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Tundra disturbance studies, 1: long-term effects of vehicles on species richness and biomass
Selected abstracts on a regular basis. The present reserve system provides good cover and an excellent food base; the potential for population increase is good. Nepal needs to develop policy to handle human/elephant conflicts so that public support for protection of elephant populations can be maintained. -from Authors
Optimal translocation strategies for saving the black rhino J . W . Hearne & J. Swart, Ecological Modelling, 59(3-4), 92Z/00035
1991, pp 279-292. Over the past 30 yr the Diceros bicornis populations in Africa have dwindled dramatically. To enhance the survival prospects of the species, a national conservation strategy has been developed in South Africa. Its main goal, to formulate and implement policies to increase the southern African rhino population as rapidly as possible, involves translocating animals from areas where the population is approaching the ecological carrying capacity and establishing new viable populations in other suitable reserves. A non-linear differential equation model for a population of black rhino is used with a combination of analytical and numerical techniques to investigate a number of issues relating to the translocation of rhino from well-stocked, high-density areas to low-density areas with small herds or no herds. The model is used to determine the maximum sustainable yield from the well-stocked reserves, and then applied to a newly established population to determine optimal import policies. It is extended to include both an established exporting population and a new understocked importing population. -from Authors 92Z/00036 Social organization in deer: implications for localized management W . F . Porter, N. E. Mathews, H. B. Underwood, R. W. Sage Jr & D. F. Behrend, Environmental Management, 15(6), 1991, pp 809-814. Populations of white-tailed deer Odocoileus virginianus inhabiting many state and national parks and suburban areas have grown to the point that they conflict with human activities. Female white-tailed deer are highly philopatric and female offspring remain near their dams for life. This suggests that a population expands slowly as a series of overlapping home ranges. Incorporating this notion into a model of population growth shows that removal of deer by family unit can potentially alleviate conflicts in localized areas for as much as 10-15 yr. -from Authors 92Z/00037 Conservation prospects for musk deer and other wildlife in southern Qinghai, China R . B . Harris, Mountain Research & Development, 11(4), 1991, pp 353-358. In southern Qinghai Province's Baizha Forest, musk deer Moschus spp have declined in most areas, due primarily to snaring. However, musk deer, as well as blue sheep Pseudois nayaur and white-lipped deer Cervus albirostris populations, in close proximity to Tibetan Buddhist monasteries and some villages are afforded protection from most poaching activities. -from Author
Regional 92Z/00038 Key migratory bird terrestrial habitat sites in the Northwest Territories S. A. Alexander, R. S. Fergnson & K. J. McCormick, Occasional Paper - Canadian Wildlife Service, 71, 1991, 185 pp. Identifies 80 Key Habitat Sites for migratory birds each being a terrestrial area that supports at least 1% of the Canadian population of at least one migratory bird (sub) species. Sites also include marine and freshwater habitats where the value of a terrestrial habitat is intimately linked to the presence of aquatic habitats. The first version of this report appeared in 1984; 20 new sites have been added to the list. Many of the sites recognized in the first edition have been revised, some quite substantially. -from Authors
277
922;/00039 Tundra disturbance studies, 1: long-term effects of vehicles on species richness and biomass B . C . Forbes, Environmental Conservation, 19(1), 1992, pp 48-58. Describes up to two decades of unassisted plant recovery from uncontrolled tracked-vehicle disturbance within tundra meadows on two physiographically distinct high-arctic coastal lowlands. Although they exhibit similar vascular floristics, the undisturbed vegetation communities of the two sites differ greatly in terms of the abundance of dominant species. In particular, Salix spp. characterize the larger, more mesic hummocks of the Baffin Island site, while Cyperaceae characterize the more level and generally wetter meadows on Devon Island. Despite these differences, both vascular and cryptogamic species richness are consistently reduced under a variety of low-intensity disturbance regimes in different vegetation-types. Total vascular biomass is significantly reduced in 88% of all stands. Reductions are most severe among woody species; in cases where the biomass of monocotyledons was increased, these increases were more than offset by the losses among dicotyledons. This is contrary to the situation in mesie low-arctic meadows, where significant biomass increases among graminoids have more than offset losses among dicotyledons after less than eight growing-seasons. Even after 18-20 yr, seedling establishment by dicotyledons is virtually lacking in multi-pass tracks, and is limited to only the driest microsites (hammock tops and sides) in single-pass tracks. The few colonists are mostly slow-growing, woody species and are not likely to recover to predisturbance levels of biomass in mesic sites in the foreseeable future. -from Author
92Z/00040
Responding to potential impacts of climate
change on US coastal biodiversity W.V. Reid & M. C. Trexler, Coastal Management, 20(2), 1992, pp 117-142. Accelerated rates of sea level rise and other impacts of climate change resulting from global warming are likely to aggravate threats to coastal biodiversity in the USA. Species restricted to or dependent upon a narrow band of habitat close to sea level will be subjected to continuing threats of development from above, and rising sea levels from below. In five states alone, almost 500 rare and imperilled species utilize the coastal fringe below the 10-ft contour. Some 53 species federally listed as threatened or endangered or as candidates for listing are found only within the narrow band below the 10-ft contour. Rising seas will stress coastal habitats including wetlands, barrier islands, coral reefs, and mangroves, in some cases substantially reducing their area. Steps must also be taken quickly to establish coastal zone policies that allow adaptive response to rising seas by making way for the shoreward movement of caostal ecosystems as sea level changes. -from Authors 92Z/00041
What sustainable agriculture means for
fish and wildlife L. R. Jalm & E. W. Schenck, Journal of Soil & Water Conservation, 46(4), 1991, pp 251-254. Outlines the benefits to wildlife of provisions in the 1985 and 1990 US farm Bills which stress sustainable farming practices. The paper discusses the significance of a variety of legislative changes, namely: water quality protection; integrated farm management; sustainable agricultural research and extension; state technical committees; state and private forestry; and multiyear set-asides. -P.Haxdiman
Minimizing contamination hazards to waterbirds using agricultural drainage evaporation ponds 92Z/00042
D. F. Bradford, L. A. Smith, D. S. Drezner & J. D. Shoemaker, Environmental Management, 15(6), 1991, pp 785-795. In much of the San Joaquin Valley, California, inadequate drainage of applied irrigation water and accumulating salts in the soil have necessitated installation of subsurface tile drainage systems to preserve crop productivity. These subsurface drainage waters axe disposed of by means of evaporation ponds or discharges into the San Joaquin River.
Optimal translocation strategies for saving the black rhino J . W . Hearne & J. Swart, Ecological Modelling, 59(3-4), 92Z/00035
1991, pp 279-292. Over the past 30 yr the Diceros bicornis populations in Africa have dwindled dramatically. To enhance the survival prospects of the species, a national conservation strategy has been developed in South Africa. Its main goal, to formulate and implement policies to increase the southern African rhino population as rapidly as possible, involves translocating animals from areas where the population is approaching the ecological carrying capacity and establishing new viable populations in other suitable reserves. A non-linear differential equation model for a population of black rhino is used with a combination of analytical and numerical techniques to investigate a number of issues relating to the translocation of rhino from well-stocked, high-density areas to low-density areas with small herds or no herds. The model is used to determine the maximum sustainable yield from the well-stocked reserves, and then applied to a newly established population to determine optimal import policies. It is extended to include both an established exporting population and a new understocked importing population. -from Authors 92Z/00036 Social organization in deer: implications for localized management W . F . Porter, N. E. Mathews, H. B. Underwood, R. W. Sage Jr & D. F. Behrend, Environmental Management, 15(6), 1991, pp 809-814. Populations of white-tailed deer Odocoileus virginianus inhabiting many state and national parks and suburban areas have grown to the point that they conflict with human activities. Female white-tailed deer are highly philopatric and female offspring remain near their dams for life. This suggests that a population expands slowly as a series of overlapping home ranges. Incorporating this notion into a model of population growth shows that removal of deer by family unit can potentially alleviate conflicts in localized areas for as much as 10-15 yr. -from Authors 92Z/00037 Conservation prospects for musk deer and other wildlife in southern Qinghai, China R . B . Harris, Mountain Research & Development, 11(4), 1991, pp 353-358. In southern Qinghai Province's Baizha Forest, musk deer Moschus spp have declined in most areas, due primarily to snaring. However, musk deer, as well as blue sheep Pseudois nayaur and white-lipped deer Cervus albirostris populations, in close proximity to Tibetan Buddhist monasteries and some villages are afforded protection from most poaching activities. -from Author
Regional 92Z/00038 Key migratory bird terrestrial habitat sites in the Northwest Territories S. A. Alexander, R. S. Fergnson & K. J. McCormick, Occasional Paper - Canadian Wildlife Service, 71, 1991, 185 pp. Identifies 80 Key Habitat Sites for migratory birds each being a terrestrial area that supports at least 1% of the Canadian population of at least one migratory bird (sub) species. Sites also include marine and freshwater habitats where the value of a terrestrial habitat is intimately linked to the presence of aquatic habitats. The first version of this report appeared in 1984; 20 new sites have been added to the list. Many of the sites recognized in the first edition have been revised, some quite substantially. -from Authors
277
922;/00039 Tundra disturbance studies, 1: long-term effects of vehicles on species richness and biomass B . C . Forbes, Environmental Conservation, 19(1), 1992, pp 48-58. Describes up to two decades of unassisted plant recovery from uncontrolled tracked-vehicle disturbance within tundra meadows on two physiographically distinct high-arctic coastal lowlands. Although they exhibit similar vascular floristics, the undisturbed vegetation communities of the two sites differ greatly in terms of the abundance of dominant species. In particular, Salix spp. characterize the larger, more mesic hummocks of the Baffin Island site, while Cyperaceae characterize the more level and generally wetter meadows on Devon Island. Despite these differences, both vascular and cryptogamic species richness are consistently reduced under a variety of low-intensity disturbance regimes in different vegetation-types. Total vascular biomass is significantly reduced in 88% of all stands. Reductions are most severe among woody species; in cases where the biomass of monocotyledons was increased, these increases were more than offset by the losses among dicotyledons. This is contrary to the situation in mesie low-arctic meadows, where significant biomass increases among graminoids have more than offset losses among dicotyledons after less than eight growing-seasons. Even after 18-20 yr, seedling establishment by dicotyledons is virtually lacking in multi-pass tracks, and is limited to only the driest microsites (hammock tops and sides) in single-pass tracks. The few colonists are mostly slow-growing, woody species and are not likely to recover to predisturbance levels of biomass in mesic sites in the foreseeable future. -from Author
92Z/00040
Responding to potential impacts of climate
change on US coastal biodiversity W.V. Reid & M. C. Trexler, Coastal Management, 20(2), 1992, pp 117-142. Accelerated rates of sea level rise and other impacts of climate change resulting from global warming are likely to aggravate threats to coastal biodiversity in the USA. Species restricted to or dependent upon a narrow band of habitat close to sea level will be subjected to continuing threats of development from above, and rising sea levels from below. In five states alone, almost 500 rare and imperilled species utilize the coastal fringe below the 10-ft contour. Some 53 species federally listed as threatened or endangered or as candidates for listing are found only within the narrow band below the 10-ft contour. Rising seas will stress coastal habitats including wetlands, barrier islands, coral reefs, and mangroves, in some cases substantially reducing their area. Steps must also be taken quickly to establish coastal zone policies that allow adaptive response to rising seas by making way for the shoreward movement of caostal ecosystems as sea level changes. -from Authors 92Z/00041
What sustainable agriculture means for
fish and wildlife L. R. Jalm & E. W. Schenck, Journal of Soil & Water Conservation, 46(4), 1991, pp 251-254. Outlines the benefits to wildlife of provisions in the 1985 and 1990 US farm Bills which stress sustainable farming practices. The paper discusses the significance of a variety of legislative changes, namely: water quality protection; integrated farm management; sustainable agricultural research and extension; state technical committees; state and private forestry; and multiyear set-asides. -P.Haxdiman
Minimizing contamination hazards to waterbirds using agricultural drainage evaporation ponds 92Z/00042
D. F. Bradford, L. A. Smith, D. S. Drezner & J. D. Shoemaker, Environmental Management, 15(6), 1991, pp 785-795. In much of the San Joaquin Valley, California, inadequate drainage of applied irrigation water and accumulating salts in the soil have necessitated installation of subsurface tile drainage systems to preserve crop productivity. These subsurface drainage waters axe disposed of by means of evaporation ponds or discharges into the San Joaquin River.