New maps identify global conservation priorities

July, 2013 — A chief aim of conservation is prevention of extinctions and, more broadly, the preservation of biological diversity. Because species are very unevenly distributed across landscapes and seascapes, scientists have looked to see where species are concentrated in order to prioritize conservation efforts. A new study published in the Proceedings of the National Academy of Sciences (PNAS) has made a significant contribution to this effort for terrestrial ecosystems.

The study used geographic range data on mammals, birds and amphibians to produce maps of species richness for each of these groups on a much finer grained geographic scale (10 km X 10 km) than has been done in the past. Maps show where species are concentrated within each taxon for (i) all species; (ii) officially threatened species; and (iii) small-range species. The authors emphasize the usefulness of the last, in that small-range species are most at risk. Priority areas for different vertebrate taxa largely do not overlap, but when combined, the striking finding was that the areas of high diversity of small-ranged vertebrates cover 8% of the world's land area and include an astounding 93% of all vertebrate species. Thus, protecting less than ten percent of land could protect almost all species of birds, mammals and amphibians. In reality, however, less than 20% of these areas is now protected and only about 10.2% is strictly protected.

These maps confirm that tropical regions are overwhelmingly the most important regions for biodiversity conservation. But when it comes to pinpointing priority areas within the tropics, the maps differ substantially from those produced in Norman Myers' famous "hotspots" analysis in 1988 and 1990. That work used data on plant diversity within ecoregions along with information on habitat loss. The authors hope that advances in the fine-scale mapping of the diversity of plants and insects (a hugely diverse and important group) will enable a more comprehensive assessment in future.   Further info