Дисертації з теми "Herbicides Environmental aspects Victoria"

In many countries around the world, municipal sewage and industrial wastewaters are typically treated, or sometimes only partially treated, prior to their discharge into surface waters. A major anionic surfactant, Linear Alkyl benzene Sulfonate (LAS), and a degraded product of a non-ionic surfactant, Nonylphenol (NP), are frequently found in municipal wastewaters. When wastewater containing such surfactants and their degraded products is used for irrigation, it can have an effect on the sorption/desorption and movement of pesticides in soils. Therefore, a lysimeter study was conducted, in summer 2004, to assess the effect of LAS and NP on the movement of agricultural herbicides through a sandy loam soil. The degradation of the herbicides was studied in lysimeters over a ninety-day period. Irrigation water with a concentration of 12 mg L -1 of LAS and NP was used to assess their effect on the leaching of atrazine, metolachlor, and metribuzin. Moreover, a laboratory sorption experiment was undertaken to estimate the partition coefficients (kd) of the three herbicides with water containing the same concentrations of LAS and NP. Irrigation water containing low concentrations of surfactants (LAS and NP) did not increase leaching of the three herbicides. Therefore, these results would reduce the concerns regarding pesticide leaching through sandy soil brought on by LAS and NP in wastewaters for irrigation, which is becoming more important due to increasing water scarcity in the dry climate regions of the world.
Beside the lysimeter study, mathematical models can be used effectively and economically in a very short period of time for simulating herbicide concentrations into soil. PESTFADE, a one dimensional transient flow model, was used, in this study, to simulate the fate of the three herbicides in sandy soils. Another model, Artificial Neural Network (ANN), was also used over mathematical modeling due to its faster execution period and less input parameter requirements, for predicting the concentrations of the three herbicides in a sandy loam soil. The predicted concentrations, from both models were compared with the experimental results from the lysimeter study. Although slight overestimations and underestimations were observed, both models simulated herbicide concentrations in the soil profile satisfactorily.

Although the use of pesticides is necessary to meet the socio-economic needs of many developing countries, especially in Africa, side effects of these bio-active chemicals have contributed to contaminating aquatic and terrestrial ecosystems. Environmental water quality degradation by pesticides interferes with ecosystem health and poses numerous risks to aquatic life. In South Africa, glyphosate-based herbicides are frequently used to control weeds and invading alien plants, but ultimately end up in freshwater ecosystems. However, there are no South African-based environmental water quality management strategies to regulate these bio-active chemicals. Therefore, this study sought to provide a sound scientific background for the environmental water quality management of glyphosate-based herbicides in South Africa, by conducting both laboratory and field investigations. In the laboratory investigations, aquatic ecotoxicological methods were used to evaluate responses of the freshwater aquatic shrimp Caridina nilotica exposed to Roundup® at different biological system scales, and the responses of multiple South African aquatic species exposed to Roundup® through species sensitivity distribution (SSD). In the field investigations, the effect of Kilo Max WSG on the physicochemical and biological conditions of three selected sites in the Swartkops River before and after a spray episode by Working for Water were evaluated through biomonitoring, using the South African Scoring System version 5 (SASS5) as a sampling protocol. Both Roundup® and Kilo Max WSG are glyphosate-based herbicides. All the data were subjected to relevant statistical analyses. Findings of this study revealed that Roundup® elicited responses at different biological system scales in C. nilotica, while SSD estimates were used to derive proposed water quality guidelines for glyphosate-based herbicides in South Africa. The biomonitoring revealed that using glyphosate-based herbicides to control water hyacinth within the Swartkops River had a negligible impact on the physicochemical and biological conditions. Based on these findings, a conceptual framework that can be used for the integrated environmental water quality management of glyphosate-based herbicides in South Africa was developed as part of integrated water resource management (IWRM). The combined data sets contribute to a sound scientific basis for the environmental water quality management of glyphosate-based herbicides in South Africa.

The state of the environment is increasingly present as an urgent concern for contemporary political, social, cultural and physical life. Yet the roles of the mass media (radio, television and newspapers) in shaping and influencing crucial public awareness, debates and environmental decision-making remain inadequately understood. Positioned as a critical studies inquiry into media representations and audience reception, this study forms part of a wider project amongst media scholars and culture critics on the relationship between media textual production and consumption. It explores how one radio station in Uganda, Central Broadcasting Service (CBS) radio, represents and constructs the environmental crises faced by Lake Victoria, especially pollution and overfishing. The focus is on the Victoria Voice radio documentaries aired on CBS radio in the year 2005. The study further explores how three lakeside communities negotiate these issues as radio broadcasts. It recognises that while the mass media contribute significantly to creating public awareness about such social concerns, their likelihood of having a direct and predictable impact on social behaviour is slight. The context and the lived experiences at the reception stage where the decisions are made on whether to adopt an innovation are ultimately the factors which impact on how they are negotiated. The thesis is informed by the theoretical and analytical framework of Cultural Studies as well as the Participatory Approach to Communication for Development perspectives. The study is specifically informed by the theories of ‘discourse’ (Foucault, 1980a, 1981) and the ‘circuit of culture’ (du Gay et al., 1997 and Johnson, 1987) and these provided the conceptual framework for investigating the representations, the production and the consumption of media texts. Predominantly qualitative methods have been employed in data collection and analysis. In the first place, a Critical Discourse Analysis (CDA) (Fairclough, 1995a, 1995c) of the radio texts has interrogated the discourses and discursive practices of CBS’ Victoria Voice environmental radio programmes in order to consider its representations of particular issues and consequently the discourses it privileged. Qualitative methods of participant observation, in-depth interviews and focus group discussions were deployed to investigate the negotiation of the texts by the lakeside communities. This research establishes that the Victoria Voice radio texts foreground three contesting types of discourses: the discourse of basic economic survival and livelihoods is articulated largely by the ordinary people, the lakeside communities; the discourse of sustainable development, particularly the protection and sustainability of Lake Victoria, by scientists and environmental experts; and the discourse of modernisation and corporate investment by politicians and/or policy makers and industrialists. The texts, to a large degree, reaffirm the hegemonic relations of power in Ugandan society, and thus contribute to the maintenance of the status quo. The selection of an elite category of informers (scientists, experts, politicians, policy makers) serves to marginalise the less powerful ordinary people (the fisher folk, farmers and other eyewitnesses). The construction of the elite as active and speaking subjects within the various debates introduced in these programmes, for example, works both to obscure and endorse the unequal power relations. At the reception side, while the lakeside communities attest to the relevance of the programmes in providing information on the issues concerning Lake Victoria and other aspects of their livelihood, they also recognise the power relations that underpin the sets of representations. Amongst these sets is government’s complicity with industry, in line with their economic policies and the global capitalist economy, while espousing the rhetoric of nature conservation. The study argues that sustainable solutions for the crises on Lake Victoria should take into account the socio-historical and cultural contexts of the lakeside communities. For the Ugandan media, particularly radio, there is a need to rethink the nature of the coverage, which tends to neglect the contextual factors, such as local socio-economic and cultural factors within which environmental issues and problems occur and which, as this thesis establishes, greatly influences the way people make sense of environmental issues and problems. I posit that the Participatory Approach that seeks to address the communities’ most pressing concerns should be adopted – to include more of the communities’ voices and involve them in the production of radio programmes.

A leaching study was undertaken with $ sp{14}$C radio-labelled atrazine in long, intact, soil columns to investigate the fate and transport of atrazine in a Quebec sandy loam soil and to test two contaminant transport models, namely PRZM and LEACHMP.
Results indicated a large variation in atrazine concentration. The maximum levels in the leachate of the soil columns ranged from 0 to 11.2 $ mu$g/L. Deisopropyl-atrazine, the principal metabolite in the soil columns, was detected near the soil surface and did not leach beyond 15 cm depth. The adsorptive and desorptive capacity of atrazine in the soil columns was mainly attributed to organic matter and moisture content.
LEACHMP was found to be superior in predicting hydrologic characteristics in the soil columns as compared to PRZM which required calibration. Both models underestimated levels of atrazine near the soil surface and in the leachate (115 cm depth). The results from first and second order analysis for PRZM and LEACHMP showed considerable uncertainty in atrazine fate and transport. First and second order analyses were found to be useful tools in indicating where efforts to reduce uncertainty can best be directed.

A field study was undertaken during the growing seasons of 1988 and 1989 to investigate leaching characteristics of metolachlor, atrazine and two atrazine metabolites in two agricultural soils of Quebec, namely a sand and a loam field. In both years, atrazine was detected in higher levels in the groundwater of the loam field than of the sand field. Deethylatrazine was the only metabolite found in any significant quantity in soil in 1988 and in groundwater in 1989. Deisopropylatrazine was detected in groundwater at the beginning and at the end of the 1988 season and levels were similar in both fields. Metolach or was never detected in groundwater.
GLEAMS predictions favourably compared to field results at the 0-20 cm depth in both years. Half-life, however, had to be reduced by half in 1989 since higher temperature had increased dissipation. GLEAMS has not predicted leaching past 20 cm in either field in 1988 and 1989. During a dry summer, such as 1988 and 1989, leaching is mostly due to macropore flow and desorption of residues, two processes which are difficult to predict with existing models.

Subirrigation systems are generally used in humid areas to provide suitable moisture conditions for plant growth. These systems can also be used to reduce pesticide loadings from agricultural lands, since they tend to keep the discharging waters within farm boundaries for extended periods of time. This allows for greater pesticide microbial and chemical degradation.
A three-year field lysimeter study was initiated to investigate the role of subirrigation systems in reducing the risk of water pollution from the three most commonly used herbicides in Quebec, namely atrazine (2-chloro-4[ethylamino]-6[isopropylamino]-1,3,5-triazine), metribuzin (4-am ino-6(1,1-di meth yl eth yl)-3-(meth yl thio)-1,2,4-tria zin-5(4H)-one), and meto lach lor (2-chlo ro-N-(2-eth yl-6-methyl phen yl)-N-(2-meth oxy-1-meth yl eth yl)acet amide). Eighteen PVC lysimeters, 1 m tall x 0.45 m diameter, were packed with a sandy soil. Three water table management treatments, i.e. two subirrigation treatments with constant water table depths of 0.4 and 0.8 m, respectively, and a free drainage treatment in a completely randomized design with three replicates were used. Grain corn (Zea mays L.) and potatoes (Solanum tuberosum L.) were grown on lysimeters, and herbicides were applied each year at the locally recommended rates at the beginning of each summer. Soil and water samples were collected at different time intervals after each natural or simulated rainfall event. Herbicides were extracted from soil and water samples and were analyzed using Gas Chromatography.
From the three years results (1993--1995), it has been concluded that all three herbicides were quite mobile in this sandy soil, as they leached to the 0.85 m depth below the soil surface quite early in the growing season. This suggests that if the drainage effluent or seeping waters from sandy soils of agricultural lands in southern Quebec drain freely, they may be considered to be a serious non-point source of pollution to the water bodies. The results have also shown that herbicide concentration decreased with soil depth as well as with time, meaning that the higher herbicide residues were found at top layers, and soon after the herbicide application. The herbicide mass balance study revealed that when the drainage effluent was kept within the lysimeters under the subirrigation setup, there was a statistically significant reduction of atrazine and metribuzin residues (shorter half lives) in the adsorbed and liquid phases. However, the reduction in metolachlor concentration under the subirrigation system was not statistically significant. These findings suggest that subirrigation, combined with certain herbicides can significantly reduce the herbicide loadings from corn and potato farms in southwestern Quebec, and become environmentally beneficial.
A computer simulation model (PRZM2), was used to simulate atrazine, metribuzin, and metolachlor leaching in the lysimeters, under subsurface drainage conditions. The simulated values for all three chemicals in most of the cases followed the leaching pattern of observed data. But the model either under- or over-estimated the herbicide concentrations in the soil. This could have been caused by simplistic instantaneous linear adsorption/desorption of herbicides, and inadequacy of conventional Darcian approach for the treatment of matrix flow.

Thesis (MScAgric)--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: The aim of this study was to determine the effect of a grass herbicide, a broadleaf herbicide with some grass control capabilities, method of tillage (tine and no-tillage) at planting of wheat as well as different medic cultivars on the regeneration, dry matter (OM) production and quality of a medic pasture. The trial was conducted at Langgewens experimental farm in the Swartland wheat producing area. Nine medic cultivars of three different species were evaluated after being sprayed with either haloxyfop-R-methyl (HAL) ester or imazamox (IMI) and subjected to either a tine tillage or a no tillage treatment at planting of wheat. Soil samples were taken during January 2000 to determine the size of the medic and weed seedbank as well as the degree of dormancy in the medic seeds, while OM samples were taken throughout the growing season to determine the OM production of the different medic cultivars and weed species. OM samples taken during October 1998 on the same pasture, were used to determine the crude protein (CP) and neutral detergent fibre (NOF) content of the pasture. The samples were subjected to in vitro digestion and the digestibility of pasture CP (OCP), NOF(ONOF) and DM (DOM)were determined. Results showed that seedling establishment differed between cultivars used, herbicide treatments applied as well as the crop stage in the rotation. The cultivars produced more seedlings where IMI was applied compared to HAL as well as where the area consisted of two year pasture compared to one year pasture (1998) and one year wheat (1999). After a year of pasture and a year of wheat, cultivars Sephi and Paraggio produced the most seedlings, while Caliph and Orion produced the least. Caliph however, showed a very high degree of seed dormancy while Orion's low seedling establishment was due to its sensitivity to the IMI herbicide used. Little difference was found between the nine cultivars early in the season (July - August) with regard to cumulative OM production, except for Orion, whose growth was severely damaged by the IMI treatment. At the end of the growing season (October), the cultivar Caliph's cumulative OM production (2010.1 kg/ha) was significantly higher than all the other cultivars, except for Parabinga (1053. 4 kg/ha). Oifferent pasture samples, of which the botanical composition was known, was analysed for CP, NOF, OOM, OCP and ONOF. There was no significant difference in pasture composition during 1998 but variation in the pasture composition did however cause the IMI treatment, compared to the HAL treatment, to have a lower ONOFand OOMcontent. A modelling procedure was used to predict the pasture quality parameters (CP, NOF, OOM,OCP and ONOF) from the pasture composition (medic hay, medic pods, grassy and broadleaf weeds). This prediction of CP, NOF, OOM, ONOF and OCP from the pasture components had a relative low accuracy (49 -74.1 %) and a further refinement of this model for possible use on farms in order to improve grazing management and animal production is advised. In conclusion it could be said that broadleaf weed control caused a definite increase in medic seed and OMproduction, but Orion should not be used with an IMI herbicide. All the cultivars, except for Orion, produced enough seedlings up to the second year to ensure sustainability of the medic pasture. All the cultivars, except for Orion, produced a sufficient amount of OM early in the growing season. Caliph however, produced by far the most OM later in the growing season. A reduction of broadleaf weeds and medic pods will increase the digestibility of NOFand OMand therefore increase the quality of the pasture. Pods however are an important part of summer forage and the aim should therefore rather be to reduce the number of broadleaf weeds in the pasture.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van 'n gras en breëblaar onkruiddoder (wat sekere grasse beheer), metode van bewerking tydens die saai van koring asook nege verskillende medic kultivars op die regenerasie, droë materiaal produksie en kwaliteit van medic weidings te bepaal. Die proef is gedoen op Langgewens proefplaas wat geleë is in die Swartland koring produserende gebied. Nege medic kultivars is geëvalueer nadat die weiding met of haloxyfop-R-metiel ester (HAL) of imazamox (IMI) onkruiddoders gespuit is en onderwerp is aan of 'n vlak tand of geen bewerking tydens die saai van koring. Grondmonsters is geneem in Januarie 2000 om die grootte van die medic en onkruid saadbank asook om die graad van dormansie in die verskillende medic kultivars se sade te bepaal. Droë materiaal monsters is gedurende die 2000 groeiseisoen geneem om die droë materiaal produksie van die verskillende medic kultivars asook onkruid spesies te bepaal. Droë materiaal monsters is gedurende Oktober 1998 geneem en gebruik om die ruproteïn (CP) en neutraaloplosbare vesel (NDF) inhoud van die weiding te bepaal. Die monsters is in vitro verteer en die verteerbaarheid van CP (OCP), NDF (ONOF) en droë materiaal (DOM) is bepaal. Resultate wys dat saailing vestiging verskil tussen die verskillende kultivars wat gebruik is, verskillende onkruiddoder behandelings asook die stadium van die weidings/koring. Die kultivars het meer geproduseer waar die weiding met IMI behandel is in vergelyking met waar HAL toegedien is, asook waar koring nog nie gesaai is nie. Na 'n jaar van weiding en 'n jaar van koring, het die kultivars Sephi en Paraggio die meeste saailinge, en Caliph en Orion die minste saailinge gehad. Caliph het egter 'n hoë graad van dormansie in sy saad getoon, terwyl die swak vestiging van Orion die gevolg is van die kultivar se hoë sensitiwiteit teenoor IMI. Min verskil is gevind tussen die nege kultivars, vroeg in die groei seisoen (Julie - Augustus), wat kumulatiewe droë materiaal produksie betref, behalwe vir Orion wat erg beskadig is deur die IMI behandeling. Aan die einde van die groeiseisoen (Oktober 2000) was die kumulatiewe droë materiaal produksie van die kultivar Caliph (2010.1 kg/ha) betekenisvol hoër as al die ander kultivars behalwe vir Parabinga (1053.4 kg/ha). Weidingsmonsters, waarvan die botaniese samestelling bekend was, is ontleed vir CP, NDF, DDM, DCP en DNDF. Daar is geen betekenisvolle verskille gevind in die botaniese samestelling van die weidingmonsters geneem in 1998 nie,maar die variasie in botaniese samestelling het veroorsaak dat IMI in vergelyking met HAL 'n laer DNDF and DDM inhoud het. 'n Model is opgestel wat die weidingskomponente (medic hooi, medic peule, gras en breëblaar onkruide) gebruik om die kwaliteits parameters (CP, NDF, DDM, DCP en DNDF) van die weiding te skat. Hierdie skatting van CP, NDF, DDM, DCP en DNDF deur van die weidingskomponente gebruik te maak het 'n relatiewe lae akuraatheid gehad (49 -74.1 %) en verdere verfyning van hierdie model vir moontlike gebruik op plase, ten einde weidings bestuur en diere produksie te verbeter, word voorgestel. Die gevolgtrekking kan gemaak word dat breëblaar onkruidbeheer 'n definitiewe verbetering in die medic saailing en droë materiaal produksie van die medies te weeg gebring het, maar die kultivar Orion behoort nie saam met 'n IMI gebruik te word nie. AI die getoetste kultivars, behalwe Orion, het voldoende saad oorlewing vertoon tot en met die tweede jaar van die rotasie om lewensvatbaarheid van die sisteem te verseker en alle kultivars, behalwe Orion, het voldoende droë materiaal produseer vroeg in die groeiseisoen. Caliph het egter laat in die groeiseisoen by verre die meeste droë materiaal geproduseer. 'n Vermindering in die hoeveelheid breëblaar onkruide en peule in die weiding sal tot 'n verhoging in die verteerbaarheid van NDF en DM lei en dus 'n verhoging in die kwaliteit van die weiding tot gevolg hê. Peule is egter 'n belangrike bron van voedsel aan weidende diere gedurende droë somermaande en die verbetering van weidings moet eerder gedoen word deur te poog om breëblaar onkruide te beheer.

A variety of conservation trends have gained and lost favor throughout the years in agriculture, with U.S. Farm Bills often influencing what conservation practices are implemented by farming communities throughout the U.S. This dissertation focuses on the unintended consequences of conservation management practices in the Fifteenmile Watershed of Wasco County, Oregon. Specifically, I seek to address how farmer enrollment in various conservation techniques, loosely defined as no-till agriculture, has affected soil and water quality through the increased use of herbicide, and subsequently rendered ecological and human health vulnerable. Using a critical physical geography framework, I address both the biophysical factors and social structures that have co-produced changes in soil and water quality in the study area of this research through intensive physical field data collection, spatial analysis, social surveys, and interviews. I also demonstrate how three neoliberal sets of processes: market-friendly reregulation; state rollback and deregulation; and the creation of self-sufficient individuals and communities, have transformed the human socio-environmental relationship to agriculture. These processes have had significant effects on the policies governing how soil and water quality are managed on both a state and national level, and have created a dependence on enrollment in conservation practices that may ultimately prove counterproductive for long term goals of environmental protection and sustainability.

The herbicide, Dacthal (dimethyl 2,3,5,6,-tetrachloroterephthalate) is hydrolyzed to give the corresponding diacid and this derivative is a common contaminant in ground water. In the Ontario region of eastern Oregon the use of this herbicide on onions has resulted in the contamination of an aquifer with this derivative. Since movement to groundwater is determined by the hydrolysis of the parent compound to a more soluble derivative. The rate at which this hydrolysis reaction occurs and the stability of the metabolite must be defined. These parameters have been determined using soils from Ontario in which onions had been raised. At room temperature and 50% field capacity, the parent was hydrolyzed rapidly (half-life 16 days) to the diacid derivative. An increase of the incubation temperature to 38°C reduced the hydrolysis rate significantly (half-life 86.8 days). It is assumed that this response reflects reduced microbial activity at the higher temperature. At both temperatures only small amounts of the monoacid intermediate were detected suggesting that the Dacthal monoacid was being hydrolyzed at a faster rate than the parent. It was established that at room temperature, the half-life of the monoacid was only 2.8 days. Over the 300 days the experiments were carried out, little if any degradation of the diacid metabolite could be detected. There was virtually no degradation of the parent over a 60 day period in sterilized soil, suggesting that microbial activity is primarily responsible for this step. By contract, the monoacid was hydrolyzed at comparable rates in sterilized and nonsterilized soil. This study explains why the Dacthal metabolite is a common contaminant in groundwater. The parent is rapidly hydrolyzed to the diacid which is much more water soluble. More important, however, is the persistence of the diacid metabolite in the environment.
Graduation date: 1992

by Tsui Tsz Ki, Martin.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2002.
Includes bibliographical references (leaves 119-138).
Abstracts in English and Chinese.
Acknowledgements --- p.I
Abstract --- p.III
Table of Contents --- p.VII
List of Tables --- p.XII
List of Figures --- p.XIV
Abbreviations --- p.XVI
Chapter Chapter 1 --- General Introduction
Chapter 1.1 --- Research Background --- p.1
Chapter 1.1.1 --- General description of glyphosate --- p.1
Chapter 1.1.2 --- Physical and chemical properties of glyphosate --- p.2
Chapter 1.1.3 --- Commercial formulations based on glyphosate --- p.3
Chapter 1.1.4 --- Overview of ecotoxicological studies of glyphosate-based formulations --- p.4
Chapter 1.1.4.1 --- Aquatic toxicity of glyphosate-based formulations --- p.4
Chapter 1.1.4.2 --- Environmental fate of glyphosate-based formulations in waters --- p.12
Chapter 1.1.5 --- Interaction of glyphosate and other substances --- p.14
Chapter 1.2 --- Overview of Aquatic and Sediment Toxicology --- p.16
Chapter 1.2.1 --- Aquatic toxicology --- p.16
Chapter 1.2.2 --- Introduction to sediment toxicology --- p.19
Chapter 1.3 --- "Significance, Outline and Objectives of the Present Study" --- p.20
Chapter 1.3.1 --- Significance of the research --- p.20
Chapter 1.3.2 --- Thesis outlines and research objectives --- p.22
Chapter Chapter 2 --- Aquatic Toxicity of Glyphosate-based Herbicides to Different Organisms and the Effects of Environmental Factors
Chapter 2.1 --- Introduction --- p.25
Chapter 2.2 --- Materials and Methods --- p.26
Chapter 2.2.1 --- Test organisms --- p.26
Chapter 2.2.2 --- Test chemicals --- p.27
Chapter 2.2.3 --- Comparison between different organisms --- p.27
Chapter 2.2.4 --- Environmental factors in modifying Roundup® toxicity --- p.30
Chapter 2.2.5 --- Analysis of glyphosate concentration --- p.31
Chapter 2.2.6 --- Validity of tests and statistical analyses --- p.32
Chapter 2.3 --- Results --- p.32
Chapter 2.3.1 --- Comparison between different groups of organisms --- p.32
Chapter 2.3.2 --- Environmental factors in modifying Roundup® toxicity to C.dubia --- p.35
Chapter 2.4 --- Discussion --- p.36
Chapter 2.4.1 --- Toxicity of glyphosate to photo synthetic organisms --- p.36
Chapter 2.4.2 --- pH-associated toxicity of glyphosate --- p.37
Chapter 2.4.3 --- High potency of surfactant --- p.38
Chapter 2.4.4 --- Effects of environmental factors on Roundup® toxicity --- p.38
Chapter 2.5 --- Conclusions --- p.39
Chapter Chapter 3 --- "Toxicity of Rodeo®, Roundup® Biactive and Roundup® to Water-column and Benthic Organisms and the Effect of Organic Carbon on Sediment Toxicity"
Chapter 3.1 --- Introduction --- p.41
Chapter 3.2 --- Materials and Methods --- p.43
Chapter 3.2.1 --- Test chemicals --- p.43
Chapter 3.2.2 --- Test organisms --- p.43
Chapter 3.2.3 --- Toxicities to water-column and benthic organisms --- p.44
Chapter 3.2.4 --- Effect of sediment organic carbon --- p.45
Chapter 3.2.5 --- Statistical analyses --- p.48
Chapter 3.3 --- Results --- p.48
Chapter 3.3.1 --- Toxicities to water-column and benthic organisms --- p.48
Chapter 3.3.2 --- Effect of sediment organic carbon --- p.49
Chapter 3.4 --- Discussion --- p.54
Chapter 3.4.1 --- Different sensitivities between water-column and bethic animals --- p.54
Chapter 3.4.2 --- Relative toxicities of three herbicides --- p.56
Chapter 3.4.3 --- Route of exposure of herbicides in sediment to organisms --- p.57
Chapter 3.4.4 --- Sediment toxicity of glyphosate-based formulations --- p.58
Chapter 3.4.5 --- Effect of organic carbon on partitioning and toxicity --- p.60
Chapter 3.5 --- Conclusions --- p.61
Chapter Chapter 4 --- Joint Toxicity of Glyphosate and Several Selected Environmental Pollutants to Ceriodaphnia dubia
Chapter 4.1 --- Introduction --- p.63
Chapter 4.2 --- Materials and Methods --- p.65
Chapter 4.2.1 --- Test organisms and toxicity tests --- p.65
Chapter 4.2.2 --- Test chemicals --- p.66
Chapter 4.2.3 --- Experiment I: Joint acute toxicity of Roundup® and nine toxicants --- p.66
Chapter 4.2.4 --- Experiment II： Effect of IPA salt of glyphosate alone at EEC on toxicities of heavy metals --- p.67
Chapter 4.2.5 --- Basic water properties and chemical analyses --- p.69
Chapter 4.2.6 --- Statistical analyses --- p.70
Chapter 4.3 --- Results --- p.70
Chapter 4.3.1 --- General conditions and recovery for spiked chemicals --- p.70
Chapter 4.3.2 --- Experiment I: Joint acute toxicity of Roundup® and nine toxicants --- p.71
Chapter 4.3.3 --- Experiment II: Effect of IPA salt of glyphosate alone at EEC on toxicities of heavy metals --- p.73
Chapter 4.4 --- Discussion --- p.75
Chapter 4.4.1 --- Interactions of Roundup® and other toxicants --- p.75
Chapter 4.4.2 --- Joint toxicity of dissimilar chemicals --- p.77
Chapter 4.4.3 --- Complexation of glyphosate with metals interactions between liquid/solid phases --- p.79
Chapter 4.5 --- Conclusions --- p.83
Chapter Chapter 5 --- Environmental Fate of Glyphosate and its Nontarget Impact: a Case Study in Hong Kong
Chapter 5.1 --- Introduction --- p.85
Chapter 5.2 --- Materials and Methods --- p.87
Chapter 5.2.1 --- Description of study sites --- p.87
Chapter 5.2.2 --- Physicochemical characteristics of different matrices --- p.88
Chapter 5.2.3 --- Continuous weather monitoring --- p.89
Chapter 5.2.4 --- Herbicide applications --- p.89
Chapter 5.2.5 --- Experimental designs --- p.90
Chapter 5.2.5.1 --- Estuarine enclosure experiment --- p.90
Chapter 5.2.5.2 --- Freshwater pond experiment --- p.92
Chapter 5.2.6 --- Schedule of sample collection and sample storage --- p.92
Chapter 5.2.7 --- Sample preparation --- p.94
Chapter 5.2.7.1 --- Water samples --- p.94
Chapter 5.2.7.2 --- Sediment samples --- p.94
Chapter 5.2.8 --- Sample determination --- p.95
Chapter 5.2.8.1 --- Pre-column derivatization --- p.95
Chapter 5.2.8.2 --- High performance liquid chromatography analyses --- p.95
Chapter 5.2.8.3 --- Calibration of glyphosate and AMPA --- p.95
Chapter 5.2.8.4 --- Recovery of glyphosate in spiked samples --- p.96
Chapter 5.2.9 --- Statistical analyses --- p.96
Chapter 5.3 --- Results --- p.96
Chapter 5.3.1 --- Site characteristics --- p.96
Chapter 5.3.2 --- Weather conditions during herbicide application --- p.99
Chapter 5.3.3 --- Chemical analyses --- p.100
Chapter 5.3.4 --- In-situ toxicity tests --- p.104
Chapter 5.4 --- Discussion --- p.106
Chapter 5.4.1 --- Site-specific factor affecting the environmental fate --- p.106
Chapter 5.4.1 --- Site-specific factor affecting the environmental fate of glyphosate --- p.106
Chapter 5.4.2 --- Glyphosate in water and sediment --- p.106
Chapter 5.4.3 --- Homogeneity of glyphosate in surface water and sediment --- p.109
Chapter 5.4.4 --- Effect of weather conditions on environmental fate of glyphosate --- p.109
Chapter 5.4.5 --- Biological impact of Roundup® --- p.110
Chapter 5.5 --- Conclusions --- p.112
Chapter Chapter 6 --- General Conclusions --- p.113
References --- p.119

Surface water quality of the Liverpool Plains (NSW), a series of floodplains comprising the floodplain of the Mooki River, is poor despite the introduction of conservation tillage that has reduced soil erosion and, with it, the transport of sediment, nutrients and chemicals to streams.The aim of this thesis was to provide a basis for recommending the possible wider use of biofilters, by determining their effectiveness in reducing pollutant (mainly atrazine) transport at multiple scales in the Liverpool Plains, quantifying the importance of relevant processes, including the capacity of soil biofilters to degrade the retained pollutants, and evaluating the effect of pollutants on the biofilter vegetation. These objectives were explored in two sub-catchments within the Liverpool Plains, namely Big Jacks Creek and the Blackville.Soils are predominantly vertosols that crack deeply on drying, resulting in initially high infiltration rates on wetting and high water holding capacity. Field monitoring revealed that biofilters such as grassed waterways, natural grasslands or vegetated filter strips (VFS) positioned at multiple catchment scales can significantly reduce pollutant concentrations in runoff. The use of biofilters is discussed, along with other best management practices that will be needed to manage pesticide loads both at source and in the transport pathway.
Doctor of Philosophy (PhD)

This thesis seeks to explain how site-scale design decisions can assist retention of rare plant communities concentrated in and near settled areas. To do so it focuses on a specific species and development context. Explanations are sought through examination of case studies of landuse developments in proximity to retained Garry oak plant communities located in the perimeter of Victoria, British Columbia. In the study region, exponential declines in species populations, health, and diversity of rare Garry oak ecosystems have been largely attributed to impacts from land-use developments. Over the past century, land-use developments have transformed the floral, spatial, structural and functional characteristics of the settled landscape. Isolated islands of imperiled plant associations remain on protected bioreserves: for recruitment and connectivity, these rare fauna rely on private-land greenways. Architectural teams have the potential to influence the decision-making processes that create ecologically-vital greenspace on private land, thereby enhancing survival for declining plant communities. Case-study evidence for the importance of land-use decisions on diminishing Garry oak meadow is gathered through vegetation surveys conducted on Garry oak meadow in proximity to six architectural projects on Victoria's western edge. Observed changes in growth extensions are then categorized in relation to human activities associated with built form, and correlated with principles from Landscape Ecology. An ARC of design strategies, developed in primary research by K. D. Rothley is adapted for architectural use as follows: firstly, AREA of a plant community is kept free of encroachment by the orderly frame established around vegetation; secondly, RARE SPECIES and habitat are identified with borders or signage; thirdly, CONNECTIVITY between retained landscapes is secured by siting roads and buildings to minimize ecosystem fragmentation. To effectively communicate preexisting landscape ecology principles, grouped under the ARC of strategies, illustrations and key-word phrases are developed. These principles, when integrated into architectural teams' structural knowledge, extend the architects' perceived role beyond aesthetics and economic efficiency. Enhancing habitat value through retention or restoration of rare ecosystems at the margins of suburban development, becomes an additional realm of influence for professional teams designing the spatial configurations of peri-urban landscapes.

Research Thesis  Submitted  in  Fulfilment  of  the  Requirements  for  the  Degree  of  Doctor  of   Philosophy  in  Economics, School of Economic & Business Sciences Faculty of Commerce, Law and Management University of Witwatersrand, Johannesburg, SA
The world is facing a sustainability crisis due to depletion and degradation of environmental and natural resources faster than they can be generated. Many of these resources are not partitioned by private property rights, and are held as state property, common property, or as open-access. Common Property Resources (CPRs) have two distinct attributes: (1) limited or nontrivial exclusion (it is difficult to exclude multiple individuals or users from appropriating from the resource) and (2) substractability (the resource features rivalry in consumption), meaning that appropriation by one reduces the overall resource availability and thus, subtracts from what can be appropriated by others. Examples include fisheries, grazing lands, irrigation systems, and ground water basins. Because no one has property rights or control over such resources, users of CPRs are frequently assumed to be caught in an inescapable dilemma - overexploitation of the resource. Thus, unlike the ‘invisible hand’ of Adam Smith in competitive markets, in the case of CPRs the self-interested behavior does not yield economic efficiency or optimal outcome or Pareto optimality. This study sought to understand the evolution of management dynamics and operation of governance structures developed by resource users and other stakeholders in three large scale CPRs in Kenya. The objectives are to (1) examine the evolution of management dynamics. (2) Examine the management model applied and its functioning. (3) Explore the governance structures and challenges of implementing them. (4) Explore critical variables related to user groups, institutional arrangements and external environment in the resource system. (5) Suggest measures to improve on the management and governance of the resource system. In addition, the study gives a comparative analysis of the management models applied in the three CPR systems. The general theoretical literature on CPRs has focused mainly on two basic but important conditions or categories. First, small scale communally owned and governed resources, in ii terms of the physical or geographical size of the resource system with well-defined boundaries. Secondly, group or users size, characterized by small numbers with similar identities and interests. This study therefore, contributes to literature by using large scale CPR case studies in terms of physical size of resource system and number of users and examining the evolution and dynamics in the management model and governance structures. A Qualitative Research (QR) methodology is adopted and analytical tools of institutional analysis and an empirical foundation based on field data applied. A survey research design is used. Both primary and secondary data was sourced and a pilot study was conducted to test reliability of research instruments. Data is documented, compiled and presented in form of tables, figures and general descriptions. Data analysis and synthesising is done by working through the data to arrive at a conclusion to answer the research questions and achieve the purpose of the study. The study findings show that management and governance issues in the three CPRs have evolved over time both in terms of the scale and involvement of other stakeholders in decision making process in the resource system. Specifically, the collaborations among state agencies, other stakeholders and resource users through their associations has enabled monitoring and enforcement not only be effective but also legitimate and consequently, lead to sustainable resource use. The management models used in the three CPR case studies are identified as the Partnership Fisheries Management (PFM) in Lake Victoria fishery, Participatory Irrigation Management (PIM) in Mwea Rice Irrigation Scheme and Holistic Management Framework (HMF) in Laikipia group grazing lands. The governance structures applied in the three CPRs are generally position, boundary, choice or authority, aggregation, information, payoff and scope rules. The degree of application of each set of rules however, depends on the nature of the resource system. They are designed, developed, implemented, monitored, enforced, sanctioned and arbitrated by the resource users, state lead agencies, departments and ministries iii and other stakeholders or actors. Each of these actors are involved in varying degrees in the various phases depending on their role and interest in the resource system. The management and governance structures can be strengthened and improved by enhancing certain administrative, health, safety, environmental issues and increased state support and involvement in the resource system. The co-management model design which is applied in the three CPRs yield various benefits to the resource-dependent community, public, state and resource system because it incorporates state and local (resource users) managers in decision making. However, the degree of participation of other stakeholders, challenges faced and other internal and external factors, depend on the nature of CPR, ownership and control of the CPR by resource users and the technical infrastructural investments required for the operation of the system. These results add to existing knowledge on Sustainable Development (SD) environment nexus by providing facts to multidisciplinary environmental and natural resources scholars regarding the dynamics of large scale CPR systems. Provide an in depth understanding of CPR management issues for the formulation of national strategies for SD, fisheries, Arid and Semi-Arid Lands (ASALs), and irrigation farming. Lastly, they provide ways of responding to increasing challenges of shared water resources (Lake Victoria) in addition to strengthening of relations within the East African Community (EAC). Key words: Actors, bio-physical and community attributes Common Property Resources, governance structures, institutions, large scale, management models, resource users, resource systems
GR2018

This study evaluated anticipated changes to quality of life (QoL) from a reduction in private vehicle use, and the impact of social normative information on willingness to change transportation behaviour. Staff and students at the University of Victoria completed transport journals for a month, and participants in the low or high social norm condition received divergent information about the percentage of others who had switched to sustainable commuting. Unexpectedly, message content did not predict behavioural change, but mere receipt of a message, versus the control condition, did predict change. The results suggest that sustainable transport campaigns should highlight others‟ cooperation, regardless of their rate of cooperation, and target commuting behavior. Also, participants expected decreases to individually relevant QoL items and improvements to collectively relevant QoL items under a hypothetical reduction in private vehicle use. The findings may be employed by policy-makers to increase acceptance of transportation policies.