Islands top global list of places to be protected

WASHINGTON, May 12 (Xinhua) -- Compared with other ecological communities, islands on Earth are the hottest spots with the most unique species and top the global list of places to be protected, a new study by U.S. and German researchers has found.

Compared with other ecological communities, islands on Earth are the hottest spots with the most unique species and top the global list of places to be protected
Compared with other ecological communities, islands on Earth
are the hottest spots with the most unique species and top 
the global list of places to be protected.(File photo)

Although islands account for less than 4 percent of the Earth's land area, they harbor nearly a quarter of the world's plants, including more than 70,000 species that do not occur on mainlands. Vertebrate land animals broadly follow the same pattern.

"Islands are important ... any global conservation strategy wouldn't make any sense if you didn't include the islands," biologist Holger Kreft of the University of California, San Diego, said.

Kreft and his colleagues used a measure of biodiversity that weighted rare species occurring on islands to those on mainlands.

They carved the terrestrial realm into 90 biogeographic regions, calculated biodiversity for each, then compared island and continental ecosystems.

By this measure, island populations of plants and vertebrate animals were found to be eight to nine times as rich.

Their results, plotted on global maps, was reported in the May 12 issue of the Proceedings of the National Academy of Sciences.

Threats to biodiversity may also rise faster for islands than for mainlands, the team reported.

Scenarios based on a measure of human impact projected to the Year 2100 warn that life on islands will be more drastically affected than mainland populations.

The researchers also considered future challenges posed by climate change and reported mixed impacts.

Rising sea levels will swamp low-lying areas and smaller islands, but oceans are expected to moderate island climates by buffering temperature changes.

Editor: Yang Jie | Source: Xinhua