for National Geographic Magazine
Forty million years ago the dawn redwood was among the most abundant tree species growing in the Northern Hemisphere.
Today about 6,000 trees remain in the wild, and all of them are in south-central China.
Dozens of modern plant and animal species share a similar history—once widespread, they are now restricted to the booming Asian country.
China is home to more than 31,500 plant species, about 10 percent of the world's total. Several species, including the dawn redwood and the maidenhair tree—also called ginkgo—are as old as the dinosaurs.
But 20 percent of these plants are at risk of extinction due to human pressures, according to Peter Raven, director of the Missouri Botanical Garden in St. Louis.
"By the end of the century, over half the species in China could be extinct or at the verge of extinction," he said. "That's a very serious problem."
Raven chairs the National Geographic Society's Committee for Research and Exploration. (The National Geographic Society owns National Geographic News.)
The committee has funded more than a dozen grantees, many of them Chinese, to perform botanical studies in China.
(Take a video tour of China's unique plants with Peter Raven.)
Changing climates over the past 15 million years failed to wipe out China's rich flora, said Jun Wen, a botanist and expert on Chinese flora at the Smithsonian Institution in Washington, D.C.
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