the VOA Special English Agriculture Report.
has more than two thousand kinds of plants that are not found anywhere else. A
new study says climate change could severely affect these plants by the end of
could move northward and toward the Pacific coast in reaction to rising
temperatures and changes in rainfall. Others might climb up mountains to find
the cooler climates they like.
But David Ackerly at the University of
California, Berkeley, says the speed of climate change is greater than during
ice ages in the past. He says plants that cannot move fast enough are in danger
of getting killed off before they can relocate. Changes in plants could also
affect animals that depend on the plants for food.
forty percent of all native plants in California are endemic, meaning they are
found only in that state. The new study says that for two out of three endemic
plants, the areas where they are found could shrink by more than eighty
percent. That, they say, is the worst possible case.
The researchers point out that there are
many things they cannot be sure about. That includes how much warming to expect
in the future from releases of heat-trapping greenhouse gases. Also, they
cannot be sure what will happen to individual species of plants.
they say California's coastal redwood trees, for example, could move farther
north. California oak trees could disappear from the central part of the state.
Professor Ackerly says established trees could survive, but seedlings would not
grow. Oaks could move to cooler weather in the Klamath Mountains along the
border with Oregon.
Central Valley of California could become the new home for plants now found in
the Sonoran desert of Mexico.
study says people who protect or manage natural areas will need to plan for the
possible movement of so-called refugee plants. The researchers identified
places around California where large numbers of plants hit hardest by climate
change are expected to relocate.
they say many of these areas are already under increasing pressure from
development. They say it is not too early to prepare for helping plants
re-establish themselves in new areas.
Berkeley study also involved researchers from Duke University and other
schools. The findings can be read online in PLoS One, a journal published by
the Public Library of Science.
that's the VOA Special English Agriculture Report, written by Jerilyn Watson.
I'm Bob Doughty.