Native Plant Of Great Plains May Be Threatened By Climate Change
4, 2001-- A common Great Plains prairie plant, the
partridge pea (Chamaecrista fasciculata), could face severe reduction
in numbers if climate conditions in the Midwest change to the extremes
predicted for the next 25 to 35 years, according to a study to be
published in the Oct. 5 issue of the journal Science.
the partridge pea is threatened by changing conditions, other common
native species may be threatened as well.
partridge pea's ability to adapt to rapidly changing climate conditions
is likely to be much slower than the rate of climate change predicted
for its native habitat throughout the Midwest," said the study's
principal investigator, Julie R. Etterson, a post-doctoral research
associate in biology at the University of Virginia. Etterson was
a Ph.D. student at the University of Minnesota when she conducted
to the climate model used by Etterson for her study, Minnesota's
climate in 25 to 35 years is predicted to be similar to today's
climate in Kansas, which is drier and warmer than Minnesota's. Under
extreme conditions in a worst-case scenario, Minnesota's climate
could become more like current-day Oklahoma -- much drier and warmer.
Etterson's study indicates that native prairie plants could be seriously
threatened if these predictions hold true.
partridge pea's evolutionary response for adaptation to hotter and
drier conditions is unlikely to be fast enough to ensure its survival,"
planted seeds from Minnesota partridge peas in Kansas and Oklahoma.
She also planted Kansas partridge peas in Oklahoma. She found that
seed production of Minnesota plants dropped 84 percent when grown
in Kansas, and 94 percent when grown in the hotter and drier conditions
of Oklahoma. The Kansas partridge pea plants dropped 42 percent
when grown in Oklahoma. She also studied leaf number and leaf thickness,
traits that are important indicators of drought tolerance, and found
that the transplants were less adapted than local plants of the
same species grown in the same plots.
plants in the Midwest are facing two problems that may negatively
affect their future survival," Etterson said. "One, the predicted
rate of climate change is much more rapid than has occurred previously;
and two, the habitat of native plants is fragmented to isolated
islands between farms and cities, making it difficult for plants
to slowly migrate to areas with more favorable conditions. This
means plants will have to rely more on their evolutionary response
to changing conditions. The partridge pea is unlikely to adapt to
changing conditions quickly enough."
emphasizes that her findings are specific to the species she studied,
the partridge pea. "The species could possibly develop some incremental
adaptive responses to climate change during the next 25 to 35 years,
but the responses are unlikely to be rapid enough. Our findings
suggest that we should not assume that plant populations will evolve
fast enough to keep pace with climate change. We may need to think
about alternative management strategies for native species if the
climate predictions prove to be accurate."
Fariss Samarrai, (434) 924-3778