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61.
Assessment of the conservation status of partridges and pheasants in South East Asia 总被引:3,自引:2,他引:1
The recent compilation of IUCN Action Plans for partridges and pheasants has highlighted the need for locality data to be used in conservation evaluation. Here we used locality data to measure changes in the proportion of localities from which each of 25 South East Asian species has been recorded, changes in their geographic extent and the amount of habitat that is potentially available to them. These are measures that use the data which are most readily available. Single landmass endemics from both montane and lowland forests appear to have fared badly with peacock pheasants Polyplectron and hill-partridges Arborophila suffering particularly large declines, although for montane forest species, these apparent declines are probably the result of relatively less survey effort in highland areas. Species previously widespread that give cause for concern include the green peafowl, Pavo muticus, and the blue-breasted quail, Coturnix chinensis. Conservation priorities include action on behalf of lowland forest specialists, some of which have suffered substantial reductions in the area of habitat that is potentially available. Surveys are required on the hills and mountains of Borneo, the Malay Peninsula and Sumatra, and in the Lesser Sundas. Increased resolution of vegetation data would permit more accurate prediction of species ranges. 相似文献
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PHILIP L. PERKINS 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1970,3(3):301-310
A collection of fossil fish from Fossil Lake, Wyoming (Eocene) was compared with samples from three modern natural lakes and an artificial fish pond. All fish were divided into predators or planktivores. The predators all had higher equitabilities than did the planktivores from the same locality. This suggests that the predators are resource limited (food) and that if migration to and from the lakes is not excessive, the equitability of the predatory forms will eventually stabilize at a higher level than that of the planktivorous forms. The paleontological sample follows this pattern, probably from the same causative factors. 相似文献
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PHILIP C. J. BARKER 《Austral ecology》1991,16(2):149-158
Podocarpus lawrencei is a native conifer which normally occurs as a shrub in alpine, and less often in sub-alpine, communities in New South Wales, Victoria and Tasmania. A disjunct and unusual distribution occurs at Goonmirk Rocks, in north-east Victoria, in a montane, wet forest environment in which P. lawrencei grows as a procumbent and sometimes vertical tree up to 13 m tall. The communities in which P. lawrencei occurs at Goonmirk Rocks are described, and the population structure of P. lawrencei is determined using an age class model. Measurement of light regimes and of the nutrient status of these communities indicate differences between areas of active regeneration and those with none, and between forest types that do support P. lawrencei and those that do not. P. lawrencei is determined to be a stable component of the vegetation of Goonmirk Rocks, where it attains its best development on the margins of cool temperate rainforest where a broken canopy and the long-term absence of fire allow it to develop into a low scrub with simple floristics. A community fire history is reconstructed using the age class model, fire scars and the age of Acacia dealbata. 相似文献
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MATHEW J. COLLINS GERARD MUYZER GORDON B. CURRY PHILIP SANDBERG PETER WESTBROEK 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1991,24(4):387-397
An immunological investigation was conducted of soluble intra-crystalline macromolecules isolated from living and fossil brachiopod shells, which had previously been used for an immunologically based study of phylogeny (serotaxonomy). The soluble intra-crystalline macromolecules comprised 0.03% by weight of the extant shell material. Bulk analysis and gel electrophoresis indicated that the organic material is predominantly glycoprotein, and contains up to 30% by weight carbohydrate. Treatment of the macromolecules with periodate and proteinase K revealed that antibodies were raised predominantly against the carbohydrate moieties. Using a specially adapted dot blot immunobinding assay (DIBA) the decay in immunological signal over geological time was determined. Pleistocene shells have lost between 99 and 99.9% of immunological reactivity, and original antigenic determinants form a declining proportion of total organic matter. It is suggested that condensation reactions between amino acids and sugars account for the rapid destruction of determinants; this has important implications for the direction of future studies on fossil macromolecules. □ Serotaxonomy, biomolecular palaeontology, glycoproteins, melanoidins, brachiopods. 相似文献
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HENRY PLOTKIN 《Biology & philosophy》1997,12(2):281-287
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