheatbelt of Western Australia, and was surrounded by Crown Land. 2 To better understand ecosystem function, the dynamic behaviour and interaction of plant biodiversity parameters was monitored regularly at 19 post-mining rehabilitation sites up to 11 years after direct seeding. For functional ecosystems, plant biodiversity parameters changed rapidly during the initial five years after seeding following predictable trends, after which time they remained within a relatively stable range.
The stabilising of parameters over time was identified as a key indicator of rehabilitation success, however the point at which the parameters stabilised was influenced by numerous variables and was difficult to accurately predict. Prolific seed germination resulted in high seedling density during the initial growing season. Plant density then progressively decreased in response to competition, before stabilising within a range approximately five years after seeding. Revegetation cover was typically low during the first growing season, increasing rapidly there after before also stabilising in line with plant density. Maximum species richness was generally achieved during the first and second year when annual Atriplex species were prominent. Perennial Atriplex species established more slowly during the early stages of revegetation development, but eventually replaced the annual component as the dominant taxa. Perennial Maireana species required up to three years before germinating in the field and establishing themselves in the revegetation; in many cases they replaced perennial Atriplex as the prominent taxa. The presence or absence of cyclonic rainfall during the first growing season was a major determinant of the ecosystem trajectory, controlling revegetation structure and composition. The germination and successful establishment of hard seeded species, including Acacia and Senna, was reliant on heavy summer rainfall during the early stages of ecosystem development to break seed dormancy and extend the length of the first growing season. This provided an important competitive advantage against faster growing Atriplex species, which possessed greater drought tolerance.
The intensity of summer rainfall was also beneficial in leaching surface salts from the upper profile and hence, reducing salinity within the rooting zone. In the absence of heavy summer rainfall during the first growing season, the establishment of a low chenopod dominated vegetation cover was favoured, total species richness for the rehabilitation tended to be lower, and the variety of plant life forms was restricted to low and mid stratum shrubs. Increasing water stress resulted in progressively higher rates of local species extinction, with fewer taxa possessing the drought tolerance adaptations required to survive. For established revegetation, cyclonic rainfall increased productivity (as measured by % foliage ground cover) and stimulated the establishment of new taxa, which in many cases were brought in from adjacent unmined vegetation complexes (analogue sites). While the benefits of summer cyclonic rainfall were undoubtedly important to ari and semi-arid ecosystems, the occurrence of drought was also important in buffering the ecosystem against large-scale change by acting as a negative feedback to constrain cumulative productivity. Parent waste rock material varied considerably between rehabilitation sites, affecting the soil resource supply and associated functional components. Extreme salinity was a typical limitation of the rehabilitation medium, reducing the variety of salt tolerant species and favouring annual Atriplex during the early stages of ecosystem development. The cover of annual species present during early stages of ecosystem development contributed to decreasing salinity in the plant rooting zone, by reducing surface temperature and hence capillary rise of salts during summer months.
Annual Atriplex species were replaced by perennial Atriplex in line with decreasing surface salinity. Fundamental to successful revegetation of the post-mining rehabilitation site was the requirement that reconstruction and contouring focus on maximising water retention and reducing salinity within the upper soil profile. Once the initial vegetation community established and plant parameters became relatively stable, change continued to occur, albeit slowly. One factor contributing to this change was the immigration rate of biota from adjacent revegetation or more commonly from surrounding analogue complexes. Linking rehabilitation areas to surrounding functional ecosystems ensured the movement of plants and animals, and ultimately increased the rate of recovery. The sustainability of post-mining rehabilitation was enhanced where these links were established early, allowing for the provision of additional seed and the migration of displaced species. The life cycle pattern of keystone species in the revegetation was found to be an important determinant in long-term sustainability of the plant cover, particularly for chenopod shrublands where one species was typically dominant. The senescence and death of large numbers of a dominant revegetation species together, had the ability to significantly alter the revegetation structure and composition. The impact for rehabilitation where a number of dominant taxa co-exist was less pronounced. Thus it follows that a minimum level of species richness was important to long-term rehabilitation sustainability, as was the development of an age-class structure in the rehabilitation.
The most common disturbances encountered at the rehabilitation trial sites were drought, overgrazing and weed infestation. All three disturbances decreased the plant biodiversity parameters measured. Ecosystem recovery following disturbance was dependent on effective rainfall, but occurred rapidly with plant parameters returning to pre-disturbance levels within one to two growing seasons. The recovery of plant biodiversity parameters followed the same trends identified at functional rehabilitation sites during the initial five years following direct seeding. 3 Assessment of plant biodiversity parameters occurred at 15 analogue sites supporting native vegetation undisturbed by mining. It was anticipated that data from analogue sites could be used as a 'reference' against which to compare developing rehabilitation. However, analogue vegetation complexes were less dynamic in comparison to rehabilitation sites. Minor seasonal changes were recorded for plant biodiversity parameters, but overall annual change was minimal. Significant and sudden changes within analogue communities only occurred following disturbance, such as severe overgrazing, and recovery to pre-disturbance levels was rapid following the removal of the disturbance and return of effective rainfall. A major difference between rehabilitation and analogue sites related to their age. Rehabilitation sites were 'juvenile systems' assessed against a time frame much shorter than had been required for natural processes to achieve the developmental state represented at analogue sites.
Hence, it was important not to model one specific analogue site too closely, but instead model the desired revegetation structure and species composition on a variety of local analogue complexes occurring in parent materials 'matched' closely to those of the rehabilitation site. Data from analogue sites should be utilised extensively during rehabilitation planning, but cautiously when interpreting the rehabilitation outcome. For mine sites in arid and semi-arid Western Australia, the application of specific numeric targets for plant biodiversity parameters as a measure of rehabilitation success was not recommended. A number of factors and controls in the developing ecosystem together determined the rehabilitation outcome. These factors were site and time specific; minor changes in any number of variables led to significantly different rehabilitation outcomes, making them difficult to accurately predict. 4 Quality and germination testing confirmed progeny seed from a number of rehabilitation trials was of similar or higher viability than the maternal seed originally sown. This was further confirmed by field responses at trials in the Northeastern Goldfields one year after the 1994 drought, when elevated plant density was recorded following the return of above average rainfall. The ability of rehabilitation to show an immediate response to rainfall following a seven-month drought, and for vegetation parameters to subsequently recover to pre-disturbance levels within one to two years, provided an indication that the revegetation cover was resilient. The relationship between plant production and rainfall was dependent on a 'carryover' effect between seasons or following drought years, and 'pulses' mediated, for instance, by the amount of seed in the soil store.
The 'reserve' component in and ecosystems was responsible for both the memory of the system between pulses and for its long-term resilience. 6 The analysis of time series data collected from 19 rehabilitation trials emphasized the importance of planning and implementation of best practice techniques to subsequent rehabilitation success, and reinforced the difficulty associated with accurately predicting the final rehabilitation outcome. The large spatial heterogeneity of undisturbed vegetation complexes across the landscape of arid and semi-arid Western Australia, provided the foundation on which site-specific rehabilitation scenarios could be modelled, albeit with caution. The translation of data into useful completion criteria was dependent on the realisation that successful rehabilitation requires the implementation of best practice rehabilitation techniques, as determined by technically prescriptive (design) based standards, as much as the identification of a successful rehabilitation outcome, as determined by performance (outcome) based standards. With this in mind, completion criteria were developed as part of a robust theoretical framework incorporating the larger mine plan, and were not simply based on numbers generated as stand-alone performance standards. The broad methodology generated could be adopted by any mine site across the mining industry, however the criteria and, more specifically, the standards for each criterion should always remain site specific.
The methodology designed for developing completion criteria has been addressed in three stages: 1. Planning, 2. Operational and Monitoring, and 3. Post-Mining Hand-Over. Within each stage three parameters are addressed: 1. Criteria, 2. Process, and 3. Standard. 'Planning' is the most important stage in the development of completion criteria. It is the stage when an appropriate end land use is determined, analogue sites are assessed, a rehabilitation plan developed along with specified design standards ensuring implementation of best practice techniques, and a process of risk assessment implemented. The 'Operational Monitoring Stage' focuses on rehabilitation success during the period of ecosystem development. This stage is concerned largely with rehabilitation monitoring, from which performance standards can be developed to gauge rehabilitation success for specific periods during revegetation development. The initial task in Stage 2 is to ensure all aspects of the rehabilitation plan have been implemented as specified in Stage 1, and meet agreed design standards. The final stage of the completion criteria process, 'Post Mining Hand Over', is to ensure the rehabilitated site is safe, and able to successfully revert to the end land use.
While plant biodiversity parameters formed the focus of the current study, a variety of other functional ecosystem components may also make sound assessment criteria for determining rehabilitation success. Increasing the knowledge base for other functional components in arid and semi-arid ecosystems would further increase the ability to accurately determine rehabilitation success.

Current practice for landscape reconstruction following opencast mining relies on topographic reconstruction, adaptive land management and botanical characterisation. Environmental processes may be altered where reconstructed landforms have significant relief. Consequently, environmental outcomes in cases where there is large scale land forming are unpredictable. Moreover, landscape restoration lacks an integrated methodology, and while many mine closures have detailed ecosystem and biodiversity objectives based on natural analogue areas there has been no reliable way to design these objectives into mine landforms. The methods used in landscape restorations to describe reference conditions are based on generalised environmental factors using regional information and incorporating conceptual models. Such models lack the precision and accuracy required to understand and restore hillslope environmental pattern at mine sites. However, methodological integration and statistical inference models underpinning the spatial inference methods in conservation and landscape ecology, and pedology may be applied to solve this problem. These inference models utilise digital terrain models as the core environmental data incorporating ecological theory to predict biodiversity and species distribution. Also, numerical mass balance models such as water and solute balance, which have been applied to understand environmental processes in landscapes, can be used to assess mine landform design. The objective of the work reported here was to investigate environmental variation, with sufficient accuracy and precision, in natural landscapes to design mature mine landforms and to demonstrate the capacity to predict ecological outcomes. This would extend current best practice - designing mine landforms with predictable hydrological and geotechnical outcomes needed to protect off-site environmental conditions – to the on-site environment after closure. The specific aims of this thesis were to: (i) evaluate the predictability of ecosystems based on regional ecological mapping: (ii) develop and evaluate quantitative, site specific environmental mapping and natural analogue selection methodology; (iii) evaluate a trial final landform cover (reconstructed soil) using water balance, water chemistry monitoring; (iv) design and evaluate a conceptual mine landform through the assessment of environmental processes in natural analogue areas; and (v) make valid predictions of revegetation outcomes on the conceptual landform. In meeting these aims, links between ecological theory, landscape analysis and the current practice in mine landform design were identified. The first phase of the thesis involved environmental investigations and surveys of extensive savanna environments on the Tiwi Islands (7320 km-2) and similar environments in the vicinity of Ranger uranium mine (150 km-2) in northern Australia. This first phase, reported in Chapter 3, investigated the reliability of conceptual landscape models used in regional ecological mapping in predicting ecological patterns in terms of vegetation and soil. The Tiwi Islands was selected because of the relatively uniform parent material and its simplified climate. This allowed the study of physiographic control of soil and vegetation patterns. The results identified correlations between vegetation pattern and landform that were confounded by a subjective and complex land unit model of ecosystems. This investigation enabled the development methodological approach to analogue selection and ecological modelling at Ranger uranium mine – a site that will require a restoration approach so as to meet environmental closure objectives. The second phase is the methodological development – involving an initial reconnaissance, is presented in Chapter 4. This phase was aimed at selecting natural analogue areas for mined land restoration. Environmental pattern recognition involving classification, ordination and network analysis was implemented based on methods of conservation ecology. This led to quantitative landscape model to identify natural analogue areas and design ecosystem surveys. This quantitative landscape model incorporated a grid survey of vegetation and soil variation into a nearby analogue landform that matched the area of mine disturbance. This analogue landform encapsulates the entire ecosystem types observed on rocky substrates in the broader reconnaissance survey. The natural analogue selection incorporated a combination of digital terrain analysis and k-means clustering of primary and secondary terrain variables to classify habitat variation on hillslopes. Landscapes with similar extent to the mine landscape were identified from numerical similarity measures (Bray-Curtis) of fine grained habitat variation and summarised using a dendrogram. The range in hillslope ecosystem types were described from stratified environmental surveys of vegetation and soils along environmental gradients in selected analogue landforms. The results show that the mapped environmental factors in close correlation with water and sediment distribution were strongly associated with observed vegetation patterns in analogue areas at Ranger uranium mine. Environmental grain size and landform extent concepts were therefore introduced using landscape ecology theory to integrate different scales of environmental variation in a way that provides direct context with the area impacted by mining. Fine-grained environmental terrain attributes that describe runoff, erosion and sediment deposition were derived from a digital elevation model and classified using non-hierarchical multivariate methods to create a habitat class map. Patch analysis was used to aggregate this fine-grained environmental pattern into a grid that matched the scale of the mine landform. The objective was to identify landforms that were similar in extent to the reconstructed mine landscape. Ecosystem support depends on soil as well as geomorphic factors. An investigation into critical environmental processes, water balance and solute balance, on a waste rock landform at Ranger uranium mine is presented in Chapter 5 to characterise waste rock soils and investigate cover design options that affect environmental support. This involved monitoring of water balance of a reconstructed soil cover on a waste rock landform for four years and the solute loads for two years. A one dimensional water balance model was parameterised and run based on 21 years of rainfall records so as to assess the long-term effects of varying cover thickness and surface compactness on cover performance. The results show that the quality of runoff and seepage water did not improve substantially after two years as large amount of dissolved metal loads persisted. Also, tree roots interacted with the subsoil drainage-limiting layer at one metre below the land surface in just over two years - and thus altering the hydraulic properties of the layer. Further, the results of water balance simulations indicate that increasing the depth to, and thickness of, the drainage-limiting layer would reduce drainage flux. Increasing layer thickness could also limit tree root penetration. It was also found that surface compaction was the most effective means of limiting deep drainage, which contained high concentrations of dissolved metals. However, surface compaction creates an ecological desert. Therefore long-term rehabilitation of the cover will be required to allow water to infiltrate for it to be available for ecosystems. A cover that can store and release sufficient water to support native savanna eucalypt woodland may need to be three to five metres deep, including a drainage limiting layer at depth so as to slow vertical water movement and comprise a well graded mix of hard rock and weathered rock to provide water storage and erosion resistance. The resulting waste rock soils would be similar, morphologically to the gradational, gravelly soils found in natural analogue areas. The study then shifted from mined land back to a selected natural analogue landscape at Ranger mine in Chapter 6. The fine grained variation in terrain attributes is described to support a landform design that allowed for mine plan estimates of waste rock volumes and pit void volumes. A process of developing and evaluating the landform design was put forward, in the case of Ranger, that begins with key stakeholder consultation, followed by an independent scientific validation using published landform evolution and integrated, surface-groundwater water balance modelling. The natural analogue and draft final landforms were compared in terms of terrain attributes, landform evolution and eco-hydrological processes to identify where improvements could be required. The results of the independent design reviews are contained in confidential reports to Ranger mine and in conference proceedings that are referenced in Chapter 6. Independent validation will be a key element of an ecological landform design process and the application of published eco-hydrological and landform evolution models at the Ranger mine case study site are presented as an example of current best practice. Also, detailed assessment was made of environmental variation and soil and geomorphic range in the selected analogue landscape to support the landform design process with the mining department. Ecological modelling of the distributions of framework species in the reconstructed landscape is proposed as an additional assessment tool in this thesis to validate an ecological landform design methodology. To this end, a detailed environmental survey is presented in Chapter 6 of the soils and vegetation in a selected natural analogue area of Ranger mine to identify common and abundant plant species and their distribution in a similar landscape context to the mined land. This work supported ecological modelling of species distributions in reconstructed and natural landscapes in the following chapter. The results of species distribution models for reconstructed and natural landscapes at the Ranger mine site are reported in Chapter 7. The aim was to predict the distribution of common and abundant native woodland species across a landscape comprising a sculpted, post mining landform within a natural landscape. Species distribution models were developed from observations of species presence-absence at 102 sites in the grid survey of the natural analogue area that was reported in Chapter 6. Issues related to optimising predictor selection and the range of environmental support were investigated by introducing survey sites from the broad area reconnaissance survey reported in Chapter 4. Added to these are the published species abundance data from an independent regional biodiversity survey of rocky, well drained eucalypt woodlands, used as analogues of mined land. Plant species responses to continuous and discrete measures of environmental variation were then analysed using multivariate detrended correspondence analysis and canonical correspondence analysis to select independent variables and assess the relative merits of abundance versus presence absence observations of species. Then, generalised additive statistical methods were used to predict species distributions from primary and secondary terrain variables across the natural analogue area and a reconstructed post-mining landform. This analysis was completed with an assessment of the effect that survey support has on model formulation and accuracy. The scale of the mine landscape was found to provide important context for the stratified environmental surveys needed to support predictive modelling. Extending the geographic range of survey support did not improve model performance, while survey sites remote from the mine introduced some degree of spatial autocorrelation that could reduce the prediction accuracy of species distributions in the mine landscape. Further work is needed to address uncommon species or species with highly constrained environmental ranges and aspects of landform cover design and land management that affect woodland type and vigour. The combined studies reported in this thesis show that the predictability of mine land restorations is dependent on the landscape models used to characterise the natural analogue areas. It is demonstrated that conceptual ecological models developed for regional land resources survey, commonly used to select natural analogue areas, are subjective, complex and unreliable predictors of vegetation and soil patterns in hillslope environments at particular sites. It was recognised that environmental patterns are subject to terrain and hillslope environmental variation across an extensive areas. The landform model for selecting natural analogues was refined by introducing grain size and ecological extent concepts, used to describe ecological scale in landscape ecology, to address these effects. These refined concepts were adapted to define environmental variation in the context of natural analogue selection for mining restoration, rather than home range habitat conditions for native animals as was their original purpose. It is demonstrated here that the grain size and extent of environmental variation in the natural landscape can be used to select natural analogue landforms, develop ecological design criteria and design field surveys that support the capacity to predict the distributions of common and abundant woodland species in a reconstructed landscape. In conclusion, it is worth noting that an integrated ecological approach to landscape design can be applied to closure planning at mine sites where cultural and ecological objectives are critical to the success of the mine rehabilitation. Furthermore final landform trials could be used to support a restoration approach — providing an understanding of the interactions between critical physical and ecological processes in the soil layers and environmental processes at catchment scales. The accuracy of the inferences made is dependent on the understanding of hydrological processes in natural and constructed landforms. However, the natural analogue approach provides a clear landscape context for these trials. In a world where species extinction resulting from habitat loss is one of the most important global ecological issues, mine rehabilitation offers unique experimental opportunities to develop capability in ecosystem rehabilitation.

Historically, irresponsible mining companies have escaped their duty to rehabilitate. The Mineral Petroleum Resources Development Act does not oblige mining companies to rehabilitate if their operations ceased before the Minerals Act came into force. In the court case De Beers Consolidated Mines v Ataqua Mining (Pty) Ltd and others 2006 1 SA 432 (T), the court held that the Mineral Petroleum Resources Development Act is not applicable to tailings dumps that were created through mining that had been conducted under the Minerals Act. This ruling leaves unanswered the question about who would be liable to rehabilitate old order tailings dumps once such tailings dumps are re-mined or not mined at all. The aim of this dissertation is to determine whether companies that ceased mining operations before the Mineral Petroleum Resources Development Act came into effect could be held liable for rehabilitation by introducing the scenario that applied in the De Beers court case.
Thesis (LL.M. (Environmental Law))--North-West University, Potchefstroom Campus, 2010

Current methods of mine rehabilitation have a high failure rate at the seedling emergence stage due to the limited availability of topsoil and the low water holding capacity of alternative growth media such as waste materials and tailings. Extruded seed pellets, formed by extruding soil mixtures and seeds into pellets, can potentially increase soil water availability through enhanced soil-seed contact and improve seedling emergence in arid systems. I tested a modified extruded seed pelleting method in a three-factor field experiment in a purpose-built mine rehabilitation research facility in the Pilbara region of northwest Western Australia. The aims of the experiment were to assess (i) native seedling emergence and establishment from modified extruded seed pellets and; ii) the physico-chemical and microbiological changes that occur with seedling emergence from pellets. I tested three native plant species and the experimental factors were pellet soil mixtures, with or without Triodia pungens biomass as an organic amendment and rainfall regimes. Results suggests trade-offs among responses. Pellets made with a 50:50 blend of topsoil and waste material had the highest seedling emergence, while 100 % topsoil pellets had lower emergence probably because of hardsetting. Triodia pungens survived to the end of the experiment but Indigofera monophylla and Acacia inaequilatera did not. Adding Triodia biomass amendment inhibited Triodia seedling emergence but increased soil microbial activity and could therefore stimulate recovery of soil function. Pellets preserved seed viability and topsoil microbial communities during the growing season and therefore show potential as a means to inoculate rehabilitation sites with both seeds and microbes. Overall, modified extruded 50:50 seed pellets show promise for rehabilitation of keystone species Triodia and beneficially, make use of ‘waste’ material. Further research is needed to improve pelleting methodology for other species, and to test the applicability of the method at scale, in this and other arid land ecosystems.

Currently in Western Australia there are no mandated standards for assessing rehabilitation success for the mining industry. A decade ago the focus of most mine site rehabilitation programs was to establish good density and cover of vegetation across the disturbed area. While this resulted in rehabilitated sites that were essentially stable and may have looked aesthetically pleasing, it did not necessarily mean that the rehabilitated sites were moving towards the establishment of functional ecosystems. The goal for rehabilitated mined land should be to restore the structure, diversity, function and dynamics, of the undisturbed ecosystem. In many circumstances this will mean the creation of a self-sustaining, functional ecosystem similar to that in the adjacent undisturbed area from which the rehabilitated area will recruit most of its fauna. The need for 'high-quality' rehabilitation has become necessary with the phasing in of performance standards for assessing the development of rehabilitated mine sites. Mine site rehabilitation should be viewed as managing succession processes towards the creation of ecosystems that are functionally compatible with that which existed before the disturbance or in the adjacent undisturbed areas.

Thesis (MSc)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: The Exxaro Namakwa Sands heavy mineral sands mine at Brand-se-Baai, on the west coast of South Africa, is an important source of income, development and job-creation in the region. However, this comes at a great environmental cost, as strip mining causes large scale destruction of ecosystems through the complete removal of vegetation and topsoil. This is particularly problematic in an environment, such as Namaqualand, where the arid and windy climate, as well as saline and nutrient-poor soils, hamper rehabilitation. These environmental constraints create the need to develop a site-specific rehabilitation program. At Namakwa Sands the objective of rehabilitation is to “rehabilitate and re-vegetate disturbed areas and establish a self-sustaining Strandveld vegetation cover in order to control dust generation, control wind and water erosion, as well as restore land capability. In general, vegetation will be rehabilitated to a minimum grazing standard capable of supporting small stock (sheep) grazing.” In order to achieve this Namakwa Sands conducted rehabilitation experiments with topsoil replacement, seeding of indigenous species and translocation of mature plants. Monitoring is an important part of the rehabilitation process as it allows rehabilitation practitioners to evaluate success and to adapt their management strategies and rehabilitation methods, as well as to evaluate and, if necessary, change their rehabilitation objectives. This study forms part of the monitoring process at Namakwa Sands. It assesses the success of sites that were experimentally rehabilitated in 2001 and a site that was rehabilitated in 2008, using current practice, in order to identify possible management requirements on rehabilitated sites as well as improvements on rehabilitation objectives, methods and monitoring. This study also tests the Landscape Function Analysis (LFA) as rehabilitation monitoring tool by correlating LFA indices with traditional measurements of biophysical variables or their surrogates. Results showed that experimental sites were not successful in returning vegetation cover and plant species richness to the required levels, but did achieve the grazing capacity objective. These sites will need adaptive management to achieve the vegetation cover and plant species richness objectives. The recently rehabilitated site achieved the three-year vegetation cover and plant species richness objectives, as well as the grazing capacity objective, within two years after rehabilitation. Namakwa Sands should therefore continue using the current rehabilitation method. However, rehabilitation should be done in multiple stages in future to decrease the mortality of nursery cuttings and to facilitate the return of late successional species to rehabilitated sites. The sustainability of small stock farming on rangeland with the grazing capacity that is identified as the minimum objective is questionable and this merits further investigation. LFA can be a useful tool to monitor nutrient cycling and soil stability at Namakwa Sands, provided that enough replicates are used. However, LFA cannot be used as is to assess water infiltration at Namakwa Sands, due to assumptions in the calculation of this index that do not hold for the Namaqualand environment. Landscape functioning should be monitored annually to complement vegetation surveys.
AFRIKAANSE OPSOMMING: Die Exxaro Namakwa Sands swaarminerale-sandmyn by Brand-se-Baai, aan die weskus van Suid-Afrika, is ‘n belangrike bron van inkomste, ontwikkeling en werkskepping in die streek. Daar is egter negatiewe omgewingsimpakte aan verbonde, aangesien die strookmyntegniek grootskaalse vernietiging van ekosisteme veroorsaak deur die algehele verwydering van die plantegroei en bogrond. Dit is veral problematies in ‘n omgewing, soos Namakwaland, waar die droë en winderige klimaat, asook die souterige en voedingstof-arme grond, rehabilitasie belemmer. Hierdie beperkings wat deur die omgewing veroorsaak word skep die behoefte om ‘n rehabilitasieprogram te ontwikkel wat spesifiek is tot die terrein. Die doel van rehabilitasie by Namakwa Sands is om te rehabiliteer en herplant op versteurde gebiede en om selfonderhoudende Strandveld plantbedekking te vestig om sodoende stofgenerering te beheer, om wind- en watererosie te beheer, en om grondgebruik-vermoë te herstel. In die algemeen sal plantbedekking gerehabiliteer word tot ‘n minimum weidingskapasiteit wat kleinveeweiding (skaapweiding) kan onderhou. Om dit te bereik het Namakwa Sands rehabilitasie-eksperimente uitgevoer met terugplasing van bogrond, saai van inheemse spesies en oorplanting van volwasse inheemse plante. Monitering is ‘n belangrike deel van die rehabilitasieproses, aangesien dit rehabilitasie-praktisyns in staat stel om sukses te evalueer en om bestuurstrategieë en rehabilitasiemetodes aan te pas, sowel as om rehabilitasiedoelwitte te evalueer en, indien nodig, aan te pas. Hierdie studie vorm deel van die moniteringsproses by Namakwa Sands. Dit assesseer die sukses op persele wat eksperimenteel gerehabiliteer is in 2001 en ‘n perseel wat in 2008 gerehabiliteer is, volgens die huidige praktyk, om moontlike bestuursbehoeftes op gerehabiliteerde persele en verbeteringe aan rehabilitasiedoelwitte, -metodes en –monitering te identifiseer. Hierdie studie toets ook die geskiktheid van die Landscape Function Analysis (LFA) as ‘n rehabilitasie-moniteringsinstrument deur LFA-indekse met tradisionele metings van biofisiese veranderlikes of hul surrogate te korreleer. Resultate dui daarop dat eksperimentele persele nie suksesvol was om plantbedekking en plantspesies-rykdom tot die vereiste vlakke te herstel nie, maar wel die weidingskapasiteit-doelwit bereik het. Hierdie persele benodig aanpassingsbestuur om plantbedekking- en plantspesiesrykdom-doelwitte te bereik. Die perseel wat onlangs gerehabiliteer is, het binne twee jaar na rehabilitasie die drie-jaar plantbedekking- en plantspesiesrykdom-doelwitte, sowel as die weidingskapasiteitdoelwit bereik. Daarom moet Namakwa Sands voortgaan om die huidige rehabilitasiemetode te gebruik. Rehabilitasie moet egter in die toekoms in veelvoudige stadiums gedoen word om die mortaliteit van kwekery-steggies te verminder en om die terugkeer van laatsuksessionele spesies na gerehabiliteerde persele te fasiliteer. Die volhoubaarheid van kleinveeboerdery op weiveld met die minimum vereiste weidingskapasiteit word betwyfel en vereis verdere ondersoek. LFA kan ‘n bruikbare instrument wees om siklering van voedingstowwe en grondstabiliteit te monitor by Namakwa Sands indien genoeg repliserings gebruik word. LFA kan egter nie in die huidige vorm gebruik word om waterinfiltrasie by Namakwa Sands te assesseer nie, aangesien daar aannames in die berekening van die indeks is wat nie juis is in die Namakwaland omgewing nie. Landskapfunksionering behoort jaarliks gemoniteer te word om plantopnames aan te vul.

Thesis (MA)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Remote sensing and vegetation indices were evaluated for its usefulness to monitor the success of the rehabilitation programme of the decommissioned tailings storage facility (TSF1) of the Navachab Gold Mine, Karibib, Namibia. The study aimed to objectively illustrate the rehabilitation progression from tailings (baseline) to soil (capping) and vegetation (planted as well as natural). Baseline data sets of 2004 and 2005 were compared with imagery of 2009, 2010 and 2011. All the images were subjected to panchromatic sharpening using the subtractive resolution merge (SRM) method before georegistration. As no recent accurate topographical maps were available of the study area, the May 2010 image was used as a reference image. All other images were georegistered to this image. A number of vegetation indices (VIs) were evaluated. The results showed that the normalised difference vegetation index (NDVI) and the transformed vegetation index (TVI) provided the most promising results. Although the difference vegetation index (DVI) and enhanced vegetation index (EVI) distinguished the vegetation, rock, and soil classes, it was not as successful as the other VIs in classifying the rain water pond. TVI and NDVI were further evaluated for their efficacy in detecting changes. This was done by generating a series of change images and by qualitatively comparing them to false colour images of the same period. Both the NDVI and TVI delivered good results, but it was found that the TVI is more successful when water is present in the images. The research concludes that change analyses based on the TVI is an effective method for monitoring mine rehabilitation programmes.
AFRIKAANSE OPSOMMING: Afstandswaarneming en plantegroei-indekse is ge-evalueer vir die gebruikswaarde daarvan om sukses van die rehabilitasieprogram vir die geslote slykdam of tailings storage facility (TSF1) van die Navachab Goudmyn, Karibib, Namibië vas te stel. Die studie se doelwit was om die progressie in die rehabilitasie van slyk (basislyn) na grond (dekmateriaal) en plantegroei (aangeplant en natuurlik) te illustreer. Basislyndatastelle 2004 en 2005 is vergelyk met 2009, 2010, en 2011 beelde. Al die beelde is panchromaties verskerp deur die subtractive resolution merge (RSM) metode voor georegistrasie uit te voer. Aangesien geen onlangse, akkurate topografiese kaarte van die studiegebied beskikbaar was nie, is die beeld vir Mei 2010 as ‘n verwysingsbeeld gebruik. Al die ander beelde is op die laasgenoemde beeld gegeoregistreer. Die resultate het gewys dat die normalised difference vegetation index (NDVI) en die transformed vegetation index (TVI) die mees belowende resultate lewer. Al het die difference vegetation index (DVI) en enhanced vegetation index (EVI) goed onderskei tussen plantegroeiklasse en grond- en gesteentesklasse was dit nie so suksesvol met die klassifikasie van die reënwaterpoel nie. TVI en NDVI is verder geëvalueer vir effektiwiteit om verandering waar te neem. Dit is gedoen deur ‘n reeks van veranderingsbeelde te skep en dit dan kwalitatief met die valskleur-beelde vir dieselfde tydperk te vergelyk. Beide die NDVI en TVI het goeie resultate gelewer, maar die TVI was meer suksesvol om beelde met water te klassifiseer. Die navorsing lei tot die gevolgtrekking dat veranderingsanalises met die TVI ‘n effektiewe metode vir die monitoring van rehabilitasie programme is.

This research is on mines that struggle to obtain closure from the state departments. The closure process at the footprints of five Tailings Storage Facilities (TSFs) of a South African gold mine was investigated. They are situated in the Germiston, Brakpan, Springs and Nigel suburbs of the East Rand region of Johannesburg. Very limited scientific research has been done in South Africa on the management of mine closure. The most recent performed research was completed at Coal mines and only one was at an underground gold mine. The history of the case studies at a surface gold mine revealed similar problems, as confirmed in previous research, during the interviews with mine management and the review of operational documents. There is a whole array of causes giving rise to the struggle to obtain closure by a mine, that will be subsequently discussed. Major causes are the lack of estimation of closure costs and the lack of a proper Project Life Cycle (PLC) process for closure by mine management. Previous investigations indicated a general shortfall in estimated closure costs, mining operations that are not planned with closure in mind, closure objectives that are not set at all management levels, final land use after mine closure that is not defined properly, residual and latent impacts that are not dealt with, the post-closure period when the final impact will occur that is not defined and a proper risk assessment based on detailed information that is not properly done and communicated. Another cause is that the integrated process of making closure part of the Environmental Management Programme Report (EMPR) process is not followed. The result of not following the correct process is that mines do not obtain closure. Another reason why mines do not obtain closure is because of an underdeveloped mine infrastructure, e.g. tailings facilities, waste rock dumps, shafts and plants that are not constructed in an environmentally friendly way during the operational phases to facilitate closure. Therefore, these structures need to be changed in terms of their topography and growth medium to ensure an improvement in environmental parameters. This will assist in obtaining sustainability and final closure. Significantly more trust fund money than initially estimated during operations needs to be spent to ensure the above change. Specific issues defined from the case studies were the adaptation of the administration of the closure process, the management of risks, especially the differences in opinions, the management of the mine life cycle for closure and involvement of the land owners and Interested and Affected Parties (l&APs). This research was necessary because companies are uncertain and lack the competency to estimate and to correctly spend trust fund money in order to be sure of obtaining closure. This situation threatens the long-term survival of mining-companies by holding assets and profits back until closure is attained. The state departments also have to address the risks and have to rehabilitate the polluted mine sites if companies do not obtain closure. A proper PLC to facilitate closure was compiled from the above-mentioned data. An important fact to bear in mind is that the activities within the life cycle depend on one another. Therefore, when one activity is disregarded or not properly performed, it will influence the outcome of the remaining activities. The methodology of the research was as follows: Categories to evaluate the closure process of the selected case studies were determined from the project life cycle and the management principles of the literature review. Thereafter a questionnaire was developed from these categories. The questionnaire was subsequently used to guide interviews. After the interviews these categories and findings from the questionnaire were combined and summarised into key findings. The key findings of the research were: • The driving force behind obtaining closure must shift from the State Departments to the mining companies. They must realise there is an opportunity during the closure process to make money and to minimise their long-term liability. The mining company must thus drive the closure process to obtain environmental sustainability. • The gold mines do have problems in terms of cost estimation and trust fund expenditure at their TSF footprints during the closure process. The reasons were a mismanagement of the closure process and making use of a limited information system to make decisions. • A proper closure process does exist, but it can be improved to ensure all interested and affected parties have the same expectations from closure. • There are many activities in the closure process flow diagram which were not properly attended to according to the case studies. • A conceptual closure plan and a draft rehabilitation plan with broad objectives, policies and strategies with detailed descriptions were not compiled during the operational phase, because limited scientific monitoring information was gathered to do a proper risk assessment and some l&APs consultation was done mainly with the material and land owners on a one on one basis. From these key findings the following recommendations could be formulated: • Any mining operation should conduct a closure audit at least every second year and before mining activities change. • A searchable record keeping system must be established to keep track of the closure life cycle development. • Detailed conceptual and final closure plans need to capture the data from the audits and record keeping system. • A communication forum with company management and environmental specialists needs to be established.
Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2009.

Surface-strip coal mine rehabilitation planning in South Africa and Australia is immature. Rehabilitation risk assessment, despite being advocated by leading practice guidelines and in some instances by legislation, is conducted with minimum requirements often met by rehabilitation professionals. Specialist data is gathered during mine approval and for the environmental impact assessment process. However, the focus of this is toward assessing mining impacts and not for rehabilitation risk assessment. Quantitative, integrated, multi-disciplinary rehabilitation risk assessment is seldom undertaken. This thesis provides a methodology towards the development of a quantitative, integrative, multi-disciplinary rehabilitation risk assessment model. Its purpose being to 'profile' surface-strip coal mine sites, in terms of their rehabilitation risk and potential for rehabilitation failure, from the outset of mine operations, with adjustments possible progressively during mine operations. The methodology was developed by first reviewing techniques suitable for the development of the model, as well as techniques developed by others. Bayesian networks (BN) were found to be the most suited. A R2AIN framework was then provided as a process towards developing several BN risk event models that can amalgamate to form a synthesis rehabilitation risk assessment model. A case study soil compaction BN model was used to demonstrate the framework in South Africa and Australia. The case study showed that it is possible to integrate and quantify rehabilitation risk, and most importantly to segregate risk into discrete contributing multidisciplines for analysis. Risk percentages can be calculated per multi-discipline, per mine phase, per site, to aid site risk ‘profiling’. It is recommended that further risk event BN models be prioritised for development and that a rehabilitation risk assessment model be developed to synthesise these into one model. This will require continuous improvements in the method, to build confidence, including extensive risk event and synthesis BN model evaluation and testing; improved BN input node states and values; and simplification of the conditional probability table construction method. Adaptation to other mining types, development activities and other regions should be investigated, as well as spatial linkages to geographic information systems. This research contribution improves upfront mine rehabilitation planning and decision making, providing improved tools and techniques than what currently exist.
Thesis (PhD)--University of Pretoria, 2020.
Geography, Geoinformatics and Meteorology
PhD
Unrestricted

Species prescriptions are developed for revegetating abandoned acidic coal overburden seepage sites in the Collie region of Western Australia. The research involved selecting appropriate plant species and determining successful methods of enhancing revegetation. Candidate species were screened for tolerance to acidic overburden materials, local climate conditions and metal toxicity. Methods tested included improving spoil conditions and trialing an alternative method for seeding.Twelve species of native plants were tested for tolerance in two acid overburden materials in pot and field trials. Eucalyptus robusta is the most tolerant, Eucalyptus camaldulensis and Eucalyptus cladocalyx are highly tolerant, Eucalyptus rudis and Melaleuca hamulosa demonstrate potential, provided adequate soil moisture is available.An important growth restriction factor in acid soils is the presence of free aluminium ions. A glasshouse trial performed on seven species for tolerance to aluminium toxicity revealed E. robusta as most tolerant and E. camaldulensis and Kunzea ericifolia a highly tolerant. E. rudis and M. hamulosa are moderately tolerant, but E. cladocalyx and Eucalyptus diversicolor are very sensitive to aluminium.Various methods were trialed to increase growth of seedlings transplanted on to acidic overburden sites. Both commercial cow manure and slow-release fertiliser tablets increase growth, whereas commercial potting mix and lime do not. Inoculation of plants with the ectomycorrhiza fungus Pisolithus tinctorius increases the amount of infection in roots but does not enhance plant growth.Supplementary fertilisation is necessary to maintain growth (nitrogen) and restore chlorophyll production (phosphorus) in fast growing eucalypt seedlings planted into typical acidic spoils. Poor levels of nutrient availability in such acidic sites appear to be the primary factor in retarding growth. In the absence of supplementation, foliage reddening is observed in several species.An alternative method of seeding dumps is fascining. Prepared dump surfaces may be covered with capsule-laden branchwood of myrtaceous species. Material of the locally available Kunzea ericifolia is effective in producing many seedlings. Subsequent seedling growth is enhanced with fertiliser and lime addition.

Doctor of Philosophy
Department of Agronomy
DeAnn R. Presley
The abandoned lead (Pb) and zinc (Zn) mines in the Tri-State Mining District of Kansas, Missouri, and Oklahoma have left a legacy of environmental contamination. The waste materials are highly polluted, not only with Pb and Zn, but also cadmium (Cd), which often co-occurs geologically with Zn. The District includes Galena, Kansas, where mines operated between 1876 and 1970. Because limited information exists concerning these mines, three studies were done to characterize them and to investigate a way to remediate the mine waste materials. In the first study, the physical characteristics of the mine waste materials were determined. Plots at Galena that had been established by researchers in May 2006 were sampled in November 2014, 8.5 years after they had received amendments (combinations of compost, lime, and bentonite). Water content, bulk density, infiltration rate, unsaturated hydraulic conductivity, aggregate stability, and particle size distribution were determined. The physical characteristics were highly variable, and the amendments added 8.5 years earlier had no effect on them, except the wind erodible fraction (fraction <0.84 mm in diameter) which was low on treatments that contained bentonite. Because biosolids had never been applied to the mine waste materials at Galena for remediation, an experiment was done to see their effect on plant growth and availability of heavy metals. In 2014 the plots established in 2006 were sampled and a greenhouse study was set up with sudex [Sorghum bicolor (L.) Moench x S. Sudanese (P.) Staph]. Plants grew in the mine waste materials with and without biosolids, and 110-111 days after planting the roots, shoots, and heads with grain were harvested and analyzed for heavy metals. At the same time, the mine waste materials were analyzed for heavy metals, organic carbon (C), nitrogen (N), and phosphorus (P). Plants grew better with biosolids than without biosolids, and only the plants grown with biosolids produced heads . Plants grown without biosolids were stunted and showed severe heavy metal toxicity. Organic C and P were increased in the mine waste materials after the addition of biosolids. Thus, the biosolids increased organic C and P, and they apparently made the heavy metals less available for plant uptake. Many studies have shown the importance of attic dust in documenting metal pollution from a mine. Attic dust in Galena had never been studied, so in a third experiment, 14 dust samples in Galena were collected from interiors (attics and one basement) of nine different buildings using two methods: sweeping with a brush and vacuuming. Dust samples were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, and Zn), mineralogy using X-ray diffraction (XRD), scanning electron microscopy (SEM) in conjunction with energy dispersive spectroscopy (EDX), and particle size. Concentrations of Cu, Fe, Mn, Ni, and Zn in the dust were higher than in the mine waste materials. The results from XRD agreed with those from the SEM-EDX analysis. About 10% of each dust sample contained particulate matter (PM) with a diameter of less than 10 μm (PM₁₀), which is a health concern.

Fundamental processes underpinning the biotransformation of coal by fungal biocatalysts have been intensively investigated, however, limited large-scale industrial applications using such systems have been reported. The un-anticipated sporadic growth of Cynodon dactylon on the surface of un-rehabilitated discard coal dumps has been noted and this was found to be coupled with the breakdown of coal into a humic soil-like material in the top 1.5 metres of the dumps. Extensive fungal growth was observed to be associated with the Cynodon dactylon root system and examination of plant roots indicated the presence of mycorrhizal fungi. Analysis of the Cynodon dactylon plant roots around which coal biotransformation was occurring confirmed the presence of arbuscular mycorrhizal colonisation with the species Glomus clarum, Paraglomus occultum, Gigaspora gigantea and Glomus mosseae identified to be associated with the plants. Further molecular characterisation of non-mycorrhizal rhizospheric fungi showed the presence of fungal species with coal-degrading capabilities that most likely played a role in the coal biotransformation observed. The discard coal dump environment was simulated in pot and column studies and coal biotransformation was reproduced, with this process enhanced by the addition of mycorrhizal and non-mycorrhizal rhizospheric fungal inocula to the environment. Mycorrhizal and non-mycorrhizal species in the inoculum were re-isolated from the simulated environment fulfilling a number of Koch’s postulates and indicating a causal role in the biotransformation of coal. An inversion of conventional mycorrhizal colonisation was demonstrated in this system with reduction in extraradicular presence and an increase in intracellular colonisation compared to soil controls. A descriptive model was formulated suggesting a two-part fungal system involving organic carbon and nutrient exchange between the plant, mycorrhizal fungi and non-mycorrhizal coal-degrading rhizospheric fungi ultimately resulting in the biotransformation of coal. The biotransformation observed was comparable to reports of “rock-eating fungi”. Results suggest that the biological degradation of coal in situ with the production of a soil-like substrate could provide a feasible method of discard coal dump rehabilitation as well as provide a humic-rich substrate that can be utilised in further industrial applications.

Species prescriptions are developed for revegetating abandoned acidic coal overburden seepage sites in the Collie region of Western Australia. The research involved selecting appropriate plant species and determining successful methods of enhancing revegetation. Candidate species were screened for tolerance to acidic overburden materials, local climate conditions and metal toxicity. Methods tested included improving spoil conditions and trialing an alternative method for seeding.Twelve species of native plants were tested for tolerance in two acid overburden materials in pot and field trials. Eucalyptus robusta is the most tolerant, Eucalyptus camaldulensis and Eucalyptus cladocalyx are highly tolerant, Eucalyptus rudis and Melaleuca hamulosa demonstrate potential, provided adequate soil moisture is available.An important growth restriction factor in acid soils is the presence of free aluminium ions. A glasshouse trial performed on seven species for tolerance to aluminium toxicity revealed E. robusta as most tolerant and E. camaldulensis and Kunzea ericifolia a highly tolerant. E. rudis and M. hamulosa are moderately tolerant, but E. cladocalyx and Eucalyptus diversicolor are very sensitive to aluminium.Various methods were trialed to increase growth of seedlings transplanted on to acidic overburden sites. Both commercial cow manure and slow-release fertiliser tablets increase growth, whereas commercial potting mix and lime do not. Inoculation of plants with the ectomycorrhiza fungus Pisolithus tinctorius increases the amount of infection in roots but does not enhance plant growth.Supplementary fertilisation is necessary to maintain growth (nitrogen) and restore chlorophyll production (phosphorus) in fast growing eucalypt seedlings planted into typical acidic spoils. Poor levels of nutrient availability in such acidic sites appear to be the primary factor in ++
retarding growth. In the absence of supplementation, foliage reddening is observed in several species.An alternative method of seeding dumps is fascining. Prepared dump surfaces may be covered with capsule-laden branchwood of myrtaceous species. Material of the locally available Kunzea ericifolia is effective in producing many seedlings. Subsequent seedling growth is enhanced with fertiliser and lime addition.

The post-mining land use optimisation framework developed as part of this research underpins the need for examining site-specific decisions within the regional land planning context as well as in relation to the social, economic, and political perspectives within the mine’s localised planning domain. It emphasizes that the spatial and temporal planning and implementation of rehabilitation and land use-related activities remain continually changing throughout the mining life cycle. This implies that amendments, refinements or corrective action should be an integral aspect of this planning, improving the trajectory towards success as new site knowledge and learnings becomes available. Rehabilitation activities should be implemented as soon as site disturbance (construction) starts and maintained throughout the operational and decommissioning periods. More importantly, these activities remain even more pertinent to the monitoring and maintenance period, during which successful implementation of the pre-defined land use/s can be demonstrated. Rehabilitation-, land use and mine closure plans are hence ‘living’, changing tools, aligned towards a common goal – defining a resilient post-mining landscape that will, ultimately, enable harnessing the altered landscapes’ new characteristics to optimise services to post-mining communities that either provides similar resourcing needs from the land, or alternative resources that contribute to the long-term viability of the area.
Dissertation (MSc) - University of Pretoria, 2018.
Coaltech Research Institute, Chamber of Mines
Chamber of Mines
Geography, Geoinformatics and Meteorology
MSc
Unrestricted

The vegetation of greenstone hills in the Kalgoorlie area of the Eastern Goldfields region of Western Australia was studied to identify the key environmental influences on community and species distribution. This information was needed to determine if plant communities of the hills could provide analogues for the rehabilitation of waste rock dumps that are produced as a consequence of open cut mining. The ridges, slopes and flats adjacent to the main slope were examined and the floristic data sorted into communities. Two structurally and floristically distinct alliances were identified, one dominated by eucalypt species and the other by Acacia quadrimarginea. The eucalypt woodland displayed a taller upper stratum and few groundlayer species and was the dominant vegetation of the flats at the base of the hills. The acacia community was a low woodland and is the dominant vegetation of the hill slopes. Both communities were dominant at an equal number of sites on the ridges of the hills. An investigation of the environmental variables found that edaphic, rather than topographic, factors were responsible for the community distribution on the hills. The eucalypt woodland showed a strong affinity to soils derived from calcrete, which had higher levels of electrical conductivity and lower exchangeable sodium percentages than the soils of the acacia low woodland. Under such conditions, the clay fraction of the soil remains in a more flocculated state allowing higher rates of water infiltration and hydraulic conductivity compared to the acacia soils. Soil nutrients were found to have a secondary influence on community distribution and had a greater effect on species distribution within alliances. A study of the seasonal variation in water content of the soils showed that more moisture is retained in the upper soil horizons in the acacia community than in the eucalypt community during the wetter part of the year, indicating the acacia soils had poorer infiltration properties than the eucalypt soils. The distribution of drought tolerant species such as A. quadrimarginea and Prostanthera incurvata was found to be correlated to soil moisture content of the dry season whilst no correlation was found for the eucalypts at any time of the year. Seasonal comparisons of leaf moisture content and xylem pressure potential showed that the eucalypts maintained their total leaf moisture content throughout the year whereas species such as A. quadrimarginea and Allocasuarina campestris recorded high levels of desiccation of their leaf tissue over the summer. The eucalypts also maintained a more consistent pre-dawn xylem pressure potential throughout the year than either A. quadrimarginea or the shrub species Dodonaea microzyga, indicating a greater degree of stomatal control and access to a more consistent soil water supply. The eucalypts require access to a greater soil volume than the acacias or shrubs in order to ensure sufficient water supplies for the maintenance of tissue moisture levels throughout the year. In this way, the eucalypts are able to effectively avoid the summer drought, whereas the acacias and shrubs are able to tolerate desiccation of their leaf tissues over this period. Investigations of the germination requirements and early seedling survival of prominent species from the greenstone hills indicated that fire may be a factor in the regeneration of most hills species. All studied species were either tolerant of or responded positively to the application of dry heat. In relation to seedling establishment on waste dumps, increasing the soil moisture content of waste dump soils increased the germination rate of most species but did not result in greater seedling survival at the end of the first summer. The provision of microsites which encouraged root development and provided protection for the young seedlings was found to be more important in reducing mortality rates in the first year than increasing the total germination. The study emphasized the importance of physical soil factors and the soil moisture regime in the distribution of eucalypt and acacia communities on the greenstone hills. A species' response to drought stress strongly influences its ability to compete for soil water on different soil types. The eucalypts studied in this project dominated on soils where there is better recharge of subsoil water reserves which can be accessed over the summer period to maintain tissue water levels. Acacias are tolerant of tissue desiccation and will compete successfully on shallower soils and where hydraulic conductivity is poor. Although the project was valuable in identifying water relations as the main control on community distribution on the hills, waste dumps are not strictly analogues of intact greenstone hills due to the differences in rock type and profile formation. Electrical conductivity levels are also higher due to extraction processes. However, the environmental relationships of the different species show that the more drought tolerant species such as Allocasuarina campestris, Acacia quadrimarginea and understorey species associated with them, may be suitable species to form the basis of vegetation reinstatement on waste dumps in the Kalgoorlie region.

The vegetation of greenstone hills in the Kalgoorlie area of the Eastern Goldfields region of Western Australia was studied to identify the key environmental influences on community and species distribution. This information was needed to determine if plant communities of the hills could provide analogues for the rehabilitation of waste rock dumps that are produced as a consequence of open cut mining. The ridges, slopes and flats adjacent to the main slope were examined and the floristic data sorted into communities. Two structurally and floristically distinct alliances were identified, one dominated by eucalypt species and the other by Acacia quadrimarginea. The eucalypt woodland displayed a taller upper stratum and few groundlayer species and was the dominant vegetation of the flats at the base of the hills. The acacia community was a low woodland and is the dominant vegetation of the hill slopes. Both communities were dominant at an equal number of sites on the ridges of the hills. An investigation of the environmental variables found that edaphic, rather than topographic, factors were responsible for the community distribution on the hills. The eucalypt woodland showed a strong affinity to soils derived from calcrete, which had higher levels of electrical conductivity and lower exchangeable sodium percentages than the soils of the acacia low woodland. Under such conditions, the clay fraction of the soil remains in a more flocculated state allowing higher rates of water infiltration and hydraulic conductivity compared to the acacia soils. Soil nutrients were found to have a secondary influence on community distribution and had a greater effect on species distribution within alliances. A study of the seasonal variation in water content of the soils showed that more moisture is retained in the upper soil horizons in the acacia community than in the eucalypt community during the wetter part of the year, indicating the acacia soils had poorer infiltration properties than the eucalypt soils. The distribution of drought tolerant species such as A. quadrimarginea and Prostanthera incurvata was found to be correlated to soil moisture content of the dry season whilst no correlation was found for the eucalypts at any time of the year. Seasonal comparisons of leaf moisture content and xylem pressure potential showed that the eucalypts maintained their total leaf moisture content throughout the year whereas species such as A. quadrimarginea and Allocasuarina campestris recorded high levels of desiccation of their leaf tissue over the summer. The eucalypts also maintained a more consistent pre-dawn xylem pressure potential throughout the year than either A. quadrimarginea or the shrub species Dodonaea microzyga, indicating a greater degree of stomatal control and access to a more consistent soil water supply. The eucalypts require access to a greater soil volume than the acacias or shrubs in order to ensure sufficient water supplies for the maintenance of tissue moisture levels throughout the year. In this way, the eucalypts are able to effectively avoid the summer drought, whereas the acacias and shrubs are able to tolerate desiccation of their leaf tissues over this period. Investigations of the germination requirements and early seedling survival of prominent species from the greenstone hills indicated that fire may be a factor in the regeneration of most hills species. All studied species were either tolerant of or responded positively to the application of dry heat. In relation to seedling establishment on waste dumps, increasing the soil moisture content of waste dump soils increased the germination rate of most species but did not result in greater seedling survival at the end of the first summer. The provision of microsites which encouraged root development and provided protection for the young seedlings was found to be more important in reducing mortality rates in the first year than increasing the total germination. The study emphasized the importance of physical soil factors and the soil moisture regime in the distribution of eucalypt and acacia communities on the greenstone hills. A species' response to drought stress strongly influences its ability to compete for soil water on different soil types. The eucalypts studied in this project dominated on soils where there is better recharge of subsoil water reserves which can be accessed over the summer period to maintain tissue water levels. Acacias are tolerant of tissue desiccation and will compete successfully on shallower soils and where hydraulic conductivity is poor. Although the project was valuable in identifying water relations as the main control on community distribution on the hills, waste dumps are not strictly analogues of intact greenstone hills due to the differences in rock type and profile formation. Electrical conductivity levels are also higher due to extraction processes. However, the environmental relationships of the different species show that the more drought tolerant species such as Allocasuarina campestris, Acacia quadrimarginea and understorey species associated with them, may be suitable species to form the basis of vegetation reinstatement on waste dumps in the Kalgoorlie region.

A lot of mine were left abandoned, unrehabilitated or unclosed prior to the introduction National Environmental management Act 107 of 1998 and most did not have plans for rehabilitation or mine closure. The law requires that no exploration or production operations may commence unless financial provision has been made that is guaranteeing the availability of sufficient fund. planning is a prerequisite in the early development planning phase and must continue throughout the mine life cycle and closure phase. The financial provisions must be maintained for the duration of the life of the mine until closure when the closure certificate is issued. The financial provision is critical in ensuring that environmental liabilities for rehabilitation and closure are addressed. The purpose thereof is to mitigate the negative impacts of mining operations on the environment. This paper will investigate financial provisions system which is currently in use in South Africa from the financial security methods employed, the setting up, determination, quantification as well as general rules applicable thereto. The surveys undertaken in this regard and records held by the DMR will be relied on. When mine operations stop, a closure certificate must be issued to serve as proof that the plans relating to reclamation and closure have been complied with. The effect of a closure certificate exonerates the holder of such right from any residual or latent environmental liabilities. The paper will further look into the reasons and barriers to proper mine closure. The overall SA legislative framework for environmental liability relating to closure and rehabilitation generally conforms with international expectations. This paper examines the principal legislation and in particular the 2015 proposed regulations for securing financial provision for environmental liabilities. The main objectives of the research were to evaluate whether the current financial provision systems are appropriate in guaranteeing mine rehabilitation and closure. Moreover, whether they can realistically alter the legacy inherited from past abandoned or unclosed mines. Lastly, examination of the correlation between closure certificate and financial provision in relation to mine closure. Findings indicate that money set aside as financial provision for environmental liabilities is not being spent by the state. The law is clear which steps mine companies must take for rehabilitation and closure of new and old mine sites including legacy abandoned sites. The law is only as good as its implementation and enforcement. The Success of any financial surety instrument depends on the care, effort put into setting it up, managing it and meticulous calculation. Most will work if they are done properly.
Mini Dissertation (LLM)--University of Pretoria, 2019.
Public Law
LLM
Unrestricted

This research is the outcome of investigations of the ability of Nitella congesta, a charophyte, to hyperaccumulate metal contaminants, as well as contribute to the sustainable development of a chain of lakes derived from the sand mine voids at Capel 250km south of Perth, Western Australia. Studies were conducted to ascertain the taxonomy of Nitella congesta as well as its life cycle pattern in relation to the hydrological regime of the lakes of the wetlands. It was observed that a decrease in the availability of water in the lakes particularly on the onset of summer, initiated the production of fruiting bodies whiles prolonged availability of water ensured a prolonged vegetative growth.Aquatic plants play an important role in the structuring of freshwater communities. Freshwater macrophytes such as Nitella congesta have been reported to serve as food source as well as provide refuge and shelter for macroinvertebrates. Thus the presence of freshwater macrophytes in one way or the other has a direct impact on the species abundance and diversity of macroinvertebrates that use them as their habitat. A study of the impact of Nitella congesta as a suitable macrophyte on diversity and abundance of macroinvertebrates showed a positive outcome. It was observed that species richness and diversity were high in Nitella congesta dominated sites of the lakes. Experimental outcome showed that Nitella congesta is a hyperaccumulator of metals. Both the mucilage and the thallus displayed concentrations of few metals.The disappearance of submerged macrophytes such as charophytes in shallow lakes is a major problem caused by eutrophication. There has been an approved proposal to discharge treated waste water with a phosphorus concentration of about 4,000μg/L into the lakes of the Capel Wetlands Centre. This necessitated a study of the impact of eutrophication on the establishment of Nitella congesta as a functional macrophyte for the enhancement of the ecological structure of the wetlands.Results showed that though eutrophication will initially increase the primary productivity of the lakes of the wetlands, the eventual consequence will be the loss of Nitella congesta as a functional macrophyte in the wetlands.At the last stage of the study, a consistent decrease in pH readings of the lakes and lack of successful germination of Nitella congesta as a result of prolonged drought and exposure of the lake sediment was observed. This necessitated a thorough study of the impact of climate change on the establishment of Nitella congesta in the wetlands. In conclusion, it was observed that Nitella congesta could serve as a suitable tool for the rehabilitation of the wetlands.

This research is the outcome of investigations of the ability of Nitella congesta, a charophyte, to hyperaccumulate metal contaminants, as well as contribute to the sustainable development of a chain of lakes derived from the sand mine voids at Capel 250km south of Perth, Western Australia. Studies were conducted to ascertain the taxonomy of Nitella congesta as well as its life cycle pattern in relation to the hydrological regime of the lakes of the wetlands. It was observed that a decrease in the availability of water in the lakes particularly on the onset of summer, initiated the production of fruiting bodies whiles prolonged availability of water ensured a prolonged vegetative growth.
Aquatic plants play an important role in the structuring of freshwater communities. Freshwater macrophytes such as Nitella congesta have been reported to serve as food source as well as provide refuge and shelter for macroinvertebrates. Thus the presence of freshwater macrophytes in one way or the other has a direct impact on the species abundance and diversity of macroinvertebrates that use them as their habitat. A study of the impact of Nitella congesta as a suitable macrophyte on diversity and abundance of macroinvertebrates showed a positive outcome. It was observed that species richness and diversity were high in Nitella congesta dominated sites of the lakes. Experimental outcome showed that Nitella congesta is a hyperaccumulator of metals. Both the mucilage and the thallus displayed concentrations of few metals.
The disappearance of submerged macrophytes such as charophytes in shallow lakes is a major problem caused by eutrophication. There has been an approved proposal to discharge treated waste water with a phosphorus concentration of about 4,000μg/L into the lakes of the Capel Wetlands Centre. This necessitated a study of the impact of eutrophication on the establishment of Nitella congesta as a functional macrophyte for the enhancement of the ecological structure of the wetlands.
Results showed that though eutrophication will initially increase the primary productivity of the lakes of the wetlands, the eventual consequence will be the loss of Nitella congesta as a functional macrophyte in the wetlands.
At the last stage of the study, a consistent decrease in pH readings of the lakes and lack of successful germination of Nitella congesta as a result of prolonged drought and exposure of the lake sediment was observed. This necessitated a thorough study of the impact of climate change on the establishment of Nitella congesta in the wetlands. In conclusion, it was observed that Nitella congesta could serve as a suitable tool for the rehabilitation of the wetlands.

The subject of this thesis is the development of alternative approaches to environmental management and mine closure plans using case examples of the Big Bell/Cue Mining District and as a working example, an area of unconfined washout of historical gold-mine process tailings located in this arid inland region of Western Australia. This is considered appropriate in the light of the social and political thrust for industry to develop simultaneously positive economic, social and environmental outcomes from their activities. The Big Bell mining operation ceased mining in June 2003 and the Mine Closure Plan reflected a classical approach of minimization of public liability and strict compliance with legislative requirements. During the life of the modern mine the approach to rehabilitation was similarly classical in its approach It is intended for this document to inform the mining industry using the case example of the now closed Big Bell Mine as to how greater long-term outcomes may have been achieved for the State and the region for the future. This thesis specifically investigates alternative ways to approach rehabilitation in arid areas of Western Australia using the washout area as an example and trial area. This thesis has approached the issue by addressing the quantification of what has occurred through the gathering of baseline data of the case study area and then by the implementation of a series of relevant trials to identify appropriate eco-functional process-sensitive methods for rehabilitation as an alternative to current industry practice. Trials investigating the use of "retention banks" and "clay/seed balls" and the use of ex-mine milling waste carbon were conducted to investigate relevant possible techniques suitable for arid mine-site waste dump rehabilitation. Data analysis indicated that the main reason for the high level of degradation within the case study area is due to the smothering effect of the fine clayey tails cover and due to acidity of the tailings. A detailed examination of 92 soil samples found water infiltration of tails-washed areas as half that of control areas. Acidity of alluvium has declined from pH 5.2 to 3.8. The acidity has penetrated at depth to hardpan. Trials were commenced to rehabilitate the area using a combination of earthworks (retention banks and· scarification), pH- adjustment (using ex-mill carbon and crushed lime), and the use of native seed pelletised into clay-balls. The introduction of ex-mill carbon was shown to be effective in ameliorating pH in the tails wash area and improving its capacity to regenerate. Considering it is a widely available waste product with the gold mining industry it should be seriously considered in its application for rehabilitation purposes, and specifically in areas affected by severe acidification and desertification particularly by mismanaged tailings with pyrite content. The use of clay balls should also be subjected to further investigation. It is at least equal to the traditional use of raw seed and fertilizer with immediate and abundant rainfall. As this almost never occurs, it should prove to be superior, in delivering higher rates of viability for seed used. The thesis then attempts to integrate this study within the context of the wider issues of environmental management, specifically the best practice of mine closure plans and the adoption of sustainable economic, social and environmental outcomes from mining as an integral part of responsible operational environmental management plans. The thesis argues that the environmental management planning and specifically the Mine Closure Plan should not waste the myriad of opportunities that are the by-product of mining for the long-term sustainable benefit of the wider region. It is argued that if mining companies are serious about sustainability, then they cannot continue with short-term cycles of mining and closure. However to be realistic it will take concerted willingness from all stakeholders to pursue these outcomes. While a given mining operation can offer extensive resources and assets to support this approach the commercial and legislative pressures of core mining activities necessarily mean that mines are in fact encouraged to simply return the environment back to as natural state after operations are complete. Invariably this means hundreds of millions of dollars of infrastructure are levelled and scrapped to avoid all future liability, whilst the potential for sustainable outcomes is essentially ignored. The same Government that enforces the Mining Act and has a State Sustainability Strategy imposes the conditions which create unimaginative classical mine closure plans. Government, industry and the residents of regions must work together to seriously develop sustainable outcomes to mining.

This study investigates coal discard cover soil fertility and its potential for degradation, particularly in terms of its salinisation and acidification potential. Seven rehabilitated coal discard dumps in the Witbank, Ermelo and Newcastle regions were used as study areas. All areas were rehabilitated with a cover soil layer, revegetated and annually fertilised with nitrate fertilisers, super phosphate, kraal manure and lime. Performance guideline for pH of 5.5-(6.5 i0.5)-7.5 and electrical conductivity guideline of preferably less than 200 mS.rn-' but not higher than 400 mS.m-' were set based on literature information. Soil chemical data from a three-year fertilisation programme were used to assess the fertility of the cover soil surface (0-150mm). Data collected over a three year period as well as additional electrical conductivity and pH measurements from the cover soil surface, subsoil, cover soil/coal contact zone and underlying coal itself were used to assess the occurrence of salinisation and acidification of the cover soil. The soil fertility varied significantly among dumps as well as over the three years. Results indicated an increase in ammonium acetate extractable macro elements (calcium, magnesium and potassium). With the exception of manganese, no micro-element toxicities were recorded. Iron concentrations were slightly elevated in some of the sandy cover soil layers. No increase in soluble nitrogen (nitrate and ammonium) was found and most soluble nitrogen was in the form of nitrates. In general the Bray extractable phosphate increased during the study period. It can be predicted that with the following fertiliser programme increases of exchangeable macro-elements as well as available phosphorus can be expected. The study could not indicate an increase in adsorbed or available nitrogen. Organic carbon was initially not analysed therefore no comments can be made whether organic matter increased. Four of the seven dumps surveyed had comparably similar organic carbon levels to the background samples. Overall the fertiliser programme increased the electrical conductivity and decreased the acidity of the cover soil surface. Acidity and salinity was in general not a problem at the surface of the cover soil and pH was even slightly higher in cover soil samples. The acidity and especially salinity increased at the subsoil and so did the sulphate concentrations. Calcium and magnesium sulphate were predominantly responsible for higher electrical conductivity measurements. The percentage exchangeable sodium was also predominantly less than 2% indicating that sodicity is not currently a problem in cover soil. Soil fertility was satisfactory for vegetation growth and macroelement concentrations were in the correct ratio although calcium was slightly high. An elevated sulphate concentration, in comparison to the natural grassland soils, as well as a high salinity and high acidity in the subsoil layers indicate that salinisation and acidification could deteriorate without proper management. A slightly acidic cover soil can also be attributed partially to its natural acidic pH due to the wellweathered and leach property of burrow pit. Higher than recommended salinity levels were found in subsoil samples but the occurrence of acidification of the subsoil was more dump specific. In relation to acidity and salinity guidelines only the cover soil of one dump was concerning and the larger dumps subsoil acidity and salinity were elevated. The following management strategies are proposed: a) The acidification potential, and therefore the pyrite content of the coal discard must be considered during decisions making on the rehabilitation method (clay barriers), topsoil depth, maintenance and mine closure potential. b) The occasional monitoring of the subsoil's and coal contact acidity is recommended, although not much can be done to stop acidification after cover-soil placement. c) To ensure a more sustained from of nitrogen supplementation over the long term the use of selected legumes should be investigated. Research in Europe and Australia suggested that nitrogen fixation could contribute substantially to the nitrogen for plant uptake. d) The physical properties of the topsoil (bulk density 8 soil compaction) are also being neglected and needs to be assessed occasionally and interpreted together with chemical analyses. Observations in other studies indicate that this could be the most fundamental problem for vegetation growth and not necessarily soil fertility, since soil physical properties could have a major impact on root development. Key words: Coal discard, mine rehabilitation, soil fertility, topsoil degradation, salinisation, and acidification
Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2004.

Effects of vegetation cover on runoff and soil loss reduction at mine rehabilitation sites are well documented. However, the knowledge of soil amendment applications, namely polyacrylamide (PAM) and gypsum, prior to the establishment of vegetation is still very limited. These soil amendment methods have proven to have the ability to improve soil surface stability in agriculture, however, the application of soil amendments to improve the spoil surface at mine rehabilitation sites is still un–trialled and their effectiveness largely unknown. This study covers 4 topics namely; (1) to analyse the effectiveness of soil amendments towards improving the hydraulic conductivity of the soil and spoil; (2) to determine the effect of soil amendments application on sediment concentration in the runoff and total soil loss generated from the laboratory based soil erosion experiments; (3) to assess WinSEADS model (Soil Erosion and Deposition Simulation – Windows) to predict sediment concentration and total soil loss under a variety of scenarios; (4) to carry out cost assessment of possible field application of soil amendments under several scenarios. In the small–scale experiments, the application of soil amendments to the soil and spoil was found to be beneficial in increasing the hydraulic conductivity. The results indicate that gypsum is more effective in maintaining a high hydraulic conductivity when compared with PAM. The percentage increase of hydraulic conductivity was found to depend on the soil amendment application rates; and the physical and chemical characteristics of the soil and spoil.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Gold mine waste poses a significant challenge for rehabilitation practitioners and can negatively impact on soil, air, surface water and groundwater quality. This, in turn, can affect the environmental quality of humans and other biota in nearby settlements and surrounding ecosystems. All mines are required to have a plan in place to impede or mitigate these environmental impacts and to ensure that all legislation is complied with to apply for closure. Site closure is the eventual goal of all mine residue complexes, as it is the stage at which a company becomes released from all legal and financial liability. The South African legislation is comprehensive and essentially requires that all latent and residual environmental impacts are addressed and that an end land-use designation is put in place that conforms to the principles of sustainable development. The Chemwes Tailings Storage Facility complex near Stilfontein was monitored to provide a strategic assessment of the state of the rehabilitation, and to provide recommendations for the successful remediation of problem sites. A combination of vegetation sampling, landscape function assessments and substrate chemical analyses were conducted to gain a predictive understanding of rehabilitation progress. The monitoring was conducted over two years across a chronosequence of rehabilitating sites from tailings dam slopes and an adjacent spillage site. An undisturbed grassland and a starter-wall served as reference sites. The data were first analysed independently and then by making use of multivariate data ordinations. This allowed for holistic investigations of the relationships between sites, substrate chemistry, vegetation composition and landscape function. The results showed that the tailings dams had a distinctly different suite of vegetation from the reference sites, but had no statistically significant differences in composition across the rehabilitating chronosequence. There were positive correlations between rehabilitation site age and landscape function indices, suggesting that some aspects of ecosystem development were occurring over time. In some sites, deterioration in the substrate quality as a growth medium was observed with increases in acidity and salinity. This was most likely caused by pyrite oxidation in the tailings and the high concentrations of free salts. The increasing acidity and salinity resulted in vegetation senescence and declines in landscape function. However, those sites that possessed higher landscape function appeared to have the ecosystem processes in place that temporarily suppressed negative chemical changes. Whilst this was encouraging,the rehabilitation chronosequence had not yet proven the self-sustainability that it would require for closure purposes. Further monitoring would be required over time. The sustainability of the rehabilitating chronosequence was brought into question by the high acid-forming potential of the tailings growth medium. Concerns were also raised over the ability of the established vegetation cover to persist under conditions of increasing stress and disturbance. Furthermore, the land-use capabilities of the sites are limited by current rehabilitation procedures and various recommendations were made to rectify this. A more streamlined monitoring framework for the tailings complex was also proposed. The contribution of this work lies in its holistic integration of monitoring techniques and the meaningful analysis of ecosystem function, an aspect largely ignored in minesite rehabilitation.
Thesis (M.Sc. (Environmental Sciences and Management))--North-West University, Potchefstroom Campus, 2009.

[Truncated abstract] Landforms rehabilitated after bauxite mining can be vulnerable to soil loss by water erosion processes. On most rehabilitated sites, management controls such as deep ripping, contour mounding and landscaped sub-catchments limit erosion. Despite these measures, severe gully erosion that is anecdotally associated with steep slopes can damage rehabilitated areas and affect downstream drinking water resources. A review of erosion dynamics reveals that gullies develop episodically and in a non-linear manner. They often initiated as a near surface process and are influenced by natural climatic drivers. Despite this, local site characteristics including soil and landform can predispose an area to gully erosion. Moreover, erosion models, becoming more-widely utilized within the mining industry, may provide useful tools with which to measure, analyse, and manage gully erosion. One of these models, SIBERIA was tested to determine its suitability for application a tool to help manage erosion risk. We first surveyed 26 eroding and erosion-prone rehabilitated hillslopes to determine the common form and setting for gully erosion on these rehabilitated bauxite mines. A conceptual model was developed to include and explore the interplay between the common causes of the gullies surveyed. The conceptual model accounts for slope steepness but suggests that additionally, certain triggers and threshold effects operating under different site conditions are as influential (or even more influential) than slope steepness as determinants of gully erosion occurrence and severity. ... Soil properties and soil erodibility had some subtle influence on landform stability and erosion risk. The most-erodible media occurred where either: mine floor material was mixed with topsoil/ overburden; and/or the topsoil/overburden layer was thin or its coverage is patchy resulting in slaking subsoil, hardsetting soil and surface crusts. When erodible surface media were combined with steeper (>8[degrees]) or longer (>50 m) slopes or with any major erosion trigger, rill and gully development was greatly intensified. The SIBERIA simulation model was calibrated and its simulated outputs were compared to known locations of gully erosion on a steep, rehabilitated pit from the Willowdale mine. At a resolution of one metre, SIBERIA was able to simulate the approximate dimensions of gullies. However, SIBERIA could not simulate the exact location of individual gully headcuts. Additionally, SIBERA was able to simulate the effect of different microtopographic surface treatments but this was only achieved by increasing the grid resolution to 25 cm and reducing the size of the area simulated due to model constraints. Locations of gully headcuts were overlain onto a grid-based, Digital Elevation Model (DEM) using a Geographic Information System (GIS). The spatial distribution of gully headcut locations was compared to DEM derivatives such as slope and flow accumulation. Positive, and predictive relationships allow between the steepness of the slope of the pre-mining landform and the cell count of the area contributing to flow (catchment), as determined by GIS, may allow a mine scale indication of erosion risk using simple GIS desktop analysis.

The breakdown of contaminants in soil resulting from microbial activity that is enhanced in the presence of the plant root zone, rhizosphere, has been termed rhizoremediation. To date, Australian native plants have not been assessed for their hydrocarbon rhizoremediation potential. The use of native plants offers an economically feasible and environmentally sustainable cleanup option for the rehabilitation and restoration of hydrocarbon contaminated sites in Australia. The aim of the study was to evaluate the potential of Australian native grass species for the rhizoremediation of aliphatic hydrocarbon contaminated soil from a mine site. Candidate Australian native grass species Poaceae were selected following the development of essential and desirable growth criteria. Nine perennial Australian grasses were evaluated for seedling emergence in sandy loam soil sourced from a mine site which was artificially contaminated with a 60:40 diesel/oil mix at concentrations of 30 000 mg/kg, 10 000 mg/kg, 5 000 mg/kg and 0 mg/kg control. Seedling emergence was not adversely affected by the presence of hydrocarbon contamination at the exposed concentrations for eight of the nine species studied p > 0.05. Three promising species were assessed for relative growth performance in diesel/oil contaminated 10 000 mg/kg, 5 000 mg/kg and uncontaminated control soils in greenhouse studies to assess their tolerance of aliphatic hydrocarbon contaminated soil. Cymbopogon ambiguus Lemon Scented grass is a summer growing perennial with widespread distribution throughout Australia including the region where the mine site is situated. Brachiaria decumbens Signal grass – naturalised - is adapted to humid tropical areas of Australia and is native to the site and sourced from seed banks. Microlaena stipoides Weeping grass var. Griffin is a cool season grass, widely distributed throughout Australia in moister regions. The three evaluated species survived for 120 days in the diesel/oil contaminated soil at the exposed concentrations without adverse growth affect p > 0.05. In some instances e.g. C. ambiguus growth stimulation occurred in the presence of contamination producing significantly more root biomass compared with the control p < 0.0001. Most hydrocarbon degradation is believed to occur through microbial processes, and so the plant-associated microbial community was examined in the three tolerant species. The assessment of the influence of grass on the abundance and activity of microorganisms in the rhizosphere revealed species-specific plant-induced changes in the soil microbial community. Selective enrichment of hydrocarbon degrading microorganisms was demonstrated in the rhizosphere soil of the Australian grasses tested, to varying degrees. C. ambiguus appeared to have the greatest influence on stimulation of hydrocarbon degrading microorganisms, followed by the cool season grass M. stipoides. B. decumbens showed consistently lower numbers of hydrocarbon degrading microorganisms in rhizosphere soil over time compared to the other two species p < 0.01. The influence of grasses on microbial community structure - defined as community DNA fingerprint - in diesel/oil contaminated soil suggested no new microbial population was favoured by the grasses - qualitative shift - rather there were relative quantitative changes in existing members of the microbial population. Soil lipase activity did not appear to be an optimal bioindicator of rhizoremediation and may encompass total soil microbial activity not exclusively the hydrocarbon degrading microorganisms of interest. The assessment of biodegradation of hydrocarbons in soil is essential to characterise the effectiveness of plant species in rhizoremediation. Residual diesel and oil concentrations as total petroleum hydrocarbons, TPH were measured using Gas Chromatography. The presence of single species successfully enhanced the removal of hydrocarbons from soil for all species. All showed significantly lower residual hydrocarbon concentrations than those in unplanted soil after 100 days p < 0.01. Significantly, it was not necessary to add N and P to achieve up to 90% reduction in hydrocarbon concentrations in the soil. The relative performance of each grass species varied. In soil planted with C. ambiguus hydrocarbon concentrations were reduced faster and to a greater extent than the other species studied, from 10 000 mg/kg to approximately 1 100 mg/kg TPH, 88% removal. Similar endpoint success was recorded for M. stipoides which facilitated 80% reduction in hydrocarbon concentrations. Interestingly, B. decumbens, the only naturalised species, did not perform as well as the other species, although still significantly better compared to unplanted controls, with hydrocarbon concentrations reduced to approximately 4 500 mg/kg, 49%. Hydrocarbon concentrations in unplanted control soil were reduced by 45% through natural biodegradation processes. Plant root and shoot tissue was periodically assessed for hydrocarbon accumulation and was shown to be negligible. A multispecies planted trial using C. ambiguus plus B. decumbens had no additional influence on total TPH removal. The final TPH removal efficiency in the multispecies trial was not significantly different p > 0.05 from that of the best single species performer of the two i.e. C. ambiguus. In a field application the planting of multiple species may still be desirable in order to preserve site biodiversity and assist rehabilitation of the area. A strong relationship between abundance of hydrocarbon degrading microorganisms in the rhizosphere and hydrocarbon biodegradation was demonstrated for all species p < 0.01. Those species which showed greatest stimulation of the microbial population resulted in enhanced TPH removal from soil. These species were the summer grass C. ambiguus and the winter species M. stipoides. This may allow for broader application both seasonally and geographically across Australia. B. decumbens showed successful rhizoremediation to a lesser degree, but may still be an option in multiple planting strategies. This investigation identified three Australian grass species from the nine evaluated that are candidates for further investigation for in situ rhizoremediation potential at field scale.

[Truncated abstract. Please see the pdf format for the complete text. Also, formulae and special characters can only be approximated here. Please see the pdf version for an accurate reproduction.] This thesis examines the water use, ecophysiology and hydraulic architecture of Eucalyptus marginata (jarrah) growing on bauxite mine rehabilitation sites in the jarrah forest of south-western Australia. The principal objective was to characterise the key environment and plant-based influences on tree water use, and to better understand the dynamics of water use over a range of spatial and temporal scales in this drought-prone ecosystem. A novel sap flow measurement system (based on the use of the heat pulse method) was developed so that a large number of trees could be monitored concurrently in the field. A validation experiment using potted jarrah saplings showed that rates of sap flow (transpiration) obtained using this system agreed with those obtained gravimetrically. Notably, diurnal patterns of transpiration were measured accurately and with precision using the newly developed heat ratio method. Field studies showed that water stress and water use by jarrah saplings on rehabilitation sites were strongly seasonal: being greatest in summer when it was warm and dry, and least in winter when it was cool and wet. At different times, water use was influenced by soil water availability, vapour pressure deficit (VPD) and plant hydraulic conductance. In some areas, there was evidence of a rapid decline in transpiration in response to dry soil conditions. At the end of summer, most saplings on rehabilitation sites were not water stressed, whereas water status in the forest was poor for small saplings but improved with increasing size. It has been recognised that mature jarrah trees avoid drought by having deep root systems, however, it appears that saplings on rehabilitation sites may have not yet developed functional deep roots, and as such, they may be heavily reliant on moisture stored in surface soil horizons. Simple predictive models of tree water use revealed that stand water use was 74 % of annual rainfall at a high density (leaf area index, LAI = 3.1), high rainfall (1200 mm yr-1) site, and 12 % of rainfall at a low density (LAI = 0.4), low rainfall (600 mm yr-1) site, and that water use increased with stand growth. A controlled field experiment confirmed that: (1) sapling transpiration was restricted as root-zone water availability declined, irrespective of VPD; (2) transpiration was correlated with VPD when water was abundant; and (3) transpiration was limited by soil-to-leaf hydraulic conductance when water was abundant and VPD was high (> 2 kPa). Specifically, transpiration was regulated by stomatal conductance. Large stomatal apertures could sustain high transpiration rates, but stomata were sensitive to hydraulic perturbations caused by soil water deficits and/or high evaporative demand. No other physiological mechanisms conferred immediate resistance to drought. Empirical observations were agreeably linked with a current theory suggesting that stomata regulate transpiration and plant water potential in order to prevent hydraulic dysfunction following a reduction in soil-to-leaf hydraulic conductance. Moreover, it was clear that plant hydraulic capacity determined the pattern and extent of stomatal regulation. Differences in hydraulic capacity across a gradient in water availability were a reflection of differences in root-to-leaf hydraulic conductance, and were possibly related to differences in xylem structure. Saplings on rehabilitation sites had greater hydraulic conductance (by 50 %) and greater leaf-specific rates of transpiration at the high rainfall site (1.5 kg m-2 day1) than at the low rainfall site (0.8 kg m-2 day1) under near optimal conditions. Also, rehabilitation-grown saplings had significantly greater leaf area, leaf area to sapwood area ratios and hydraulic conductance (by 30-50 %) compared to forest-grown saplings, a strong indication that soils in rehabilitation sites contained more water than soils in the forest. Results suggested that: (1) the hydraulic structure and function of saplings growing under the same climatic conditions was determined by soil water availability; (2) drought reduced stomatal conductance and transpiration by reducing whole-tree hydraulic conductance; and (3) saplings growing on open rehabilitation sites utilised more abundant water, light and nutrients than saplings growing in the forest understorey. These findings support a paradigm that trees evolve hydraulic equipment and physiological characteristics suited to the most efficient use of water from a particular spatial and temporal niche in the soil environment.

[Truncated abstract] Establishment of vegetation and ecosystem functioning is central to the mitigation of environmental impacts associated with mining operations. This study investigated the ecophysiological functioning of mature plants in natural vegetation and applied this knowledge to diagnose problems affecting plant health and causes of poor plant cover at a mine-rehabilitation site. Ecophysiological parameters, including plant water relations and mineral nutrition, were studied in conjunction with soil physical, hydraulic and chemical properties. The natural ecosystem at the study location in the Great Sandy Desert is characterised by sand dunes and interdunes with distinct plant communities on each. One of the most notable features of the vegetation is the presence of large Corymbia chippendalei trees high on the dunes and relatively small scattered shrubs in the interdunes. Triodia grasses (spinifex), dominate the vegetation in both habitats but different species occur in each; T. schinzii is restricted entirely to the dunes, and T. basedowii occurs only in the interdunes. It was hypothesised that the deep sandy dunes afford greater water availability but lower nutrient supply to plants in this habitat compared with those occurring in the lower landscape position of the interdunes. Water-relations parameters (leaf water potentials, stomatal conductance, d13C) revealed that dune plants, particularly woody species, displayed higher water status and water use than closely related and often congeneric plants in the interdunes. Nutrient concentrations in soils were significantly higher in the interdunes, but concentrations in foliage were similar for related species between habitats. It is concluded that the dunes provide a greater store of accessible water than the soil profile in the interdunes. ... Following an experimental wetting pulse equivalent to a summer cyclone event, A. ancistrocarpa plants displayed significant increases in stomatal conductance, leaf water potential and sap velocity in lateral roots within three days of irrigation at the natural site and two days at the rehabilitation site. Secondary sinker roots originating from distal sections of lateral roots were evidently supplying water to maintain hydraulic function in laterals, thus enabling a fast pulse response. This was accentuated at the rehabilitation site where roots were confined closer to the surface. These results indicate that plants at the rehabilitation site are more dependent on small pulses of water and have less access to deep reserves than plants at the natural site. It is concluded that high runoff losses and insufficient soil depth are major factors contributing to plant water stress, and combined with the direct impacts of erosion, are largely responsible for plant death and ultimately poor plant cover. These issues can be alleviated if cover soil depth is increased to more than 0.5 m and slope angles are reduced to <12o. This study demonstrates the value of an ecophysiological approach for diagnosing problems affecting plant establishment at mine-rehabilitation sites. Furthermore, it has provided recommendations that will improve the rehabilitation strategy and lead to the development of a well vegetated, resilient ecosystem on a stable and non-polluting land form.

A mineração promove alterações significativas nos atributos do solo. Freqüentemente o substrato, proveniente de materiais estéreis do processo minerador, serve como meio de crescimento da vegetação das áreas em recuperação ambiental. Um procedimento para monitoramento da qualidade do substrato dessas áreas foi desenvolvido e testado. Os estudos foram conduzidos em uma mina de areia industrial situada no interior do Estado de São Paulo que apresenta cronosseqüência de medidas de restabelecimento de vegetação nativa em bacias de disposição de rejeitos de tratamento de minério, permitindo a simulação do monitoramento por um período de 14 anos. Foram analisadas as mudanças das características físico-químicas do substrato em conjunto com as mudanças na vegetação. Como resultado, verificou-se uma evolução positiva na qualidade do substrato que acompanha o desenvolvimento das espécies implantadas e conclui-se que as variáveis estudadas têm plena possibilidade de atuarem como indicadoras de desempenho da revegetação. Deste conjunto de variáveis, a densidade de solo, os teores de matéria orgânica e fósforo e o pH são os indicadores mais apropriados para avaliar o estado da revegetação, especificamente para as condições do ambiente das bacias de rejeito estudado. As áreas avaliadas encontram-se estabilizadas e contêm uma comunidade vegetal já formada. Contudo, a compactação do substrato, os baixos teores de matéria orgânica e o crescimento invasivo de Brachiaria decumbens (capim braquiária) foram identificados como fatores adversos que dificultam uma melhoria mais contundente na comunidade estabelecida. Concluiu-se que o método proposto constitui um instrumento prático para se obter parâmetros numéricos que permitam uma avaliação quantitativa e objetiva das áreas revegetadas e dos resultados das medidas de recuperação ambiental. Os indicadores podem ser utilizados em conjunto com parâmetros específicos que descrevam o estado da comunidade vegetal. Adicionalmente, podem ter aplicação em minerações de outros bens minerais, particularmente no caso de recuperação ambiental de bacias de disposição de rejeitos.
Mining is an agent of significant changes in soil properties. Successful land rehabilitation depends on restoring those characteristics in natural soils or establishing a suitable substratum for plant growth using available materials such as waste rock or mineral tailings. A process for monitoring the quality of the substratum in mine-affected areas was developed and tested. The study was carried out at an industrial sand mine located in São Paulo State, Brazil. Different plots situated in a tailings pond were restored with native species by the company for the past 14 years, allowing for 10+ years of simulated monitoring. Soil samples were collected to measure a series of physical and chemical substratum properties. Indicators of vegetation development were collected in each plot. As a result, a positive quality evolution of the substratum is observed simultaneously with the development of planted trees. In conclusion it was verified that observed substratum variables have ample possibilities to be suitable as revegetation performing indicators. From all substratum variables studied, soil density, organic matter, P contents and pH are the most appropriated indicators, specifically in the environmental conditions of the tailings pond studied. All evaluated areas feature a well established vegetal community. However substratum compaction, low contents of organic matter and intense weed growing (Brachiaria decumbens) were identified as limitative. The proposed method sets up a practical instrument to obtain quantitative parameters that allow for an objective assessment of revegetated areas and environmental rehabilitation actions. The indicators may be applied to other types of mines, specifically in case of tailing disposal sites.

Rehabilitation is a dynamic process influenced by factors related to more than one field of ecology. It is therefore necessary to consider all these components when assessing the rehabilitation, although in the initial stages the successful revegetation of the disturbed areas is the most important criterion. Richards Bay Minerals, on whose mining site this project was carried out, is dredge mining heavy minerals on the north coast of Natal, where they have rehabilitated mined areas since 1978. This project has been carried out to establish: 1) The success of their dune forest rehabilitation using quantitative techniques. 2) The available seed bank in their rehabilitation stands. 3) The similarities in the succession taking place in rehabilitation stands compared to the revegetated stands in the vicinity of Richards Bay. 4) The best methods for creating alternative vegetation communities, especially grasslands, with a high species diversity on the mined tailings. This study reviews only the success of rehabilitation of the natural vegetation but other studies focusing on the insect, reptile, mammal and bird populations are also being undertaken by other researchers. No particular method of determining the success of vegetation rehabilitation has been chosen by restoration ecologists. Therefore in this study a broad range of quantitative techniques were used to show whether successional changes are occurring in the vegetation and physical environment. The results obtained from sampling the rehabilitated vegetation have shown that both the species richness and diversity are increasing as the returned vegetation matures. Levels of soil properties such as Sodium, Phosphate, Calcium and percentage organic matter have also risen with increasing stand age. Community complexity is also increasing with stand age, and TWINSPAN and DECORANA plots have separated out the differently aged stands based on their differences. A "pilot" study was done on the seed bank present in the rehabilitation stands. This has shown the presence of large amounts of early successional, mostly herbaceous species. Seeds of later successional and woody species were scarce which may be a result of the sampling intensity used. However seeds of late successional ground cover species were found in the older stands. Comparisons between the natural revegetation of disturbed areas in the vicinity of Richards Bay and the rehabilitation stands revealed similarities in both species composition and complexity. Species richness and diversity values are comparatively similar for the younger revegetated and older rehabilitation stands, and lWlNSPAN and DECORANA analysis techniques clustered the samples recorded from these areas in close proximity on their relative plots. The oldest revegetated sites contain a number of species found in the rehabilitated vegetation but as Acacia karroo has thinned-out in these stands many of these other species are now mature individuals. Attempts at rehabilitating an area of grassland at Richards Bay Minerals has not produced satisfactory species diversity and experimental manipulations were used to try and increase the diversity of the existing Eragrostis curvula dominated community. Of the several treatments used for the manipulation, a combination of burning and further topsoiling was the most successful in reducing Eragrostis importance and in increasing the species richness. Grassland topsoil spread directly onto the bare tailings produced an extensive vegetation covering over a short period but species richness was not significantly greater than for the existing Eragrostis dominated grassland, and further treatments and management needs to continue if this technique is to be employed. Only a limited amount of alien infestation of the rehabilitated areas was evident from the sampling undertaken during this research. As the removal of alien plants is an ongoing process and the rehabilitation stands are continuously monitored to identify any new invaders, this is not expected to become a problem. From the results of work done overseas and the rehabilitation carried out in South Africa it appears that it is possible to return natural vegetation communities on mined areas. That this is a lengthy process is to be expected but by manipulating the vegetation and continuously monitoring the process it may be possible to speed up development. Areas in need of further research have been identified based on the findings of this project. This will help to reinforce the undertaking of management proposals that will enhance the vegetation recovery and the success of the rehabilitation programme.

The coal mining industry has played a significant role in the development of the South African economy. Coal supplies about 70% of South Africa's primary energy and is likely to remain the country's major source of energy despite the increasing trends towards renewable energy. Even though the industry has significantly contributed to the development of the country, it has also caused significant impacts on the environment with concomitant socio-economic impacts. Historically, once a coal measure was exhausted, mining companies would cease production and abandon the mines without proper rehabilitation of the environmental degradation caused by their mining activities. As a result of this, the South African Government introduced mining and rehabilitation legislation to mitigate the environmental and associated socio-economic impacts of mining. Rehabilitation guidelines for opencast coal mines were developed to provide detailed guidance for achieving successful and sustainable rehabilitation, to mitigate pollution post-mining. Despite the more stringent legislative framework and the development of international standard rehabilitation guidelines, successful mine rehabilitation remains a challenge. This research project aims to develop a better qualitative understanding of the status, challenges, gaps and opportunities pertaining to current rehabilitation practices in the case of opencast coal mines in the Mpumalanga Province of South Africa, and in so doing, establish the contributing factors of unsuccessful rehabilitation. The dissertation draws on a comprehensive review of published literature and an analysis of semi-structured interviews with rehabilitation experts. The study found that the current rehabilitation practices in the Mpumalanga opencast mines are not to the standard required by the legislative framework nor prescribed by rehabilitation guidelines. As such, the current rehabilitation practices are not yielding successful and sustainable rehabilitation. According to the findings, the rehabilitation practices are hampered by physical and non-physical systemic challenges that thwart the achievement of successful rehabilitation. The study analysis shows that shortcomings in the application and enforcement of the legislative framework contributes to the legislation not achieving its intended objectives as well as the development of other physical and non-physical systemic challenges that hamper the achievement of successful rehabilitation.

This project explores opportunities in designing hybrid digital/physical smell rehabilitation video games using no unique game peripherals. During a 13-week process, three major iterations were created and externally tested on a small user group. The first two iterations contained five simple minigames that served to explore different types of game concepts. For the final iteration, two minigames were fully developed, a slow- and fast-paced game. The main findings were that slow-paced better-facilitated smell training than fast-paced games; aesthetics increased the player’s focus on small training; not utilising unique game peripherals limited the design opportunities and implementation of smell mechanics.

[Truncated abstract] Recovery of soil nutrients, microbial populations and carbon (C) and nitrogen (N) cycling processes are critical to the success of rehabilitation following major ecosystem disturbance. Bauxite mining represents a major ecosystem disturbance to the jarrah (Eucalyptus marginata) forest in the south-west of Western Australia. Mining has created a mosaic of mined areas in various stages of succession surrounded by non-mined forest areas. Initial site preparations within rehabilitation areas such as contour ripping alter soil structure (creation of mound and furrows) and over time also influence the distribution of vegetation and litter. Current performance criteria developed by industry, government and other stakeholders have determined that before post-bauxite mined areas of jarrah forest can be integrated back into normal forest management practises they should be functional and demonstrate resilience to normal forest disturbances such as fire. Furthermore, resilience should be of a manner comparable to non-mined analogue forest sites. Currently little is known of the resilience of microbial communities and C and N cycling in rehabilitation sites to normal forest disturbances such as prescription burning. As such, before rehabilitated jarrah forests can be successfully integrated into broad scale forest management regimes, a more thorough knowledge of the potential impacts of burning practises on the soil microbial community and C and N cycling processes in these systems is required. ... While there are similar rates of C and N cycling the underlying microbial community structure was distinctly different; implying a high degree of functional redundancy with respect to C and N cycling. Differences in the C and N cycling and structure of the microbial communities were likely to be due to differences in soil environmental conditions (i.e. soil alkalinity/acidity, soil moisture) and C substrate availability which influence the physiological status of the microbial community and in turn are related to successional age of the forests. Results also suggest that the measurement of CLPP can be a useful approach for assessment of changes in the functional ability of microbial communities. However, the interpretation of how well these rehabilitation forests have recovered heterotrophic abilities was greatly affected by the methodological approach used (e.g. MicroRespTM or Degens and Harris, 1997). Importantly, results from Chapter 4 and 5 suggested that the effects of a moderate prescription fire on C and N processes, CLPP and microbial community structure of 18 year old rehabilitation forests are likely to be short-lived (< 2 years). Furthermore, the effects of the moderate spring prescription fire were not large enough to decouple C and N cycling processes over the short-term (< 1 years) which suggests that by 18 years of age rehabilitation forests demonstrate comparable functional resilience to a moderate prescription burn.

Degree of Master of Forestry (Conservation Ecology)
Thesis (MSc)--Stellenbosch University, 2003.
Full text to be digitised and attached to bibliographic record.
ENGLISH ABSTRACT: This study investigates the use of top-soiling, irrigation and translocating indigenous plants to facilitate the cost-effective return of a mined landscape to its former land-use (small stock farming) in an arid winter rainfall Succulent Karoo shrub land biome on the West Coast of South Africa. Effects of topsoil stockpiling and subsoil mineral concentration on soil fertility and chemistry were investigated, as soils are likely to determine rates of vegetation recovery on post-mined areas. Results of a radish bioassay show that stockpiling topsoil and mineral concentration subsoil decreased soil fertility. Mineral concentration decreased phosphorus, potassium, calcium, magnesium, carbon and nitrogen levels significantly relative to other soil treatments. Sodium in freshly deposited tailings was at potentially toxic levels and significantly higher than for all other soil treatments. Spreading of stockpiled topsoil over tailings may ameliorate harsh conditions created by mineral separation. Translocation of plants from pre-mined to post-mined areas was carried out on a trial basis in an effort to facilitate the return of natural vegetation and processes to strip-mined landscapes. Five local indigenous plant species: Asparagus spp., Ruschia versicolor, Othonna cylindrica, Lampranthus suavissimus and Zygophyllum morgsana were planted into multi-species clumps in a replicated experiment. Variables examined in the translocation trial included the effects of plant origin, soil treatment and/or irrigation on plant survival and establishment. The proportion of O. cylindrica transplants surviving for 15 months was greater than for other species. Whole plants survived better than salvaged plants, and Asparagus spp., R. versicolor, L. suavissimus and Z. morgsana survived better on stockpiled topsoil spread over tailings than on tailings alone. Irrigation had no consistent effect across species and treatment replicates. Salvaged-plant clumps were significantly larger than whole-plant clumps at planting, however, this effect was not observed after 12 months, indicating that whole-plant clumps grew faster than salvaged-plant clumps. The evergreen, leaf succulent shrubs O. cylindrica, L. suavissimus and R. versicolor appeared to be most suitable for large-scale translocation at Namakwa Sands. The return of biodiversity and changes in soil quality 15 months after translocation trials began were compared for combinations of top-soiling, irrigation, plant translocation and unmodified tailings. Irrigation may reduce biodiversity and seedling densities. Over a 15-month period following back filling and topsoil spreading, sodium, potassium and calcium appeared to return to levels observed for undisturbed soils. Magnesium remains at levels lower than in pre-mined soil conditions. Soil conditions may be more conducive to plant establishment and rehabilitation after back-filling of tailings and topsoil spreading. Electrical resistance increased over time indicating a reduction of free salts and salinity on rehabilitation sites. Phosphorus did not return to pre-disturbance levels, and carbon remained below pre-mining levels for at least 15 months after rehabilitation began, remaining a potential limiting factor in rehabilitation. Each rehabilitation technique that a mine employs has costs and benefits, and it is increasingly important that insights from ecology and economics are coupled if restoration efforts are going to succeed. A review of valuation systems indicates that Discounted Cash Flow Techniques (DCF) are suitable for valuation of rehabilitation operations.
AFRIKAANSE OPSOMMING: Hierdie studie ondersoek die gebruik van bogrond, besproeiing en die oorplanting van inheemse plante om die koste-effektiewe rehabilitasie van 'n stroopmynlandskap in die droë, winter reënval streek, Vetplant Karoo aan die Weskus van Suid-Afrika, wat vroeër gebruik is vir kleinvee boerdery, te bespoedig Die uitwerking van bogrondopberging en minerale konsentrasie op vrugbaarheid en chemise komposisie van grond is ondersoek, aangesien dié gronde gewoonlik die herstelspoed van plantegroei op 'n ou myn terein bepaal. Uitslae van radys proewe toon dat berging van bogrond en minerale konsentrasie van die onderliggende grond vrugbaarheid van grond laat afneem. Mynaktiwiteite en die minerale konsentrasie lei tot 'n betekenisvolle verlies aan fosfaat, kalium, kalsium, magnesium, koolstof en stikstof as die geval met ander bedrywighede. Die vlak van natrium in oorgeblywende sand na die minerale ekstraksie is hoogs giftig en is veel hoër as na ander bedrywighede. Die toediening van bogrond oor die oorblywende sand verbeter die toestand wat deur die skeiding van minerale veroorsaak is. Oorplasing van plante vanaf ongemynde na rehabilitasie gebiede is op proefbasis uitgevoer in 'n poging om die terugkeer van natuurlike plantegroei by die strookmyn te bespoedig. Vyf plaaslike inheemse plantspesies: Asparagus spp., Ruschia versicolor, Othonna cylindrical, Lampranthus suavissimus en Zygophyllum morgsana is in multi-spesie groepe geplant. Veranderlikes getoets tydens hierdie proef sluit in plantoorsprong, grond behandeling, en/of besproeiing, op die oorlewing en vestiging van plante. 'n Groter proporsie O. cylindrical as enige ander spesie het na 15 maande oorleef. Heel plante het beter oorleef as beskadigde plante. Asparagus spp., R. versicolor, L. suavissimus en Z. morgsana het beter oorleef op gebergde bogrond oor oorblywende sand as op oorblywende sand self. Besproeiing het nie 'n volgehoue uitwerking gehad op spesies of op herhaalde replisering nie. Beskadigde plantgroepe was groter as heelplant groepe toe hulle geplant is maar na 12 maande is opgemerk dat die heel-plante vinniger gegroei het. Die immergroen vetplante, 0. cylindrical, L. suavissimus en R. versicolor blyk die mees geskik vir grootskaalse oorplanting by Namakwa Sands. Herstel van biodiversiteit en veranderings in grondeienskappe 15 maande na proewe begin het, is vergelyk m.b.t. die toediening van bogrond, besproeiing, oorplanting en onbehandelde oorblywende sand. Besproeiing kan biodiversiteit en digtheid van saailinge verminder. Vyvtien maande na opvulling en die toediening van bogrond, het kalium, natrium en kalsium teruggekeer na vlakke in onversteurde grond. Magnesium vlakke was nog altyd laer as dié voordat mynaktiwiteite aangevang is. Terugplasing van sand en toediening van bogrond mag die vestiging en rehabilitasie van plante bespoedig. Weerstand vermeerder met tyd wat 'n verlaaging in vry soute en soutagtigheid in die grond wat gebruik is vir rehabilitasie aantoon. Fosfor het nie teruggekeer tot vlakke van voorheen nie en vlakke van koolstofhet na 15 maande verlaag gebly, en kan die potential tot rehabilitasie belemmer. Elke rehabilitasie tegniek wat die myn gebruik bring kostes sowel as voordele mee. Om restorasie pogings te laat slaag moet insigte vanaf ekologie en ekonomie saam ingespan word. 'n Oorsig van waardasie sisteme toon dat Afslag Kontant Vloei Tegnieke geskik is vir die evaluasie van rehabilitasie programme.

The asbestos mining industry has left a legacy of pollution that continues to poison former mining areas and surrounding land – posing a significant health risk to local communities. The rehabilitation of sites disturbed by mining activities, aims to negate the adverse effects associated with these post-mining landscapes and to achieve the return of a disturbed site to a degree of its former state or to a sustainable usable condition. In order to assist the effective rehabilitation of derelict and ownerless asbestos mines it was critical to develop a scientific database to indicate the status of rehabilitation at specific sites. The Rehabilitation Prioritisation Index (RPI) was developed in 2007 to indicate the sequence for rehabilitation of asbestos pollution by quantifying the risk associated with a specific pollution site. The use of the RPI has been implemented by the South African Department of Minerals and Energy as part of an integrated approach towards the rehabilitation of the asbestos legacies of the past. In this study, a multidisciplinary approach was applied to sites in three provinces as identified in the RPI, to facilitate the development of the Rehabilitation Monitoring Index (RMI). It is envisioned that this index, as part of a larger monitoring database, would assist in the successful monitoring and long-term rehabilitation of asbestos mines. During the monitoring process, the most prominent aspects governing the rehabilitation process were identified from comprehensive assessments of quantitative and qualitative data. Quantitative parameters included cover depth, physical and chemical soil properties, soil microbial activity, vegetation properties and small mammal surveys. Qualitative data included the footprint area, land use, erosion or flood damage, secondary pollution and water control structure damage. From the quantitative data, those parameters which had the greatest influence on the rehabilitation process were identified. In order of most to least important these groups were analysed by multivariate statistical ordination and classified into four groups: success parameters > essentials to be addressed > reasons for failure > non-distinguishable entities. The qualitative data indicated that the Limpopo Province was in the highest state of degradation after rehabilitation and that site history plays an important role in rehabilitation planning. Quantitative and qualitative parameters were assessed for all sites and applied in the RMI as weighted factors from which the rehabilitation status of a specific site can be calculated. Qualitative data was given a weight of 25% and quantitative data a weight of 75%. RMI values were calculated for each parameter and sites were distributed across a range which classifies the sites according to their rehabilitation status. Once again the Limpopo Province was identified as the province with the least successful rehabilitation. The results from this investigation show that a multidisciplinary approach is a step in the right direction for the successful monitoring of rehabilitated post-mining sites such as asbestos mines. It is however necessary that the RMI must be validated and the weights allocated to qualitative parameters must be reconsidered for the future development of this tool. While the RPI and RMI cannot be compared directly, it might be of great revelation to reassess the RPI values of all the sites after rehabilitation and compare this data to the RMI values.
Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2010.

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. [127]-145).
As a culture, we have the capacity to lead creative lives. Part of that capacity lies in how something like music can touch on just about every aspect of human thinking and experience. If music is such a pervasive phenomenon, what does it mean for the way we consider our lives in health? There are three problems with connecting the richness of music to scientifically valid clinical interventions. First, it is unclear how to provide access to something as seemingly complex as music to a diverse group of subjects with various cognitive and physical deficits. Second, it is necessary to quantify what takes place in music interactions so that causality can be attributed to what is unique to the music experience compared to motivation or attention. Finally, one must provide the structure to facilitate clinical change without losing the communicative and expressive power of music. This thesis will demonstrate how new music technologies are the ideal interfaces to address the issues of scale, assessment, and structured intervention that plague the ability to introduce creative work into healthcare environments. Additionally, we describe the first neural interface for multisensory-based physical rehabilitation, with implications for new interventions in diverse settings. This thesis demonstrates the design and implementation of devices that structure music interaction from the neural basis of rehabilitation. At the conclusion of this research, it is possible to envision an area where users are empowered during scientifically based creative tasks to compose neurological change.
by Adam Boulanger.
Ph.D.

Stroke is a leading cause of disability for adults. Several studies confirm cognitive impairment in persons following stroke. Every stroke patient should have rapid access to cognitive screening and evaluation. In this study, Rasch analysis was used to determine the suitability of the telephone version of the Mini-Mental State Examination (MMSE) in screening for cognitive impairment in persons with stroke. The specific objectives were to determine the range of difficulty represented by the items of the telephone version of the MMSE, to identify the hierarchy of item difficulty and to compare the French and English versions of the test. Rasch analysis was conducted on data obtained from 267 persons with first-ever stroke who completed the telephone version of the MMSE at 1 month post stroke. Results indicated that the telephone version of the MMSE did not target the full range of the persons' cognitive ability, especially for those with 'higher' cognitive ability. The item difficulty ranged from (-3.258 to 2.585 logits), and the average person mean (2.351 logits) was greater than the average item mean set at 0. The test was easy for most persons; the majority were situated above the mean item difficulty. Fit of the items to the Rasch model is discussed with alternate scoring methods suggested.

The relationship between vegetation change and rehabilitation management is investigated at a severely degraded cut-over lowland raised mire on the Wales/England border, managed by Natural England and The Countryside Council for Wales. Positive responses are confirmed 11 years after rehabilitation commenced, identifying trends towards raised mire as well as bog pool vegetation and water table thresholds associated with these trends have been established. A landscape-scale vegetation survey was carried out three times over 9 years. Species abundance was correlated with average seasonal water table height, time since rehabilitation, cutting type and survey year. Key species maps for the time series confirmed positive vegetation response, but slower than stipulated in the site management plan. There was a clear increase in the target peat-forming species (Sphagnum cuspidatum, Eriophorum angustifolium and E. vaginatum) as a direct response to rehabilitation and correlating positively with a high water table. Permanent quadrat vegetation monitoring was carried out three times at five-year intervals. Uncut areas and areas of recent commercial cuttings were rehabilitated earliest having significant increases in target mire species without the loss of other mire species from excess inundation. In the recent commercial cutting areas, a successional trend was identified, from a low water table to a fluctuating water table characterised by Molinia caerulea-rich vegetation, followed by a transition to stable, inundated conditions supporting Sphagnum cuspidatum/Eriophorum spp pool vegetation. A second successional trend, associated with the achievement of a near-surface, stable water table, saw the development of raised mire vegetation including Sphagna other than S. cuspidatum. This latter trend was primarily found in the uncut areas of the site but was also found to a lesser extent in recently cut-over areas where it was preceded by a fluctuating water table with a Calluna vulgaris- Molinia caerulea vegetation. A new survey related water table residence time calculated from hydrology data with vegetation for each quadrat. Analysis identified a mire pool vegetation type correlated with shallow, above surface flooding. A diverse mire vegetation type was also found which correlated with the water table staying within the upper 10cm of peat. The minimum threshold for establishment of Sphagnum species was found to be an average water table level within the range of 5.1 to 10cm below the peat surface. Higher cover of Sphagnum species was related to shallow flooding – suggesting that these conditions would be most efficient in re-establishing mire vegetation. 3 A base-line vegetation monitoring survey on an area immediately following deforestation and damming identified a subtle but positive response of the mire vegetation to management within one year.

Presence of the Dark Triad traits of Machiavellianism, narcissism, and psychopathy in the workplace, especially among managers, has received increased attention due to the implications for organizations. One way to influence behavior in business organizations is through controlled interventions to change individual mind-sets. A review of the extant literature indicated that the relationship between Dark Triad traits and mind-set had not been sufficiently examined. A quantitative study was conducted to examine whether a manager's Dark Triad traits predict their mindset. To explore this relationship, a sample of 153 managers' responses was collected online. The Short Dark Triad measure was used to assess participants' Machiavellianism, narcissism, and psychopathy and the Implicit Theory Measure was used to assess mind-set. Regression showed that only Machiavellianism predicts mind-set, accounting for 7% of the variance in mind-set as the criterion variable. The findings indicate that the relationship between Dark Triad traits and mind-set is weaker than a review of the extant psychological literature might suggest. Additionally, this study found that the Dark Triad traits are significantly negatively correlated with manager age, which might provide a new direction for further research. Further research on how and why Dark Triad traits tend to decline with age is recommended. The present study suggests that a better understanding of the relationship between the Dark Triad traits and mind-set and the knowledge that controlled interventions aimed at promoting a growth mind-set are most likely not a useful tool to mitigate the level of Dark Triad psychological traits of managers in business organizations.

Bioengineering
Ph.D.
Delivery of neurotrophins to the injury site via cellular transplants or viral vectors administration has previously been shown to promote recovery of locomotor behavior in the absence of locomotor training in adult spinalized animals. Viral vectors still pose clinical concerns associated to recombinant genetics and the lack of understanding of how they react with the human immune system. Delivery via graft of autologous fibroblast engineered to produce brain derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3) has been shown as a valuable method; however, the need for multiple invasive surgeries, along with the impossibility of delivering a controlled and constant dosage of protein are serious obstacles to obtaining approval by the FDA. The present study was aimed at evaluating the efficacy of BDNF delivered to the lumbar locomotor centers using a clinically translational delivery method at restoring stepping abilities in a large animal model of spinal cord injury. We wanted to evaluate if intrathecal delivery of BDNF to the lumbar spinal cord would promote a locomotor recovery as effective as delivery to the injury site, even at doses low enough not to trigger the side effects observed at high doses. A programmable and implantable mini-pump was used to intrathecally deliver a 50 ng/day dose of BDNF to the lumbar spinal cord for 35 days after spinal thoracic transection. Kinematic evaluation was conducted before, 3 and 5 weeks after injury/pump implant. Ground reaction forces (GRFs) analysis was performed 5 weeks after injury to evaluate the animals’ ability to weight support during locomotion and standing trials. Results showed that treated cats were capable of executing weight-bearing plantar stepping at all velocities tested (0.3-0.8 m/s). Control cats did not recover stepping ability, especially at higher velocities, and dragged their hind paws on the treadmill. We were also interested in measuring the extent of BDNF diffusion within the lumbar area of the spinal cord and the potential damage to the cord caused by catheter insertion. Immunohistological evaluation showed higher BDNF expression in the dorsal root ganglions, with BDNF Immuno-Histo Chemistry (IHC) extending from L3 to L7 in all treated cats. BDNF was also found within multiple cells of the grey matter, although the levels were not significantly higher than background density. Glial fibrillary acidic protein (GFAP) stain was used to measure the immunohistological reaction of the spinal cord to the implanted catheter, and to establish the safety of the delivery method. Gross examination of the spinal cord post-mortem revealed no damage to the cord or the roots with minimal encapsulation of the catheter/pump. Minimal tissue inflammation was revealed by the GFAP stain, underlying the safety of our method. We also wanted to investigate and characterize changes in the locomotor circuitry induced by BDNF delivery. Comparison of multiunit activity in the lumbar area between BDNF treated and non-treated cats allows a better understanding of the mechanism of action of BDNF on the spinal interneurons. This was accomplished by extracellularly recording lumbar interneuronal firing during air-stepping in a 5 weeks post-injury terminal experiment. The cord was exposed at the lumbar level between the L3 and L7 spinal segments. In-vivo recordings of spinal extracellular signals were conducted using two 64 channels microelectrode arrays inserted at the dorsal root entry zone to depths of ~3000µm and ~1500µm. The ability to record simultaneous activity of multiple single neurons made it possible to study the extent to which spiking activity in a given neuron is related to concurrent ensemble spiking activity. A point process generalized linear model (PP-GLM) approach was used to assess the strength of the connections between spike trains. Interneurons activity was assessed in terms of average firing rate, signal-to-noise ratio (SNR), and number of active units per trial. Although BDNF infusion in the lumbar segments did not show significant effect on strengthening synaptic connections, we did find greater multiunit activity in the treated animals, sign of a potential BDNF-induced increase in interneuronal activation, which could be likely involved in recovery of stepping ability after SCI. Together, findings from these aims demonstrated the therapeutic potential of intrathecal lumbar BDNF delivery in spinalized animals. Constant infusion of BDNF to the locomotor centers promotes locomotor recovery similar to training or delivery to the injury site via cellular transplants after complete SCI. Intrathecal delivery by an implantable/programmable pump is a safe and effective method for delivery of a controlled BDNF dosage; it poses minimal risks to the cord and is clinically usable. Lastly, this study confirmed the major involvement of BDNF in increasing the activity of the interneurons in the locomotor circuitry, opening the door to further investigating the mechanism through which neurotrophins induce recovery of locomotion.
Temple University--Theses

Adherence is considered a prerequisite for the success of exercise programs for musculoskeletal disorders. The negative effects of non-adherence to exercise recommendations impact the cost of care, and also treatment effectiveness, treatment duration, the therapeutic relationship, waiting times, the efficiency of personnel and use of equipment. Adherence to therapeutic exercise intervention is a multifaceted problem. The World Health Organization (WHO) established the multidimensional adherence model (MAM). The MAM describes five interactive dimensions (socioeconomic, healthcare team and system, condition-related, therapy-related, and patient-related factors) that have an effect on patient adherence. The first purpose of this dissertation was to explore the MAM dimension of condition-related factors to determine the Quick Disabilities of the Arm Shoulder and Hand (QDASH) minimal clinical important difference (MCID) for three distal upper extremity conditions. The second purpose was to explore the MAM dimension of personal factors to learn from individuals who expressed incongruence between their QDASH and GROC scores; how they described their perceived change in therapy. The third purpose was to explore the MAM dimension of therapy-related factors to examine the effect of patient-therapist collaborative goal setting on patient adherence to treatment and QDASH outcomes. Results demonstrated in the first study that diagnosis specific MCID’s differed from the global MCID using multiple diagnoses. In the second study results demonstrated that patients expect to have a dedicated therapist who they can trust to work collaboratively with them to establish goals and spend time with them to achieve these goals. In the third study, our first hypothesis was not supported for all three measures of adherence. The median for home exercise program diary adherence was found to trend towards significance by 8.7 percent favoring the experimental group Mann-Whitney U (p < .100). Our second hypothesis was not supported. The experimental group receiving collaborative goal setting intervention had similar QDASH mean change scores 45.9±27.6 compared to the control group 46.1±23.8, Mann-Whitney U (p < .859).