The threat posed to coral reefs by biological invasion is unlikely to diminish and should therefore be considered in analyses of the effectiveness of Marine Protected Areas.
Resource Type: Journal PapersWe briefly review recent global trends in habitat area in as many broadly-defined natural habitats as possible, and in indices of animal populations characteristic of those habitats. The information available indicates continuing declines in habitat area and species, but those data are extremely sparse.
Resource Type: Journal PapersThe number of environmental variables used during modelling could affect the outcome, but we found no correlation between these and our estimates of extinction risk in global samples. Although further investigation is needed, it is unlikely to result in substantially reduced estimates of extinction. Anthropogenic climate change seems set to generate very large numbers of species-level extinctions.
Resource Type: Journal PapersGlobal and regional coral reef area statistics are of considerable value in fields ranging from global environmental change to fisheries to conservation. Although widely quoted, Smith's 1978 figure of 600 000rkm2 is only an approximate calculation. The World Conservation Monitoring Centre has prepared a new estimate of reef coverage by mapping emergent reef crest and very shallow reef systems. These data were rasterised, using 1rkm grid squares, as a means of reducing errors arising from variation in scale. Global and regional reef coverages were calculated from the resultant grid. The total global area is estimated at 255 000rkm2, considerably lower than many previous estimates. Variation in reef area estimates is, in part, a function of variation in reef definition.
Resource Type: Journal PapersDeforestation is a main driver of climate change and biodiversity loss. An incentive mechanism to reduce emissions from deforestation and forest degradation (REDD) is being negotiated under the United Nations Framework Convention on Climate Change. Here we use the best available global data sets on terrestrial biodiversity and carbon storage to map and investigate potential synergies between carbon and biodiversity-oriented conservation.
Resource Type: Journal PapersThe 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 PapersThe countries affected by the 2004 Asian tsunami contain the most diverse and extensive coral reefs and mangroves of the Indian Ocean, and some of the richest in the world. Not only are these ecosystems among the most threatened in the world, they also provide numerous essential ecosystem services.
It is thus not surprising that reefs and mangroves received widespread attention after the tsunami, with three principal questions posed: Are the tsunami's impacts on reefs and mangroves a further threat to their future survival? Did reefs and mangroves play a role in shoreline protection and reduce structural damage and human mortality? How could reconstruction efforts include actions to maintain these ecosystems and reduce further threats to them?
Resource Type: Journal PapersThis 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 PapersCoral reefs are the most biologically diverse of shallow water marine ecosystems but are being degraded worldwide by human activities and climate warming. Analyses of the geographic ranges of 3235 species of reef fish, corals, snails, and lobsters revealed that between 7.2 and 53.6 of each taxon have highly restricted ranges, rendering them vulnerable to extinction. Restricted-range species are clustered into centers of endemism, like those described for terrestrial taxa. The 10 richest centers of endemism cover 15.8 of the world's coral reefs (0.012 of the oceans) but include between 44.8 and 54.2 of the restricted-range species. Many occur in regions where reefs are being severely affected by people, potentially leading to numerous extinctions. Threatened centers of endemism are major biodiversity hotspots, and conservation efforts targeted toward them could help avert the loss of tropical reef biodiversity.
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