Biodiversity hotspots identify conservation priorities
Environmental 'emergency rooms' hold 75 percent of the most threatened mammals, birds, and amphibians
HOUSTON (Feb.2, 2005)– The new book Hotspots Revisited identifies 34 regions worldwide where 75 percent of the planet's most threatened mammals, birds, and amphibians survive within habitat covering just 2.3 percent of the Earth's surface (roughly equivalent to the combined areas of the five largest U.S. states). This habitat originally covered 15.7 percent of the Earth's surface, an area equivalent in size to Russia and Australia combined. The new analysis shows that an estimated 50 percent of all vascular plants and 42 percent of terrestrial vertebrates exist only in these 34 hotspots.
The Madrean Pine-Oak Woodlands, a rugged, mountainous area stretching from Mexico to the Southwestern United States, is one of nine newly identified hotspots. Three other hotspots that extend into U.S. states or territories -- the California Floristic Province, the Caribbean Islands, and Polynesia-Micronesia -- remain under severe threat.
Hotspots Revisited (CEMEX, 2004) contains the results of an in-depth reanalysis of global hotspots, a widely used prioritization strategy for allocating conservation dollars to areas where they can do the most good.
"The biodiversity hotspots are the environmental emergency rooms of our planet. This latest assessment underscores the value of the hotspots concept for defining urgent conservation priorities," said Russell A. Mittermeier, president of Conservation International (CI) and co-editor of the new book. "We must now act decisively to avoid losing these irreplaceable storehouses of Earth's life forms."
Nearly 400 specialists contributed to the four-year-long hotspots reappraisal. Their analysis has resulted in an increase in the number of hotspots from 25 to 34. The East Melanesian Islands Hotspot was added because it had degraded dramatically over the last five years; the Madrean Pine-Oak Woodlands, Japan, Horn of Africa, Irano-Anatolian, Mountains of Central Asia, and Maputaland-Pondoland-Albany (in southern Africa) were added because of newly available data showing they qualify for hotspot status; and the Himalaya and Eastern Afromontane regions have been identified as distinct hotspots in their own right.
The scientists delved beyond species to identify genera and families that are unique to the hotspots, concluding that hotspots also hold a disproportionately high degree of unique evolutionary history. Madagascar and the Indian Ocean Islands Hotspot, for example, has 24 plant and vertebrate families that are found nowhere else on Earth. "We now know that by concentrating on the hotspots, we are not only protecting species, but deep lineages of evolutionary history," Mittermeier said. "These areas capture the uniqueness of life on Earth."
The hotspots concept was pioneered in 1988 by British ecologist Norman Myers, who recognized that hotspot ecosystems (most often in tropical forest areas) cover a small total land area yet account for a very high percentage of global biodiversity. The concept was subsequently refined by Myers and CI, most recently in 2000.
"This new analysis has benefited greatly from increased collaboration among countries and organizations, as well as from scientists' ever-increasing knowledge of species and their habitats," said Gustavo A.B. da Fonseca, executive vice president of CI.
Two factors determine which areas qualify as hotspots: number of endemic species (those found nowhere else) and degree of threat. Plants are used as a measure of endemism, and each of the hotspots holds at least half a percent of the total diversity of vascular plants as endemics; this translates to 1,500 species of vascular plants found exclusively within its boundaries. Degree of threat is determined by the percentage of remaining habitat, with each hotspot having lost at least 70 percent of its original natural habitat. Some of the hotspots have less than 10 percent of their original natural habitat.
THE HOTSPOTS ARE:
- Tropical Andes
- Tumbes-Chocó-Magdalena (Panama, Colombia, Ecuador, Peru)
- Atlantic Forest (Brazil, Paraguay, Argentina)
- Cerrado (Brazil)
- Chilean Winter Rainfall-Valdivian Forests
- Mesoamerica (Costa Rica, Nicaragua, Honduras, El Salvador, Guatemala, Belize, Mexico)
- Caribbean Islands
- California Floristic Province
- Madrean Pine-Oak Woodlands (Mexico, U.S.) (NEW)
- Guinean Forests of West Africa
- Cape Floristic Region (South Africa)
- Succulent Karoo (South Africa, Namibia)
- Madagascar and the Indian Ocean Islands
- Coastal Forests of Eastern Africa
- Eastern Afromontane (NEWLY DISTINCT AND SIGNIFICANTLY EXPANDED)
- Maputaland-Pondoland-Albany (South Africa, Swaziland, Mozambique) (NEW)
- Horn of Africa (NEW)
EUROPE AND AFRICA:
- Mediterranean Basin
- Western Ghats and Sri Lanka (India, Sri Lanka)
- Mountains of Southwest China
- Sundaland (Indonesia, Malaysia, and Brunei)
- Wallacea (Indonesia)
- Himalaya (NEWLY DISTINCT)
- Irano-Anatolian (NEW)
- Mountains of Central Asia (NEW)
- Japan (NEW)
- Southwest Australia
- New Caledonia
- New Zealand
- Polynesia-Micronesia (includes Hawaii)
- East Melanesian Islands (NEW)
The threats to the hotspots include: habitat destruction; invasive species; direct human exploitation of species for food, medicine, and the pet trade; and climate change, which magnifies the effects of habitat destruction and fragmentation.
The latest analysis offers mixed news about existing hotspots. On one hand, some hotspots have deteriorated significantly: a notable example is Southeast Asia's Sundaland, whose forest loss has been driven largely by extensive commercial logging and agricultural projects. On the other hand, relatively little forest has been lost in the Atlantic Forest, and Madagascar looks set to hold steady following President Marc Ravalomanana's recent pledge to triple the size of his nation's protected area network.
"The new hotspots analysis ensures that we will continue to direct conservation funds to the areas where we can have the greatest possible impact," said Peter Seligmann, CEO and chairman of the board of CI. "It also points out the need for additional resources to address the new priority areas that have been identified."
CI already works in most of the existing hotspots and plans to expand its programs into some of the new hotspots, including the Madrean Pine-Oak Woodlands. "We have already begun looking seriously at the U.S.-Mexico border area," Mittermeier said. "We are trying to identify the best ways to leverage scientific knowledge and the expertise of partner organizations to conserve this region for the benefit of not only its plant and animal species, but also for the millions of people whose well-being is tied to its ecological health."
The Madrean Pine-Oak Woodlands hotspot is a 178,095-square-mile area encompassing Mexico's main mountain chains, some isolated mountaintops in Baja California, and a few scattered patches in the southern United States (represented by the Madrean Sky Islands, a series of about 40 mountain-tops in southern Arizona and New Mexico, and other mountaintops in Texas, including part of Big Bend National Park).
This hotspot is home to about 5,300 flowering plant species (of which almost 4,000 are endemics), about a third of the world's oak and pine tree species, and over 1,500 vertebrate species (including 134 endemic species). Among many charismatic flagship species in the region is the volcano rabbit or zacatuche (Romerolagus diazi), one of the world's smallest rabbits, which is found only in the mountains surrounding Mexico City. The hotspot is also home to up to 200 species of butterfly, of which 45 are endemic, and plays host to one of the world's most famous wildlife spectacles, the over wintering mass of monarch butterflies (Danaus plexippus) in the pine forests of Michoacan. Threats to the hotspot include logging and intentional burning to clear land for livestock or agriculture.
Hotspots Revisited was produced by CEMEX, one of the world's largest cement manufacturers, in collaboration with Conservation International, Agrupación Sierra Madre, and the University of Virginia. It was edited by Russell Mittermeier, Gustavo A.B. da Fonseca, Michael Hoffmann, John Pilgrim, Thomas Brooks, Patricio Robles Gil, Cristina G. Mittermeier, and John Lamoreux. The book, which features nearly 300 photographs, also includes contributions from 197 of the specialists who participated in the hotspots reanalysis. The book can be purchased from www.conservation.org .
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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