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 Papers
The 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 Papers
There 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 Papers
Ruff 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.Resource Type: Journal Papers
A reduction in forest area should result in a reduction of its number of species and, moreover, do so in a characteristic way according to the familiar species-area relationship. Brooks, Pimm & Collar (1997) applied this formula to the losses in forest area in the Philippines and Indonesia. Independently derived totals of the number of endemic bird species that are threatened with extinction broadly agree with these predicted losses. In some cases, however, predicted losses overestimate or underestimate the actual numbers of threatened species.Resource Type: Journal Papers
Spoon-billed Sandpiper Eurynorhynchus pygmeus is classed as globally Vulnerable, based on the only available population estimate, made in 1977, of 2,000-2,800 pairs. Surveys for breeding Spoon-billed Sandpipers were carried out in summer 2000 on the Anadyr estuary coast, the Chukotka autonomous region, Russia. Although six new breeding sites were found, only 16-17 breeding males/pairs were recorded on the northern coast of the Anadyr estuary and five males/pairs on the southern coast and more southerly lagoons. These numbers were much lower than expected, and the species was not recorded in several apparently suitable areas.Resource Type: Journal Papers
Governments are often accused of responding only to short-term and parochial considerations. It is therefore remarkable that representatives of 190 countries recently committed themselves at the Convention on Biological Diversity to reducing biodiversity loss. This presents conservation biologists with perhaps their greatest challenge of the decade. The authors of this Policy Forum describe approaches to identifying more of the earth's biological diversity; understanding how biological, geophysical, and geochemical processes interact; and presenting scientific knowledge in time to contribute to and achieve the 2010 target.Resource Type: Journal Papers
The forests of eastern Tanzania are a globally important biodiversity hotspot. In this study 361 eastern Tanzanian restricted range forest tree taxa were assessed. Of these taxa, 223 occurred in the Eastern Arc, 150 in Coastal forests, 17 in Northern forests and 21 in the Lake Nyasa forests. The majority of the taxa had restricted elevational ranges with 76.3 occurring in no more than two 200 m elevational bands out of a total potential elevation range of 3000 m. The majority of the taxa occupied a small area in the eastern Tanzanian forests, with 201 taxa being only found at a few sites. In determining priority areas for conservation, selection of taxon definitions can have important effects. For example, tree size varies with elevation, so if only large trees are used then site selection will be biased towards particular areas.Resource Type: Journal Papers
The United Nations List of Protected Areas is an essential reference document for all who want to understand the progress made in responding to the challenges of biodiversity loss and other environmental threats around the world. It is a record of extraordinary human achievement over 125 years - a commitment by nations, peoples, groups and individuals to safeguard areas of land and sea from destruction. Protected areas represent human ideals at their best - they express a long term vision and a broad sense of responsibility towards people and nature.
This version of the list is the twelfth in a series, each recording steady expansion in the total area protected. There are now some 12,754 areas in the UN List, covering almost 8% of the land surface of the world (a far smaller proportion of the oceans is protected). Compared to the previous, 1993 edition of the of the UN List, this report includes 2,933 more sites covering 3.9 million more square kilometres. At the end of the century it can be said that practically every country has protected areas; some have a very sophisticated network of sites.Resource Type: Reports
This study demonstrates the utility of carbon isotope discrimination in describing genetic adaptation to arid environments, although it is probably most useful in detecting differentiation when the strategy of the species under investigation is to increase water use efficiency, rather than drought-avoidance. The results suggest that populations on the eastern and western sides of the Andes should be treated as separate management units for the purposes of conserving the genetic resource of this species.Resource Type: Journal Papers
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