Climate change threatens two-thirds of California’s unique plants, study says - Los Angeles Times

• The state’s plants are at risk of collapse unless they migrate or are moved to refuges, scientists say. Animals may also be separated from plants on which they depend, according to researchers.

  By Margot Roosevelt, Los Angeles Times Staff Writer
  June 25, 2008

• Two-thirds of California’s unique plants, some 2,300 species that grow nowhere else in the world, could be wiped out across much of their current geographic ranges by the end of the century because of rising temperatures and changing rainfall patterns, according to a new study.

  The species that cannot migrate fast enough to higher altitudes or cooler coastal areas could face extinction because of greenhouse gas emissions that are heating the planet, according to researchers.

• Half of the plant species that are unique to the continental United States grow only in the Golden State, from towering redwoods to slender fire poppies. And under likely climate scenarios, many would have to shift 100 miles or more from their current range — a difficult task given slow natural migration rates and obstacles presented by suburban sprawl.
• The study, which was based on more than 80,000 specimens, was hailed as groundbreaking by leading scientists in the field. "It is a timely analysis of the likely fate of the plants of California in the face of climate change," Peter Raven, president of the Missouri Botanical Garden and coauthor of seminal texts on California flora, said in an e-mail.

  And in Southern California, given water shortages and habitat disruption, he added, "lots of the populations are right on the edge. . . . The balance could easily be tipped so we could lose many of them in a very short period of time."

  As California’s unique species migrate, they could be separated from the creatures that pollinate them. Animals could be divided from the plants on which they depend, the researchers noted.

• The state may also have to set aside new refuges and corridors, and prepare to move some plants if necessary. "Planning for plant refugees will become a new but important concept for natural reserves to think about," said biologist Brent Mishler, director of the University and Jepson Herbaria at UC Berkeley, the state’s most important flora collection.
• Native plants often support 10 to 50 times as many species of native wildlife as nonnative plants, and biologist Philip Rundel, a California plant specialist at UCLA, noted that the effects measured by the study "will surely be paralleled by what we can expect to occur with animal species."

  "This article is a wake-up call for all Californians that global change impacts on our environment are more than just a theoretical issue."

  margot.roosevelt@

  latimes.com