As climate change affects everything from human health to agriculture, plant scientists are trying to cope with a future that might thwart the task to which they have devoted themselves for decades -- saving all the species of the planet's biological diversity. Although climate change has been identified as a direct contributor to the extinction of only a few species of flora and fauna so far, plant scientists fear that may soon accelerate. ''We may lose 30 percent of the plants by 2050,'' says Kathryn Kennedy, executive director of the nonprofit Center for Plant Conservation in
Others predict even higher losses. A temperature increase of 2 to 3 degrees Fahrenheit -- considered a mid-range rise, neither the highest nor lowest prediction -- could wipe out 22 to 75 percent of plant species by 2050, a team of 19 ecologists wrote in the journal Nature in 2004.
…. ''I think of rare species as canaries in the coal mine,'' says Joyce Maschinski, who heads Fairchild's