Дисертації з теми "Atherton Tablelands"

The Atherton Tablelands basalt aquifer is a major source of groundwater supply for irrigation and other agricultural use. The Tertiary to Quaternary age basaltic aquifer can be regarded as a generally unconfined, layered system, comprising numerous basalt flows separated by palaeo-weathering surfaces and minor alluvial gravels of palaeo-drainage channels. Layers of massive basalt and clay-rich weathered zones act as local aquitards, with some local perched aquifers also present. The aquifer is regarded as a system in which several factors interact to produce the overall characteristics of the hydrogeochemistry of the groundwaters. They include the mineralogical composition of both the basalt aquifer and the thick overlying weathered zone, the porosity and permeability of the basalt aquifer, its thickness, bedrock composition, and climate and topography. The hydrogeochemical processes operating in this aquifer system have been investigated though the analysis of 90 groundwater samples collected from October 1998 to October 1999, groundwater chemistry data provided by the Queensland Department of Natural Resources & Mines for more than 800 groundwater samples, rain water samples collected during 1999 by CSIRO, stream chemistry data provided by CSIRO and James Cook University, and mineralogical and whole rock geochemistry data of drill chip samples. The methods used in this research study include the assessment of groundwater major ion chemistry data and field physico-chemical parameters using hydrochemical facies and statistical approaches, investigation of the mineralogical composition of the aquifer, assessment of concentrations and activities of the ions in solution, the degree of saturation with respect to both primary and secondary minerals, and hydrogeochemical modelling to determine the likely controls on the chemical evolution of these groundwaters. The basaltic groundwaters are mostly Mg-Ca-Na, HCO3 type waters, with electrical conductivities generally less than 250 μS/cm and pH values from 6.5 to 8.5. Dissolved silica (H4SiO4) comprises a large proportion of the total dissolved load, with average concentrations of around 140 mg/L. Concentrations of potassium, chloride and sulphate are low, that is, generally less than 3 mg/L, 15 mg/L and 10 mg/L, respectively. Despite the very low salinity of the Atherton Tablelands basalt groundwaters, the relative concentrations of the major ions are comparable to groundwaters from other basaltic regions, and are consistent with expected waterrock interactions. A variety of multivariate statistical techniques may be used to aid in the analysis of hydrochemical data, including for example, principal component analysis, factor analysis and cluster analysis. Principal component factor analyses undertaken using the hydrochemical data for the Atherton groundwaters has enabled the differentiation of groundwaters from various lithological formations, the underlying geochemical processes controlling groundwater composition in the basalt aquifer to be inferred, relative groundwater residence and flow directions to be inferred and mapping of the estimated thickness of the basalt aquifer. The limitations of multivariate statistical methods have been examined, with emphasis on the issues pertinent to hydrochemical data, that is, data that are compositional and typically, non-normally distributed. The need to validate, normalize and standardize hydrochemical data prior to the application of multivariate statistical methods is demonstrated. Assessment of the saturation states of the Atherton basalt groundwaters with respect to some of the primary minerals present indicate that the groundwaters are mostly at equilibrium or saturated with respect to K-feldspar, and approach equilibrium with respect to the plagioclase feldspars (albite and anorthite) with increasing pH. These groundwaters are at equilibrium or saturated with respect to the major secondary minerals, kaolinite, smectite (Ca-montmorillonite) and gibbsite. They also tend to be saturated with respect to the oxidation products, goethite and hematite, common accessory minerals in the Atherton Tablelands basalt sequence. Silicate mineral weathering processes are the predominant influence on the composition of these basalt groundwaters. These weathering processes include the weathering of pyroxenes, feldspars and other primary minerals to clays, aluminium and iron oxides, amorphous or crystalline silica, carbonates and zeolites, releasing ions to solution. The contribution of substantial organic carbon dioxide to the groundwater is an important factor in the extent to which silicate mineral weathering occurs in this aquifer system. Evaporative enrichment of recharging waters, oxidation and ion-exchange reactions and the uptake of ions from, and decomposition of, organic matter, are processes that have a minor influence on the composition of the basalt groundwaters. The relationships observed between mineralogical compositions, basalt character and groundwater occurrence in the Atherton Tablelands region improved the understanding how groundwater is stored and transmitted in this basalt aquifer system. Groundwater is mostly stored in vesicular basalt that may be fresh to highly weathered, and movement of this water is facilitated by pathways through both vesicular and fractured basalt. Related work undertaken as part of this research project showed that the groundwater flow patterns defined by the hydrogeochemical interpretations correspond well with the spatial trends in water level fluctuations, and response to recharge events in particular. Groundwater baseflow to streams and discharge to topographic lows in the Atherton Tablelands region is indicated by the relationships between the major cations and anions in the stream waters. Fracture zones are likely to be preferred pathways of groundwater movement. Recharge estimates, based on a chloride mass balance, range from 310 mm/yr in the north-western part of the study area (north of Atherton) to 600 mm/yr in the wetter southern and eastern parts of the study area. These recharge estimates should be treated with caution however, due to the low groundwater chloride concentrations and the high variability in rainfall chloride concentrations. The findings of this research project have improved the understanding of the hydrogeochemical processes controlling the composition of the low salinity basalt groundwaters in the Atherton Tablelands region, and are applicable to other basalt groundwater systems, particularly those in high rainfall environments.

The Atherton Tablelands basalt aquifer is a major source of groundwater supply for irrigation and other agricultural use. The Tertiary to Quaternary age basaltic aquifer can be regarded as a generally unconfined, layered system, comprising numerous basalt flows separated by palaeo-weathering surfaces and minor alluvial gravels of palaeo-drainage channels. Layers of massive basalt and clay-rich weathered zones act as local aquitards, with some local perched aquifers also present. The aquifer is regarded as a system in which several factors interact to produce the overall characteristics of the hydrogeochemistry of the groundwaters. They include the mineralogical composition of both the basalt aquifer and the thick overlying weathered zone, the porosity and permeability of the basalt aquifer, its thickness, bedrock composition, and climate and topography. The hydrogeochemical processes operating in this aquifer system have been investigated though the analysis of 90 groundwater samples collected from October 1998 to October 1999, groundwater chemistry data provided by the Queensland Department of Natural Resources & Mines for more than 800 groundwater samples, rain water samples collected during 1999 by CSIRO, stream chemistry data provided by CSIRO and James Cook University, and mineralogical and whole rock geochemistry data of drill chip samples. The methods used in this research study include the assessment of groundwater major ion chemistry data and field physico-chemical parameters using hydrochemical facies and statistical approaches, investigation of the mineralogical composition of the aquifer, assessment of concentrations and activities of the ions in solution, the degree of saturation with respect to both primary and secondary minerals, and hydrogeochemical modelling to determine the likely controls on the chemical evolution of these groundwaters. The basaltic groundwaters are mostly Mg-Ca-Na, HCO3 type waters, with electrical conductivities generally less than 250 μS/cm and pH values from 6.5 to 8.5. Dissolved silica (H4SiO4) comprises a large proportion of the total dissolved load, with average concentrations of around 140 mg/L. Concentrations of potassium, chloride and sulphate are low, that is, generally less than 3 mg/L, 15 mg/L and 10 mg/L, respectively. Despite the very low salinity of the Atherton Tablelands basalt groundwaters, the relative concentrations of the major ions are comparable to groundwaters from other basaltic regions, and are consistent with expected waterrock interactions. A variety of multivariate statistical techniques may be used to aid in the analysis of hydrochemical data, including for example, principal component analysis, factor analysis and cluster analysis. Principal component factor analyses undertaken using the hydrochemical data for the Atherton groundwaters has enabled the differentiation of groundwaters from various lithological formations, the underlying geochemical processes controlling groundwater composition in the basalt aquifer to be inferred, relative groundwater residence and flow directions to be inferred and mapping of the estimated thickness of the basalt aquifer. The limitations of multivariate statistical methods have been examined, with emphasis on the issues pertinent to hydrochemical data, that is, data that are compositional and typically, non-normally distributed. The need to validate, normalize and standardize hydrochemical data prior to the application of multivariate statistical methods is demonstrated. Assessment of the saturation states of the Atherton basalt groundwaters with respect to some of the primary minerals present indicate that the groundwaters are mostly at equilibrium or saturated with respect to K-feldspar, and approach equilibrium with respect to the plagioclase feldspars (albite and anorthite) with increasing pH. These groundwaters are at equilibrium or saturated with respect to the major secondary minerals, kaolinite, smectite (Ca-montmorillonite) and gibbsite. They also tend to be saturated with respect to the oxidation products, goethite and hematite, common accessory minerals in the Atherton Tablelands basalt sequence. Silicate mineral weathering processes are the predominant influence on the composition of these basalt groundwaters. These weathering processes include the weathering of pyroxenes, feldspars and other primary minerals to clays, aluminium and iron oxides, amorphous or crystalline silica, carbonates and zeolites, releasing ions to solution. The contribution of substantial organic carbon dioxide to the groundwater is an important factor in the extent to which silicate mineral weathering occurs in this aquifer system. Evaporative enrichment of recharging waters, oxidation and ion-exchange reactions and the uptake of ions from, and decomposition of, organic matter, are processes that have a minor influence on the composition of the basalt groundwaters. The relationships observed between mineralogical compositions, basalt character and groundwater occurrence in the Atherton Tablelands region improved the understanding how groundwater is stored and transmitted in this basalt aquifer system. Groundwater is mostly stored in vesicular basalt that may be fresh to highly weathered, and movement of this water is facilitated by pathways through both vesicular and fractured basalt. Related work undertaken as part of this research project showed that the groundwater flow patterns defined by the hydrogeochemical interpretations correspond well with the spatial trends in water level fluctuations, and response to recharge events in particular. Groundwater baseflow to streams and discharge to topographic lows in the Atherton Tablelands region is indicated by the relationships between the major cations and anions in the stream waters. Fracture zones are likely to be preferred pathways of groundwater movement. Recharge estimates, based on a chloride mass balance, range from 310 mm/yr in the north-western part of the study area (north of Atherton) to 600 mm/yr in the wetter southern and eastern parts of the study area. These recharge estimates should be treated with caution however, due to the low groundwater chloride concentrations and the high variability in rainfall chloride concentrations. The findings of this research project have improved the understanding of the hydrogeochemical processes controlling the composition of the low salinity basalt groundwaters in the Atherton Tablelands region, and are applicable to other basalt groundwater systems, particularly those in high rainfall environments.

This study investigated the utility to vertebrates of upland linear riparian rainforest fragments on the Atherton and Evelyn Tablelands in the Australian Wet Tropics region, north Queensland. Similar linear fragments were selected, that varied in forest age and their connectivity to large areas of continuous forest:- (connected primary (N=6), isolated primary (N=5), connected secondary (N=6) and isolated secondary (N=7)). Primary sites had either never been cleared or only subject to selective logging, while secondary forest had been completely cleared and allowed to regenerate for at least 30 years. These linear fragments were contrasted with riparian sites within continuous forest sites (N=6 to 7), which were situated in State Forest or National Parks, and sites within the cleared matrix (pasture, N=6). Vertebrates surveyed were birds, ground-dwelling mammals and reptiles, particularly leaf-litter skinks. All surveys were conducted between September and December in 2001 and/or 2000. Chapter 2 investigates the effects of forest age, isolation and structural vegetation features on bird assemblages within linear riparian fragments of rainforest. Bird surveys and structural vegetation assessments were conducted within connected and isolated primary and secondary linear fragments, and compared with those of continuous forest habitat (N=6) and pasture. There were strong effects of forest age; all three types of primary rainforest had higher values than secondary rainforest for most measured attributes of vegetation structure (including canopy height and cover; and frequency of large-diameter trees, lianes, epiphytes, strangler figs; and woody debris), but lower frequencies of tree ferns and thorny scramblers. Sites within primary rainforest also had a greater frequency of many bird species across different guilds of habitat, feeding and movement. Assemblages of rainforest-dependent birds showed an effect of isolation, although its strength was less than that of forest age. Isolated fragments of primary rainforest differed significantly from continuous primary rainforest in their rainforest-dependent bird species assemblages (and had lower species richness), and isolated fragments of secondary rainforest differed from those that were connected. There was a significant association between the species composition of rainforest birds and some measured vegetation parameters across all sites, but not within primary or secondary sites. Vegetation differences did not explain the lowered frequency of several species in isolated fragments. Limited dispersal seems unlikely to be a main cause, and causal processes probably vary among species. Specialist rainforest species endemic to the Wet Tropics region showed stronger responses to present-day rainforest age and fragmentation than those not endemic. Variation in nest depredation levels associated with rainforest fragmentation (edge effects) is examined in Chapter 3. Artificial nests were placed in the forest understorey at seven edge sites where continuous forest adjoined pasture, seven interiors (about one kilometre from the edge), and six primary linear riparian forest remnants (50-100 m wide) that were connected to continuous forest. Four nest types were compared, representing different combinations of two factors; height (ground, shrub) and shape (open, domed). At each site, four nests of each type, containing one quail egg and two model plasticine eggs, were interspersed about 15 m apart within a 160 m transect. Predators were identified from marks on the plasticine eggs. The overall depredation rate was 66.5% of 320 nests' contents damaged over a three-day period. Large rodents, especially the rat Uromys caudimaculatus, and birds, especially the spotted catbird Ailuroedus melanotis, were the main predators. Mammals comprised 56.5% and birds 31.0% of identified predators, with 12.5% of unknown identity. The depredation rate did not vary among site-types, or between open and domed nests, and there were no statistically significant interactions. Nest height strongly affected depredation rates by particular types of predator; depredation rates by mammals were highest at ground nests, whereas attacks by birds were most frequent at shrub nests. These effects counterbalanced so that overall there was little net effect of nest height. Mammals accounted for 78.4% of depredated ground nests and birds for at least 47.4% of shrub nests (and possibly up to 70.1%). The main predators were species characteristic of rainforest, rather than habitat generalists, open-country or edge specialists. For birds that nest in the tropical rainforest understorey of the study region, it is unlikely that edges and linear remnants presently function as ecological population sinks due to mortality associated with increased nest depredation. The use of linear riparian remnants by small ground-dwelling mammals and reptiles (mainly leaf litter skinks), is reported in Chapter 4. Site types were continuous rainforest, connected and isolated linear fragments of both uncleared primary rainforest and secondary regrowth rainforest. Mammals were also surveyed in pasture sites. Neither reptile species richness nor abundance varied significantly among site types. Although mammal species richness varied significantly between site types, with isolated primary sites containing highest species richness, overall mammal abundance did not differ significantly among site types. Pasture sites differed significantly from all rainforest sites in their mammal species composition, and were dominated by the introduced house mouse (Mus musculus). This species was absent from all rainforest sites, which were characterised by moderate abundances of bush rat/Cape York rat Rattus fuscipes/leucopus, fawn-footed melomys Melomys cervinipes and giant white-tailed rat Uromys caudimaculatus. None of these species varied significantly in abundance among site types, although the giant white-tailed rat showed a trend (P=0.09) for reduced abundance in isolated secondary sites. A single reptile species, the prickly forest skink Gnypetoscincus queenslandiae, occurred in sufficient numbers for individual analysis, and its abundance varied significantly among the forested site types, being less abundant in all linear fragments than in continuous forest sites. The utility of linear riparian rainforest for vertebrates appears to be species-specific and involves many factors. However, overall, species endemic to the Wet Tropics (which are hence of the highest conservation significance) appear to be the most sensitive to fragmentation. These species were most likely to show altered abundances or frequencies of occurrence due to isolation, forest age, and habitat linearity. The ecology of species within this group warrants further investigation within fragmented and non-fragmented regions of the Tablelands. For many other vertebrates examined in this study, there appears to be sufficient functional connectedness between remnants on the Tablelands to minimise the effects of fragmentation. Nevertheless, the lower density of many of these species in pasture may indicate that their long-term persistence within the fragmented rainforest areas could benefit from the maintenance or establishment of habitat linkages. Certainly, if the current rainforest vegetation cover were further reduced, or if the land use in the matrix became more intensive, the establishment of specific habitat linkages could become more important as existing dispersal routes could be lost. It also appears that nest depredation levels are unlikely to limit the value of linear rainforest remnants and other small rainforest remnants as breeding habitat for birds (at least for understorey-nesting species), relative to more intact rainforest, in the study region.

This study investigated the utility to vertebrates of upland linear riparian rainforest fragments on the Atherton and Evelyn Tablelands in the Australian Wet Tropics region, north Queensland. Similar linear fragments were selected, that varied in forest age and their connectivity to large areas of continuous forest:- (connected primary (N=6), isolated primary (N=5), connected secondary (N=6) and isolated secondary (N=7)). Primary sites had either never been cleared or only subject to selective logging, while secondary forest had been completely cleared and allowed to regenerate for at least 30 years. These linear fragments were contrasted with riparian sites within continuous forest sites (N=6 to 7), which were situated in State Forest or National Parks, and sites within the cleared matrix (pasture, N=6). Vertebrates surveyed were birds, ground-dwelling mammals and reptiles, particularly leaf-litter skinks. All surveys were conducted between September and December in 2001 and/or 2000. Chapter 2 investigates the effects of forest age, isolation and structural vegetation features on bird assemblages within linear riparian fragments of rainforest. Bird surveys and structural vegetation assessments were conducted within connected and isolated primary and secondary linear fragments, and compared with those of continuous forest habitat (N=6) and pasture. There were strong effects of forest age; all three types of primary rainforest had higher values than secondary rainforest for most measured attributes of vegetation structure (including canopy height and cover; and frequency of large-diameter trees, lianes, epiphytes, strangler figs; and woody debris), but lower frequencies of tree ferns and thorny scramblers. Sites within primary rainforest also had a greater frequency of many bird species across different guilds of habitat, feeding and movement. Assemblages of rainforest-dependent birds showed an effect of isolation, although its strength was less than that of forest age. Isolated fragments of primary rainforest differed significantly from continuous primary rainforest in their rainforest-dependent bird species assemblages (and had lower species richness), and isolated fragments of secondary rainforest differed from those that were connected. There was a significant association between the species composition of rainforest birds and some measured vegetation parameters across all sites, but not within primary or secondary sites. Vegetation differences did not explain the lowered frequency of several species in isolated fragments. Limited dispersal seems unlikely to be a main cause, and causal processes probably vary among species. Specialist rainforest species endemic to the Wet Tropics region showed stronger responses to present-day rainforest age and fragmentation than those not endemic. Variation in nest depredation levels associated with rainforest fragmentation (edge effects) is examined in Chapter 3. Artificial nests were placed in the forest understorey at seven edge sites where continuous forest adjoined pasture, seven interiors (about one kilometre from the edge), and six primary linear riparian forest remnants (50-100 m wide) that were connected to continuous forest. Four nest types were compared, representing different combinations of two factors; height (ground, shrub) and shape (open, domed). At each site, four nests of each type, containing one quail egg and two model plasticine eggs, were interspersed about 15 m apart within a 160 m transect. Predators were identified from marks on the plasticine eggs. The overall depredation rate was 66.5% of 320 nests' contents damaged over a three-day period. Large rodents, especially the rat Uromys caudimaculatus, and birds, especially the spotted catbird Ailuroedus melanotis, were the main predators. Mammals comprised 56.5% and birds 31.0% of identified predators, with 12.5% of unknown identity. The depredation rate did not vary among site-types, or between open and domed nests, and there were no statistically significant interactions. Nest height strongly affected depredation rates by particular types of predator; depredation rates by mammals were highest at ground nests, whereas attacks by birds were most frequent at shrub nests. These effects counterbalanced so that overall there was little net effect of nest height. Mammals accounted for 78.4% of depredated ground nests and birds for at least 47.4% of shrub nests (and possibly up to 70.1%). The main predators were species characteristic of rainforest, rather than habitat generalists, open-country or edge specialists. For birds that nest in the tropical rainforest understorey of the study region, it is unlikely that edges and linear remnants presently function as ecological population sinks due to mortality associated with increased nest depredation. The use of linear riparian remnants by small ground-dwelling mammals and reptiles (mainly leaf litter skinks), is reported in Chapter 4. Site types were continuous rainforest, connected and isolated linear fragments of both uncleared primary rainforest and secondary regrowth rainforest. Mammals were also surveyed in pasture sites. Neither reptile species richness nor abundance varied significantly among site types. Although mammal species richness varied significantly between site types, with isolated primary sites containing highest species richness, overall mammal abundance did not differ significantly among site types. Pasture sites differed significantly from all rainforest sites in their mammal species composition, and were dominated by the introduced house mouse (Mus musculus). This species was absent from all rainforest sites, which were characterised by moderate abundances of bush rat/Cape York rat Rattus fuscipes/leucopus, fawn-footed melomys Melomys cervinipes and giant white-tailed rat Uromys caudimaculatus. None of these species varied significantly in abundance among site types, although the giant white-tailed rat showed a trend (P=0.09) for reduced abundance in isolated secondary sites. A single reptile species, the prickly forest skink Gnypetoscincus queenslandiae, occurred in sufficient numbers for individual analysis, and its abundance varied significantly among the forested site types, being less abundant in all linear fragments than in continuous forest sites. The utility of linear riparian rainforest for vertebrates appears to be species-specific and involves many factors. However, overall, species endemic to the Wet Tropics (which are hence of the highest conservation significance) appear to be the most sensitive to fragmentation. These species were most likely to show altered abundances or frequencies of occurrence due to isolation, forest age, and habitat linearity. The ecology of species within this group warrants further investigation within fragmented and non-fragmented regions of the Tablelands. For many other vertebrates examined in this study, there appears to be sufficient functional connectedness between remnants on the Tablelands to minimise the effects of fragmentation. Nevertheless, the lower density of many of these species in pasture may indicate that their long-term persistence within the fragmented rainforest areas could benefit from the maintenance or establishment of habitat linkages. Certainly, if the current rainforest vegetation cover were further reduced, or if the land use in the matrix became more intensive, the establishment of specific habitat linkages could become more important as existing dispersal routes could be lost. It also appears that nest depredation levels are unlikely to limit the value of linear rainforest remnants and other small rainforest remnants as breeding habitat for birds (at least for understorey-nesting species), relative to more intact rainforest, in the study region
Thesis (Masters)
Master of Philosophy (MPhil)
Australian School of Environmental Studies
Full Text

Thesis (M.Phil.) -- Griffith University, 2004.
Facsimile of the author's original dissertation. Pagination of document: x, 121 leaves. Includes bibliographical references. Also available online via the World Wide Web.

Lumholtz’s tree-kangaroo (Dendrolagus Iumholtzi), one of Australia’s largest folivores and one of only two tree-kangaroo species endemic to Australia and far north Queensland’s Wet Tropics. D. Iumholtzi are most commonly found in the fragmented rainforests that remain within an agricultural matrix in a relatively small area on the Atherton Tablelands. Unfortunately the majority of these fragments are on privately owned land and are not totally protected from clearing, therefore their long-term persistence is threatened by land clearing, further habitat fragmentation and mortality from dogs and cars. Although there have been a few studies on the ecology and habitat use of D. Iumholtzi, our current knowledge is limited. A more comprehensive understanding of spatial and floristic habitat use is essential for the conservation and management of D. Iumholtzi. This study examined the spatial organisation and habitat utilisation of Lumholtz’s tree-kangaroos in a Type lb rainforest fragment on the Atherton Tablelands and compared this to earlier studies (Procter-Gray 1985, Newell 1999). The two previous studies were both undertaken on the same spatially restricted rainforest type (Type Sb) only a couple of hundred metres apart, so this study has provided an important expansion of our understanding of D. Iumholtzi ecology across space and rainforest types. There were no significant effects of rainforest type on the home range sizes of D. Iumholtzi (Procter-Gray 1985, Newell 1999, This study). Male D. Iumholtziin this study held home ranges of 2.1 ± 0.7 ha (90% HM) overlapping that of several females but not other males, and females had exclusive home ranges of 2.1 ± 0.8 ha (90% HM) of a similar size to males. However, there was a large amount of variation in female home range sizes (0.1 —4.9 ha). Body weight did not explain this variation in home range sizes. This study also examined structural and floristic characteristics of the habitat and investigated if these could be used to model D. Iumholtzi habitat usage. The structural and floristic characters measured in this study could not be used to determine the focus of habitat usage. This study has shown that there is a more complex association between D. Iumholtzi and its use of habitat other than the structural characters of the habitat. D. Iumholtzi do select specific tree species, but there are strongly expressed individual preferences, similar to other arboreal folivores. The reasons for these specific choices are currently unclear but D. Iumholtzi are likely to choose trees for foliage characters, such as the levels of nutrients or plant defences, rather than for the species at a taxonomic level. This is also consistent with other arboreal folivores such as koalas and leaf-eating monkeys. The determination of which foliar characters are driving tree species or individual tree choice will require further research. This study tested and rejected a number of previous hypotheses regarding the characteristics determining D. Iumholtzi habitat use. They are not edge specialists, do not prefer regrowth or areas with a large variation in canopy height, or areas with high species diversity or density. The gastrointestinal morphology of D. Iumholtzi shares a number of features with other foregut fermenting folivores. Compared to other macropodids, D. Iumholtzi has a large sacciform forestomach and a large overall stomach capacity, and more similar in size and morphology to that of other arboreal foregut fermenting folivores, such as colobine monkeys. It is likely that these characteristics are adaptive for its diet of rainforest leaves. Lumholtz’s tree-kangaroos can be simply aged using a tooth wear index developed during this study. Aging is essential for establishing demographics, such as age specific mortality and fecundity of populations, currently unknown in D. Iumholtzi. Without the ability to age populations we cannot reliably undertake valuable estimations such as population viability analysis, which require these parameters. Additionally, this study has highlighted that not only one rainforest type is important to D. Iumholtzi and that more emphasis should be made on the preservation and restoration of all rainforest types. Furthermore, it is vital that all rainforest fragments including riparian zones, regrowth and corridors and stepping stones, should be conserved, rehabilitated and areas replanted as D. Iumholtzi habitat, as they are crucial to the species long term survival.

Lumholtz’s tree-kangaroo (Dendrolagus Iumholtzi), one of Australia’s largest folivores and one of only two tree-kangaroo species endemic to Australia and far north Queensland’s Wet Tropics. D. Iumholtzi are most commonly found in the fragmented rainforests that remain within an agricultural matrix in a relatively small area on the Atherton Tablelands. Unfortunately the majority of these fragments are on privately owned land and are not totally protected from clearing, therefore their long-term persistence is threatened by land clearing, further habitat fragmentation and mortality from dogs and cars. Although there have been a few studies on the ecology and habitat use of D. Iumholtzi, our current knowledge is limited. A more comprehensive understanding of spatial and floristic habitat use is essential for the conservation and management of D. Iumholtzi. This study examined the spatial organisation and habitat utilisation of Lumholtz’s tree-kangaroos in a Type lb rainforest fragment on the Atherton Tablelands and compared this to earlier studies (Procter-Gray 1985, Newell 1999). The two previous studies were both undertaken on the same spatially restricted rainforest type (Type Sb) only a couple of hundred metres apart, so this study has provided an important expansion of our understanding of D. Iumholtzi ecology across space and rainforest types. There were no significant effects of rainforest type on the home range sizes of D. Iumholtzi (Procter-Gray 1985, Newell 1999, This study). Male D. Iumholtziin this study held home ranges of 2.1 ± 0.7 ha (90% HM) overlapping that of several females but not other males, and females had exclusive home ranges of 2.1 ± 0.8 ha (90% HM) of a similar size to males. However, there was a large amount of variation in female home range sizes (0.1 —4.9 ha). Body weight did not explain this variation in home range sizes. This study also examined structural and floristic characteristics of the habitat and investigated if these could be used to model D. Iumholtzi habitat usage. The structural and floristic characters measured in this study could not be used to determine the focus of habitat usage. This study has shown that there is a more complex association between D. Iumholtzi and its use of habitat other than the structural characters of the habitat. D. Iumholtzi do select specific tree species, but there are strongly expressed individual preferences, similar to other arboreal folivores. The reasons for these specific choices are currently unclear but D. Iumholtzi are likely to choose trees for foliage characters, such as the levels of nutrients or plant defences, rather than for the species at a taxonomic level. This is also consistent with other arboreal folivores such as koalas and leaf-eating monkeys. The determination of which foliar characters are driving tree species or individual tree choice will require further research. This study tested and rejected a number of previous hypotheses regarding the characteristics determining D. Iumholtzi habitat use. They are not edge specialists, do not prefer regrowth or areas with a large variation in canopy height, or areas with high species diversity or density. The gastrointestinal morphology of D. Iumholtzi shares a number of features with other foregut fermenting folivores. Compared to other macropodids, D. Iumholtzi has a large sacciform forestomach and a large overall stomach capacity, and more similar in size and morphology to that of other arboreal foregut fermenting folivores, such as colobine monkeys. It is likely that these characteristics are adaptive for its diet of rainforest leaves. Lumholtz’s tree-kangaroos can be simply aged using a tooth wear index developed during this study. Aging is essential for establishing demographics, such as age specific mortality and fecundity of populations, currently unknown in D. Iumholtzi. Without the ability to age populations we cannot reliably undertake valuable estimations such as population viability analysis, which require these parameters. Additionally, this study has highlighted that not only one rainforest type is important to D. Iumholtzi and that more emphasis should be made on the preservation and restoration of all rainforest types. Furthermore, it is vital that all rainforest fragments including riparian zones, regrowth and corridors and stepping stones, should be conserved, rehabilitated and areas replanted as D. Iumholtzi habitat, as they are crucial to the species long term survival.

Insects are well recognised as being the major contributor to global biodiversity, and for their critical involvement in many biotic interactions. Most of the insect diversity is found in tropical rainforests. However, these forests are threatened by high rates of clearing and the subsequent fragmentation of remaining habitat. The effects on biota, particularly insects, are poorly understood as are the mechanisms mediating faunal changes. Reforestation could potentially alleviate some of the deleterious effects of forest loss and fragmentation. However, because reforestation is a relatively new endeavour, it is little known just how much insect biodiversity can be supported by reforestation and what factors influence insect colonisation. These issues were investigated in the Atherton Tablelands of north-eastern Australia, a landscape whose rainforest has been heavily cleared and fragmented over the last 80 years, but is also the focus of reforestation efforts. To quantify the effects of rainforest loss and fragmentation, pasture sites were compared with small rainforest fragments, and with the edges and interiors of large rainforest fragments (24 sites in total). Sites with replanted rainforest (planted with a high diversity of plants) were also included. These varied in their age (2-17 yrs) and their distance (0-4.5 km) from existing rainforest (24 sites in total). Another set of reforested sites was also studied but these differed in their planting style (number of plant species, spacing etc). This second set of sites was located in two regions: the Atherton Tablelands (50 sites), and in the subtropics of eastern Australia (54 sites). At each site, beetle assemblages were surveyed using methods that sample beetles near the ground (four ground-based flight interception traps in the first set of sites and ten pitfall traps in the second set of sites), and then the assemblages among site-types were compared. Over 32,000 beetles were caught and identified to the level of family, and of these, 15,206 were identified further to the level of species. Very few beetle species were present in pasture, suggesting that converting rainforest into pasture has a very strong negative effect on beetle diversity and species composition. Irrespective of rainforest fragment size, beetle species composition in drier rainforest habitats was different from that of moister rainforest. Beetle species composition also differed between small remnants and interior rainforest: drier-associated species were more abundant in small remnants, whereas wetter-associated species were more abundant in interiors. This pattern can be best attributed to a fragmentation effect mediated by differences in microclimate. With the exception of differences between rainforest and pasture, these results were generally not observed among beetle assemblages identified to coarser taxonomic groups (family, feeding guild, and body size). Among replanted rainforest, older sites and those adjacent to rainforest had a more rainforest-like beetle species composition. However, even the closer and older sites had a substantially lower abundance and richness of rainforest-associated beetles than did rainforest. Age effects were generally stronger than distance effects. Beetle assemblage similarity to rainforest was more strongly correlated with structural similarity to rainforest than with site age or distance from rainforest. Thus the use of revegetation techniques which lead to more rainforest-like structural conditions appears to be of over-riding importance in catalysing the rapid acquisition of rainforest beetle assemblages in the initial stages of restoration. Nevertheless, not all beetle species were equally affected by the factors tested. Large-bodied beetle species (>5 mm) were more strongly influenced by distance than small-bodied species (<5 mm), suggesting that small-bodied species are better dispersers, and thus are amongst the first to colonise new habitats. Spatial ubiquity in rainforest was not a good predictor of a species' dispersal ability. Interestingly, fewer of the broader groups (family, feeding guild, and body size) showed the response to distance evident at the species level although they showed differences between reforested sites differing in age, and between reforested and reference site-types. Therefore, these results and those from the fragmentation study suggest that information at the species level is more sensitive to environmental change than data identified to a coarser level of taxonomy or grouped according to feeding ecology or body size. For the pitfall-trapped beetles in the second reforested site network, beetle assemblages in all styles of reforestation were intermediate in species composition between pasture and rainforest. The similarity of beetle assemblages to intact rainforest increased with the age and structural complexity of reforested sites, although again structural complexity appeared to be of overriding importance. This study has shown that even small patches of rainforest and reforested areas can support diverse rainforest-dependent beetle assemblages. A range of factors influence the development of beetle assemblages in reforested sites although not all species are equally affected. However, even structurally complex reforested sites cannot provide a short- or medium-term substitute for the retention of intact rainforest.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Faculty of Environmental Studies
Full Text

The Atherton Tablelands, west of Cairns in Far North Queensland, comprise some of the richest agricultural lands in Australia. The area was settled from the 1880s, following the discovery of gold and other minerals on the Palmer River, the Hodgkinson and the Herberton fields. Situated as it is on the economic and geographic periphery of Australia, government sponsored agriculture on the Tablelands was seen not so much as a food producing venture, as a means of closer settlement and strategic defence in accord with the White Australia Policy. Maize, dairy, and tobacco industries were set up by opening Crown Land for selection under conditions which inevitably caused destruction of thousands of acres of valuable rainforest, with consequent land degradation, erosion, and invasions of weeds. Subsequently, production became less than optimal, and without assured markets, transport systems and access to communications, the farmers struggled with subsistence conditions. In order to keep unviable industries alive, successive Queensland and Commonwealth governments intervened with a plethora of schemes which had the effect of subjecting farm families to years of poverty and despair. In the process, the industries became subject to ever-increasing regulation which stifled enterprise, and led to over-production of commodities for the available market. All of the industries were supported to some degree by mechanisms ranging from statutory marketing to subsidies, bounties, direct grants and tariff protection. When Australian governments moved to realign the economy of the nation according to neo-liberal principles, all of the support mechanisms which had allowed the industries to stay alive were withdrawn over a period of thirty years. The result has been predictable. Tobacco growing in the area has ceased, the dairy industry has declined to the point where it is unlikely to exist for much beyond 2010, and the maize industry is surviving as a provider of stock feed to the local market. This study traces the establishment, development, and rationalization of each industry, and records the effects of these processes on the people, the environment, the wider community, and the politics of the area. In terms of regional decline, it is a microcosm case study of the effects of government intervention, both in the process of regulation and deregulation. The lessons to be drawn from the study point to profound implications for the production of food within a sustainable environment in Australia.

The Atherton Tablelands, west of Cairns in Far North Queensland, comprise some of the richest agricultural lands in Australia. The area was settled from the 1880s, following the discovery of gold and other minerals on the Palmer River, the Hodgkinson and the Herberton fields. Situated as it is on the economic and geographic periphery of Australia, government sponsored agriculture on the Tablelands was seen not so much as a food producing venture, as a means of closer settlement and strategic defence in accord with the White Australia Policy. Maize, dairy, and tobacco industries were set up by opening Crown Land for selection under conditions which inevitably caused destruction of thousands of acres of valuable rainforest, with consequent land degradation, erosion, and invasions of weeds. Subsequently, production became less than optimal, and without assured markets, transport systems and access to communications, the farmers struggled with subsistence conditions. In order to keep unviable industries alive, successive Queensland and Commonwealth governments intervened with a plethora of schemes which had the effect of subjecting farm families to years of poverty and despair. In the process, the industries became subject to ever-increasing regulation which stifled enterprise, and led to over-production of commodities for the available market. All of the industries were supported to some degree by mechanisms ranging from statutory marketing to subsidies, bounties, direct grants and tariff protection. When Australian governments moved to realign the economy of the nation according to neo-liberal principles, all of the support mechanisms which had allowed the industries to stay alive were withdrawn over a period of thirty years. The result has been predictable. Tobacco growing in the area has ceased, the dairy industry has declined to the point where it is unlikely to exist for much beyond 2010, and the maize industry is surviving as a provider of stock feed to the local market. This study traces the establishment, development, and rationalization of each industry, and records the effects of these processes on the people, the environment, the wider community, and the politics of the area. In terms of regional decline, it is a microcosm case study of the effects of government intervention, both in the process of regulation and deregulation. The lessons to be drawn from the study point to profound implications for the production of food within a sustainable environment in Australia.

This thesis is about how people develop attachments to places, and what this means for natural resource management. The concept of ‘sense of place’ is generating strong interest in the domain of natural resource management. In particular, the concept offers considerable potential as a way of integrating social, ecological and economic dimensions of environment. This makes the concept highly relevant to an emerging agenda from a range of disciplines and management approaches concerned with the links between social systems and natural systems at local and regional scales (Berkes and Folke 1998; Cheng Kruger and Daniels 2003; Plumwood 2002).¶ Recent interest in place has led to a research agenda for exploring how this concept can play a greater role in resource management (Cantrill and Senecah 2001). Central to this research agenda are questions of how attachments to places are influenced and how sense of place changes over time. In response to the emerging role of sense of place in natural resource management and the research agenda for exploring this concept, this thesis is concerned with three questions: what are the key influences on sense of place?; what is the relationship between sense of place and activities in practice?; and how do people learn about places and respond to change? To explore these questions, the thesis presents findings from interviews with 40 participants in case studies of the Atherton Tablelands and Woodstock, north Queensland. The research employed a purposeful sampling design with the aim of capturing as many different senses of place as possible within the limits of this study. Participants represented a broad range of land uses, ethnic backgrounds, ages and durations of time in the place of the interview. The data from these interviews were analysed using qualitative methods drawing on grounded theory (Charmanz 2000) and influenced by adaptive theory (Layder 1998). The research included a focus on honouring human experience (Braud and Anderson 1998), and also recognising the importance of prior research on how people develop a sense of place (Piaget 1971; Relph 1976).¶ ...

This study focuses on the application of humification to organic rich deposits as a measure of palaeohydrological change over the last 37 ka on the Atherton Tableland of northeastern Australia. Studies in southern Australia have illustrated the effectiveness of certain volcanic landscape features (specifically crater basins) to act as rain gauges recording changes in both contemporary and past rainfall. Preliminary field researches on the Atherton Tableland in 2009 identified two volcanic crater basins, Bromfield Swamp and Mount Quincan crater, that retained deep peat and organic-rich sequences in basins that had a large surface area relative to their total catchment area, indicating lake systems little impacted by fluvial processes. Sediment cores were extracted from each basin using a piston corer mounted on a stationary floating platform. In each case the sediment profiles where not homogenous but changed with increasing depth from surface peats to gyttja and laminated organic sediments through to fine-grained inorganic sediments at depth. Palaeohydrological proxy indicators, including humification, pollen analysis, stable isotope analysis (Delta 13C), C/N analysis, charcoal analysis, magnetic susceptibility, grain size and ITRAX scans were applied to the sediments to infer changes in past environments and climate. The application of humification as a proxy for palaeohydrological change in Australian landscapes is poorly understood. The thesis aims to (i) test the validity of peat humification as a reliable proxy indicator of past variability, (ii) apply humification at high resolution to deep peat deposits (Bromfield Swamp and Mount Quincan crater) spanning the last 4000 years and compare these to existing palaeoclimate records, and (iii) produce a near-continuous record of changes in relative precipitation spanning the last 37 ka years using a suite of palaeohydrological proxies applied to organic and inorganic clastic sediments from Bromfield Swamp. The study shows that peat humification analysis can identify wet and dry shifts in a peat sequences from the humid tropics with significant correlation between the humification record and other proxies used in determinations of past climate (pollen, Delta 13C, C/N, macrocharcoal). Seventeen wet and fourteen dry shifts were detected in the last 4000 years from peat humification at Bromfield Swamp and Mount Quincan crater. The long sediment record (ITRAX, magnetic susceptibility, grain size and humification) from Bromfield Swamp shows that prior to 4000 years BP there are a further fifteen significant wet periods that can be identified in the 37 ka sedimentary record for Bromfield Swamp. These date to 36450, 36110, 34720, 29050, 27560, 2678, 26100, 25800, 24660, 24240, 23670, 22530, 13610, 11880, 10020, 8140, 3980 cal. yr BP. The study shows that high resolution ITRAX scanning combined with multi-proxy analysis (humification, pollen, charcoal, grain size and magnetic susceptibility) of organic-rich sediments can produce robust palaeoclimatic data, allowing identification of wet and dry shifts in a complex sedimentary sequence from the late Pleistocene-Late Holocene. The XRF record identifies periods of abrupt climate change which strengthens the capacity to correlate these changes with high-resolution records from terrestrial sites across the Southern Hemisphere and potentially, global events.

This thesis examines the development of Australian Army jungle warfare doctrine and training during the Second World War. The Australian Army transformed itself from a military force ill-prepared for conflict of any type in 1939 into one of the most professional, experienced and highly trained forces in jungle warfare in the world by 1945. The thesis analyses how this transformation occurred and, in doing so, provides a case study in institutional learning. Attempting to discover how an organisation learns is vital: unless these processes of adaptation are identified, it is extremely difficult for an organisation to apply successfully the lessons in the future. For no institution is this more pertinent than for the military. Armed forces unable to adapt to unforeseen challenges were frequently defeated with often profound consequences. The thesis identifies this process of development and adaptation by the Australian Army from 1941 to 1945.

Tropical rainforest rehabilitation is one method to recreate, establish, and accelerate natural successional processes. Tropical rehabilitation has occurred on the Atherton Tableland for 15 years. Currently, rehabilitated sites on the Atherton Tableland are monitored by tree planting agencies for two to three years to reduce exotic species. The 10-12 years following the last monitoring period provides the opportunity to investigate successional processes of these rehabilitated sites. One method to investigate rehabilitation management is through the soil seed bank. The composition and recruitment pattern of seeds in the soil seed bank may offer information on species that have the potential to germinate in rehabilitated sites following a disturbance. This knowledge is useful to predict future successional patterns within rehabilitated sites. This study investigated the soil seed bank composition of rehabilitated sites adjacent to – and isolated from – remnant rainforest. In addition, it was determined whether distance from seed source influenced exotic species composition and native species recruitment that occurred to rehabilitated sites. Seventeen rainforest study sites were chosen for investigation: six remnant rainforest sites, six rehabilitated sites adjacent to remnant rainforest, and five rehabilitated sites isolated from remnant rainforest. Twenty soil samples were collected (60 x 60 x 50 mm deep) for each site, and overstorey plant species were recorded. Germination of soil-stored seeds occurred for three months, and seedling identification occurred on a weekly to fortnightly basis. Following species identification, life history traits were collected including: origin (native or exotic), life form, dispersal mechanism, seed size, successional stage, and whether species were recruited to the rehabilitated sites. Non-parametric tests, Kruskal-Wallis ANOVA and Mann-Whitney U-tests were used to determine whether differences occurred between sites in number of seeds, number of species, or life history traits. Spearman's Rank Correlation Coefficient identified positive and negative associations among life history traits. A total of 10,938 seeds germinated from the 17 study sites, and 10,226 were exotic. Exotics represented 328 germinants and 40 species of remnant rainforest sites; 4,864 germinants and 34 species of adjacent rehabilitated sites; and 5,034 germinants and 31 species of isolated rehabilitated sites. There were no significant differences in number of exotic seeds and species between the adjacent and isolated rehabilitated sites, which indicate that distance from seed source did not affect the exotic composition of rehabilitated sites. The exotic species found in the soil seed banks were herbs and grasses. Herbs and grasses had a significant positive correlation with wind dispersal, small sized seeds, and early successional species. A total of 238 seeds were native recruits. Native recruits represented 120 germinants and 20 species of remnant rainforest sites, 33 germinants and 5 species of adjacent rehabilitated sites, and 85 germinants and 4 species of isolated rehabilitated sites. There were no significant differences in native recruit germinants among the remnant rainforest sites, the adjacent rehabilitated sites and the isolated rehabilitated sites; however, there were significant differences in the number of native species recruited between the three rainforest site types. There were significantly more species recruited to the remnant rainforest sites than the adjacent rehabilitated sites. However, the results indicate that location of rehabilitation planting (adjacent or isolated) does not affect native species recruitment. The native recruited species were shrubs and trees. There was a significant positive association between life form and wind dispersal, small sized seeds, and early successional stage. The soil seed bank composition suggests that 10 – 12 years following weed control, exotic species may germinate after a disturbance and establish the rehabilitated sites. These results have significant implications for future rehabilitation efforts on the Atherton Tableland due to evidence of exotic herbaceous dominance, which requires longer and more intense management.

Sugarcane is a tropical plant grown for sugar production under a wide range of mainly warmer climates throughout the world whereas under temperate climates sugar beet is grown for sugar production. In Australia, sugarcane is grown predominantly in the tropical and subtropical regions of the east coast. Since 1996 there has been a rapid expansion of sugarcane production in the Mareeba-Dimbulah Irrigation Area (MDIA), which is part ofthe Atherton Tableland region, about 50 km inland from Cairns in north Queensland. The expansion has been due to declining sugar yields from sugarcane grown on the coast, several years of devastating storms and cyclones, population growth of Cairns taking up cane land for residential use and the availability of land and water in the MDIA. A major effect of this rapid expansion of sugarcane in the MDIA has been on the availability, supply and cost of irrigation water and the efficiency of water use has become an important issue for growers. This study investigates the potentia for sugar beet to be included into the cropping options of both established sugarcane farmers and other producers in the MDIA. As sugar beet has never been grown in the MDIA (and not commercially in Australia since the 1930 's) a number ofexperiments were conducted to provide yield information under local conditions. Variety trials studied the performance ofa number ofvarieties used in the main sugar beet growing areas ofthe UK, Europe and the USA. Results showed little difference in sugar yield between varieties which were in the range found under commercial production overseas (1012 t/ha). Nitrogen, irrigation and population experiments at two sites (Southedge and Walkamin) in1999 studied the effects of these inputs on sugar beet growth and yield. At Southedge the amount ofapplied nitrogen was having the greatest effect on root yield with 180 kg/ha N giving the highest sugar yield (13.9 t/ha) while the amount of irrigation and population level were less influential. At 180 kg/ha of N, water use efficiency (WUE) was 11.8 and 2.3 t/ML for root and sugar yield respectively in comparison to an estimated sugarcane WUE in the MDIA ofabout 8 and 1.5 t/MLfor cane and sugar yield. At Walkamin it was population level that was having the greatest effect with 100,000 plants/ha giving very high root yields (>100 t/ha) however the sucrose concentration was much less compared to Southedge and so sugar yields were not as high as may have been expected but still higher than Southedge (about 16 t/ha). Water use was about 50 % more on the heavier soil at Walkamin compared to Southedge with 100,000 plants/ha giving an average WUE of12.7 and 1.8 t/ML for root and sugar yield respectively. Growth analysis studies at Southedge showed that radiation would not be limiting to dry matter production, with the excess radiation increasing water use. At Walkamin dry matter production was related to plant population and a higher radiation use efficiency at Walkamin compared to Southedge. An economic study using simple gross margin analysis and yield data from the Southedge trial showed that sugar heet could be a profitable crop in the MDIA however at the current low world sugar prices commercial production is unlikely.