Study:
Hotter weather will shrink Calif. plant habitat
BERKELEY (AP) — As much as
two-thirds of California’s native plants could lose most of their current
habitat if temperatures increase sharply over the next century as some climate
scientists predict, according to a new study.
The report by researchers at the UC Berkeley,
Duke University and other institutions projects how global warming could affect
the roughly 2,400 plant species only found in California, including live oak,
blue oak, scrub oak, California bay laurel and whiteleaf manzanita.
Up to 66 percent of the plants would disappear
from 80 percent or more of their present ranges if greenhouse gas emissions
continue to grow at their current rate, according to the study published
Wednesday in the Public Library of Science’s online journal, PLoS One.
But there would be much less impact on the
state’s biodiversity if emissions drop to below 1990 levels by the end of the
21st century, the researchers found.
While plants can respond to changing climate
over thousands of years, 100 years isn’t enough time for most species to adapt
to the dramatic environmental changes predicted by climate models, said David
Ackerly, a UC Berkeley biology professor and a study co-author.
“Our study projects that climate change will
profoundly impact the future of the native flora in California,” Ackerly said. “Plants
are in danger of getting killed off before they can adjust their distributions
to keep pace.”
The researchers project that many species will
shift north and toward the coast in response to rising temperatures and changing
rainfall patterns, while others may move up into the mountains. Regions such as
the northern Sierra Nevada or the Los Angeles basin could lose much of their
native flora.
The study identified areas where large numbers
of plants affected by climate change could relocate and thrive, including the
Santa Lucia Mountains along the Central Coast, the Transverse Ranges separating
the Central Valley from Los Angeles and the San Gabriel Mountains east of Los
Angeles.
The researchers say protecting these regions,
which they call “climate-change refugia,” will be crucial to maintaining the
state’s biodiversity.
“Across the flora, there will be winners and
losers,” said Scott Loarie, a study co-author and Duke University researcher. “In
nearly every scenario we explored, biodiversity suffers — especially if
the flora can’t disperse fast enough to keep pace with climate change.”
Surface temperatures rose almost 1½
degrees Fahrenheit in the past century, but much of that was in the past 50
years, according to NASA.
Eleven of the past 12 years are the warmest since accurate record-keeping
began in 1850.