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The Wog Wog habitat fragmentation experiment
Selected abstracts
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ping project of woodland areas which potentially include rare and endangered species. Long-time continuity of different substrates (eg dead wood) and continuity in treecover are some of the basic criteria to evaluate sensitive woodland ecosystems of high biological quality. -English summary 93Z/00040 The Wog Wog habitat fragmentation experiment C. R. Margules, Environmental Conservation, 19(4), 1992, pp 316-325. An experiment to study the effects of habitat fragmentation on biological diversity was begun in an Eucalyptus forest in SE New South Wales. The two hypotheses which are being tested are 1) that habitat fragmentation reduces biological diversity, and 2) that the reduction in diversity is fragment-size dependent. Axaneae, Phalangida, Formicidae, Scorpiouidae, Diplopoda, Coleoptera, and vascular plants, are the main groups of organxsms" involved in the expernnent. -from Author 932;/00041 Environmental effects of flow regulation on the lower River Murray, Australia K. F. Walker & M. C. Thoms, Regulated Rivers: Research & Management, 8(1-2), 1993, pp 103-119. Regulation has limited exchanges between the river and its floodplain, changed the nature of the littoral zone and generally created an environment inimical to many native species, notably fish. The key to rehabilitation may be to restore a more natural balance of low and medium fows, but this may be unrealistic given the needs of irrigators and other water users. -from Authors 93Z/00042 Causes of land-bird extinctions in French Polynesia R. Seitre & J. Seitre, Oryx, 26(4), 1992, pp 215-222. As well as hunting and habitat destruction, introduced predators ~play a major role in bird population declines and exUncnons, with roof rat Rattus rattus being the most dangerous. Rapid action to eradicate introduced predators, coupled with translocations, would be the most effective way to ensure survival of the remaining bird species. -from Authors
Restoration ecology 93Z/00043 The feasibility of tree planting on landfill containment sites C. S. Crook, Arboricultural Journal, 16(3), 1992, pp 229-241. The effects of anaerobic conditions and localised hots~pots on the successful establishment of trees may aLso be sxgnificant as well as problems associated with the waterlogging and drought conditions commonly occurring on resotred sites. With adequate planning and apporpriate management regimes, successful tree planting and afforestation could be undertaken at relatively low cost. Recommendations are made for planting according to individual site conditions and tree rooting depths. -from Author 93Z/00044 Long-term survival of 20 selected plant accessions in a Rush Valley, Utah, planting R . L . Pendleton, N. C. Frischknecht & E. D. McArthur, Research Note - US Department of Agriculture, Forest Service, INT-403, 1992, 7 pp. Fifty-two plants each of 20 plant accessions were transplanted onto a salt-desert shrub site. Nine of the 20 kinds of plants; five accessions (four species) of Atriplex, two varieties of Kochia prostrata, Sarcobatus vermiculatus, and one species of Yucca, showed generally good survival (>60%r) through the first six years following planting. Only K. prostrata and S. vermicuiatus showed good survival for the full 12-yr period. Large grasshopper populations, a high water table, and other factors Ftkely contributed to shrub mortafity during 1984-89. By 1989, seedlings of both varieties of K. prostrata had spread .throughout the exclosure, up to 5m from the original plantmg area. -from Authors
93Z/00045 Flow rel[ulation and restoration of Florida's Kissimmee River L . A . Toth, J. T. B. Obeysekera, W. A. Perkin~ & M. K. Loftin, Regulated Rivers: Research & Management, 8(1-2), 1993, pp 155-166. Reintroduction of flow through remnant river channels roved river channel habitat diversity and led to favourresponses by fish and invertebrate communities. However, more complete restoration of biological attributes will require the re-establishment of historical inflow characteristics. Current flow characteristics preclude effective river restoration by contributing to chronic low dissolved oxygen regimes, and rel~..titive fish kill~,., interferin, g with fish reproduction and limiting floodp!~n inundation. -from Authors 93Z/00046 Reed canarygrass survival under cyclic inundation J . S . Rice & B. W. Pinkerton, Journal of Soil & Water Conservation, 48(2), 1993, pp 132-135. Phalaris arundinacea, commonly used as a conservation grass, can withstand flooding and is somewhat drought tolerant. Plant species grown to control erosion at pumped storage reservotrs must withstand cyclic inundation, typically on a weekly basis. Reed canarygrass survived inundation of up to two days/week and, in some situations, was able to survive a thirdday. Other factors such as depth of inundation and inundation at different growth stages, especiafty when dormant, need study before reed canarygrass is recommended for use in these reservoirs. -from Authors 932:/00047 Mycorrhizas and other specialised nutrient-acquisition strategies: their occurrence in woodland plants from Kakadu and their role in rehabilitation of waste rock dumps at a local uranium mine P. Reddell & A. R. Mftnes, Australian Journal of Botany, 40(2), 1992, pp 223-242. Over 90% of the woodland flora had one or more specialised nutrient-gathering mechanism. Mycorrhizas were found on 82% of the species, with 16% of species having both ecto and VA mycorrhizas, often on the same individual plant. Many of these observations are the first records of mycorthizal infection in the particular genera and species involved. Rhizobia and mycorrhizal fungi were ubiquitous components of the soft biota in all undistud~ed woodland soils, but they were absent or poorly represented in the stockpiled topsoils and in some of the rudimentary softs formedin waste rock at the mine site. The diversity of spore types and/or numbers of infective propagules of VAM fungi was lower in stockpiled topsoils and in minesofts than in the undisturbed woodland softs. Acute deficiency of P, and to a lesser extent N, was a limitation to growth of seedlings on all softs. Zn deficiency was detected in the only soil for which this was examined. Inoculation of Acacia holosericea seedlings with rhizobium could completely alleviate the efects of N deficiency. Under conditions of both N and P deficiency, dual incoulation of A. holosericea with rhizobium and spores of the VAM fungus, Glomus, only partly overcame the limitations of P deficiency on seedling growth. Induction of deficiencies of P and Zn in a second minesoil demonstrated that inoculation of seedlings of Eucalyptus pellitu with spores of the ectomycorthizal fungus, Scleroderma, partly alleviated the effects of both deficiencies. -from Authors
Restoration ecology 93Z/00048 Re-establishing life in restored topsoils ~. Scullion, Land Degradation & Rehabilitation, 3(3), 1992, pp 161-168. Removal, storage and reinstatement of topsoil disrupts normal biological functions and can markedly change the environment within which soft organisms must exist. This has implications for soft fertility and for the overall ecology of replaced land. The extent and duration of any adverse effect.varies from one group of organhms to anomer a ocommg to their vulnerability to damage, their capaca~, .for recovery and their ability to recolouize areas xrom winch they have been eliminated. Three groups of organisms (earthworks, aerobic bacteria and vesicular
86
ping project of woodland areas which potentially include rare and endangered species. Long-time continuity of different substrates (eg dead wood) and continuity in treecover are some of the basic criteria to evaluate sensitive woodland ecosystems of high biological quality. -English summary 93Z/00040 The Wog Wog habitat fragmentation experiment C. R. Margules, Environmental Conservation, 19(4), 1992, pp 316-325. An experiment to study the effects of habitat fragmentation on biological diversity was begun in an Eucalyptus forest in SE New South Wales. The two hypotheses which are being tested are 1) that habitat fragmentation reduces biological diversity, and 2) that the reduction in diversity is fragment-size dependent. Axaneae, Phalangida, Formicidae, Scorpiouidae, Diplopoda, Coleoptera, and vascular plants, are the main groups of organxsms" involved in the expernnent. -from Author 932;/00041 Environmental effects of flow regulation on the lower River Murray, Australia K. F. Walker & M. C. Thoms, Regulated Rivers: Research & Management, 8(1-2), 1993, pp 103-119. Regulation has limited exchanges between the river and its floodplain, changed the nature of the littoral zone and generally created an environment inimical to many native species, notably fish. The key to rehabilitation may be to restore a more natural balance of low and medium fows, but this may be unrealistic given the needs of irrigators and other water users. -from Authors 93Z/00042 Causes of land-bird extinctions in French Polynesia R. Seitre & J. Seitre, Oryx, 26(4), 1992, pp 215-222. As well as hunting and habitat destruction, introduced predators ~play a major role in bird population declines and exUncnons, with roof rat Rattus rattus being the most dangerous. Rapid action to eradicate introduced predators, coupled with translocations, would be the most effective way to ensure survival of the remaining bird species. -from Authors
Restoration ecology 93Z/00043 The feasibility of tree planting on landfill containment sites C. S. Crook, Arboricultural Journal, 16(3), 1992, pp 229-241. The effects of anaerobic conditions and localised hots~pots on the successful establishment of trees may aLso be sxgnificant as well as problems associated with the waterlogging and drought conditions commonly occurring on resotred sites. With adequate planning and apporpriate management regimes, successful tree planting and afforestation could be undertaken at relatively low cost. Recommendations are made for planting according to individual site conditions and tree rooting depths. -from Author 93Z/00044 Long-term survival of 20 selected plant accessions in a Rush Valley, Utah, planting R . L . Pendleton, N. C. Frischknecht & E. D. McArthur, Research Note - US Department of Agriculture, Forest Service, INT-403, 1992, 7 pp. Fifty-two plants each of 20 plant accessions were transplanted onto a salt-desert shrub site. Nine of the 20 kinds of plants; five accessions (four species) of Atriplex, two varieties of Kochia prostrata, Sarcobatus vermiculatus, and one species of Yucca, showed generally good survival (>60%r) through the first six years following planting. Only K. prostrata and S. vermicuiatus showed good survival for the full 12-yr period. Large grasshopper populations, a high water table, and other factors Ftkely contributed to shrub mortafity during 1984-89. By 1989, seedlings of both varieties of K. prostrata had spread .throughout the exclosure, up to 5m from the original plantmg area. -from Authors
93Z/00045 Flow rel[ulation and restoration of Florida's Kissimmee River L . A . Toth, J. T. B. Obeysekera, W. A. Perkin~ & M. K. Loftin, Regulated Rivers: Research & Management, 8(1-2), 1993, pp 155-166. Reintroduction of flow through remnant river channels roved river channel habitat diversity and led to favourresponses by fish and invertebrate communities. However, more complete restoration of biological attributes will require the re-establishment of historical inflow characteristics. Current flow characteristics preclude effective river restoration by contributing to chronic low dissolved oxygen regimes, and rel~..titive fish kill~,., interferin, g with fish reproduction and limiting floodp!~n inundation. -from Authors 93Z/00046 Reed canarygrass survival under cyclic inundation J . S . Rice & B. W. Pinkerton, Journal of Soil & Water Conservation, 48(2), 1993, pp 132-135. Phalaris arundinacea, commonly used as a conservation grass, can withstand flooding and is somewhat drought tolerant. Plant species grown to control erosion at pumped storage reservotrs must withstand cyclic inundation, typically on a weekly basis. Reed canarygrass survived inundation of up to two days/week and, in some situations, was able to survive a thirdday. Other factors such as depth of inundation and inundation at different growth stages, especiafty when dormant, need study before reed canarygrass is recommended for use in these reservoirs. -from Authors 932:/00047 Mycorrhizas and other specialised nutrient-acquisition strategies: their occurrence in woodland plants from Kakadu and their role in rehabilitation of waste rock dumps at a local uranium mine P. Reddell & A. R. Mftnes, Australian Journal of Botany, 40(2), 1992, pp 223-242. Over 90% of the woodland flora had one or more specialised nutrient-gathering mechanism. Mycorrhizas were found on 82% of the species, with 16% of species having both ecto and VA mycorrhizas, often on the same individual plant. Many of these observations are the first records of mycorthizal infection in the particular genera and species involved. Rhizobia and mycorrhizal fungi were ubiquitous components of the soft biota in all undistud~ed woodland soils, but they were absent or poorly represented in the stockpiled topsoils and in some of the rudimentary softs formedin waste rock at the mine site. The diversity of spore types and/or numbers of infective propagules of VAM fungi was lower in stockpiled topsoils and in minesofts than in the undisturbed woodland softs. Acute deficiency of P, and to a lesser extent N, was a limitation to growth of seedlings on all softs. Zn deficiency was detected in the only soil for which this was examined. Inoculation of Acacia holosericea seedlings with rhizobium could completely alleviate the efects of N deficiency. Under conditions of both N and P deficiency, dual incoulation of A. holosericea with rhizobium and spores of the VAM fungus, Glomus, only partly overcame the limitations of P deficiency on seedling growth. Induction of deficiencies of P and Zn in a second minesoil demonstrated that inoculation of seedlings of Eucalyptus pellitu with spores of the ectomycorthizal fungus, Scleroderma, partly alleviated the effects of both deficiencies. -from Authors
Restoration ecology 93Z/00048 Re-establishing life in restored topsoils ~. Scullion, Land Degradation & Rehabilitation, 3(3), 1992, pp 161-168. Removal, storage and reinstatement of topsoil disrupts normal biological functions and can markedly change the environment within which soft organisms must exist. This has implications for soft fertility and for the overall ecology of replaced land. The extent and duration of any adverse effect.varies from one group of organhms to anomer a ocommg to their vulnerability to damage, their capaca~, .for recovery and their ability to recolouize areas xrom winch they have been eliminated. Three groups of organisms (earthworks, aerobic bacteria and vesicular