June 25, 2013
June 25, 2013
What region of the world has the most imperiled mammals? Where are the most bird species found? And where are new amphibians being discovered? Indonesia and Malaysia is the answer to the first question; the Amazon, the second; and the Andes, the third. Anew studyin the Proceedings of the National Academy of Sciences (PNAS) has used global data on 21,000 mammals, birds, and amphibians to create magnificent maps that highlight missing priorities for conservation.
"Identifying the most important areas for biodiversity is essential for directing conservation resources. We must know where individual species live, which ones are vulnerable, and where human actions threaten them," explains lead author Clinton Jenkins at North Carolina State University. "We have better data than in the past—and better analytical methods. Now we have married them for conservation purposes."
The result is a series of stunning maps at scales of 10 kilometers by 10 kilometers: 100 times finer than anything ever produced before. The scientists hope that the new maps can point conservationists and policy-makers to new areas for protection—before they are lost. The finer scale is especially important because, according to the paper, it is "comparable with regional decisions on where to place protected areas."
The scientists created a series of maps highlighting different themes, including total diversity within each taxonomic group (mammals, birds, amphibians), threatened species, species dependent on small-ranges (i.e. particularly vulnerable to extinction), and newly discovered species.
Selected priority ecoregions based on small-ranged vertebrates. Maps courtesy of Jenkins et al.Click to enlarge.
The maps found that when combining all the vertebrate species, the most biodiverse areas were the Amazon, southeastern Brazil, and Central Africa. While these regions cover only about 7.2 percent of land area, they contain around half of the world's species.
Looking at diversity of each taxonomic group, the research found that "for birds and mammals, these areas are nearly identical: the moist forests of the Amazon, Brazilian Atlantic Forest, Congo, Eastern Arc in Africa, and the Southeast Asian mainland and islands house the greatest numbers of bird and mammal species. The pattern for amphibians is similar, but amphibians have exceptional diversity in the Neotropics."
Birds and mammals living in small-ranges were located primarily in the Andes, Madagascar, and Southeast Asian islands. Since most amphibians are small-ranged species already, few hotspots were located. However, 93 percent of the world's small-ranged mammals, birds, and amphibians are found in just 8.3 percent of the land area. Some if these areas—such as Papua New Guinea, the eastern coast of Australia, the west Coast of North America, and smatterings of China—are not included in current ecological hotspots designation crafted by Norman Meyers in 1988. The paper concludes that the best way to protect the world's biodiversity is to focus on these highly-diverse small-ranged species hotspots.
In fact, many of the most important sites are currently without protection. According to the paper, currently only one third of the biodiversity centers are protected, and just 11 percent are under strict protection.
"There is a growing worry that we are running out of time to expand the global network of protected areas. Our results can guide this expansion," says co-author Lucas Joppa with Microsoft Research.
Global maps of species richness for different categories of species. The top row shows the richness of all species in the taxon. For birds, we used breeding ranges only. The middle row shows the richness of threatened species (vulnerable, endangered, or critically endangered in the IUCN Red List). The bottom row shows the richness of species whose geographic ranges are smaller than the median range size for that taxon. Maps use a 10 × 10 km grid and the Eckert IV equal-area projection. Maps courtesy of Jenkins et al.Click to enlarge.
CITATION: Clinton N. Jenkins, Stuart L. Pimm, and Lucas N. Joppa.Global patterns of terrestrial vertebrate diversity and conservation. PNAS. 2013.