Sustainability requires living within the regenerative capacity of the biosphere. In an attempt to measure the extent to which humanity satisfies this requirement, we use existing data to translate human demand on the environment into the area required for the production of food and other goods, together with the absorption of wastes. Our accounts indicate that human demand may well have exceeded the biosphere's regenerative capacity since the 1980s. According to this preliminary and exploratory assessment, humanity's load corresponded to 70% of the capacity of the global biosphere in 1961, and grew to 120% in 1999.
Resource Type: Journal PapersThe range of information on biodiversity currently available via the Internet is reviewed and its accessibility, usefulness and relevance to biodiversity research and to policy decision making assessed. Commercial and non-commercial databases are reviewed. The future of information via the net is also reviewed, in particular the role of the `Clearing House Mechanism' of the Convention on Biological Diversity and the Biodiversity Conservation Information System.
Resource Type: Journal PapersAssuming no radical transformation in human behavior, we can expect important changes in biodiversity and ecosystem services by 2050. A considerable number of species extinctions will have taken place. Existing large blocks of tropical forest will be much reduced and fragmented, but temperate forests and some tropical forests will be stable or increasing in area, although the latter will be biotically impoverished. Marine ecosystems will be very different from today's, with few large marine predators, and freshwater biodiversity will be severely reduced almost everywhere. These changes will not, in themselves, threaten the survival of humans as a species.
Resource Type: Journal PapersA table is provided of 122 bird species with restricted breeding distributions and for which Nepal may hold significant populations. Habitat threats and population changes are detailed for 33 species for which Nepal may be especially important. The vital importance of Nepal's forests to Nepal's avifauna is emphasised.
Resource Type: Journal PapersSmall local hunting communities in Siberia are very distant from any governmental control. Hunted waterbird species, including globally and regionally threatened species, rely for their well-being on the self regulation of remote hunting communities. Interviewed hunters showed a profound knowledge of Baikal Teal, its population status, and the causes of their past decline. Whether the knowledge is shared by other communities in the region and beyond in Northern Siberia needs verification.
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Our analyses show significant differences between predictions from different models, with predicted changes in range size by 2030 differing in both magnitude and direction (e.g. from 92 loss to 322 gain). We explain differences with reference to two characteristics of the modelling techniques: data input requirements (presence/absence vs. presence-only approaches) and assumptions made by each algorithm when extrapolating beyond the range of data used to build the model. The effects of these factors should be carefully considered when using this modelling approach to predict species ranges. Main conclusions We highlight an important source of uncertainty in assessments of the impacts of climate change on biodiversity and emphasize that model predictions should be interpreted in policy-guiding applications along with a full appreciation of uncertainty.
Resource Type: Journal PapersThe effects of Pleistocene glaciations on the genetic characteristics of the most austral conifer in the world, Pilgerodendron uviferum, were analysed with specific reference to the hypothesis that the species persisted locally in ice-free areas in temperate South America.
Results indicated that Pilgerodendron populations are highly monomorphic, probably reflecting past population bottlenecks and reduced gene flow. Southernmost populations tend to be the least genetically variable and were therefore probably more affected by glacial activity than northern ones. Populations located outside ice limits seem to have been isolated during the glacial period. The presence of centres of genetic diversity, together with the lack of a significant correlation between genetic and geographical distances and the absence of geographical patterns of allelic frequencies at most analysed alleles, may indicate that Pilgerodendron did not advance southward after the last glaciation from a unique northern refugium, but spread from several surviving populations in ice-free areas in Patagonia instead.
Resource Type: Journal PapersThere is an urgent need to evaluate the status of groups of species for conservation purposes. A species' status is indicated by both its distribution and abundance, and the rate at which these components are changing. This information is scarce for many tropical forest species. We produced four measures of status based on locality and habitat data for 25 partridges and pheasants of Southeast Asia.
Resource Type: Journal PapersRuff breeding populations have declined widely and in all habitats across temperate Eurasia. Of an estimated population of 2.2-2.8 million birds, 98% are now confined to habitats in the Arctic tundra.
The emerging picture is that the population has shifted northwards and eastwards and has retreated from the wet grassland habitats formerly occupied along the southern edges of its range. It is suggested that the causes are probably of a global nature and may be linked with climate change. It is unclear whether the total population has declined or only shifted north and east. More co-ordinated and systematic monitoring of breeding and wintering populations will be necessary before a full understanding of these changes can be reached.
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