"In California grasslands, plants control most of the water exiting the system by transpiring water through their leaves until they die," Zavaleta said. "Simulated global warming accelerated the death of the dominant grasses in our plots, leaving slightly more water in the soil for other species like oaks and summer wildflowers to use. This doesn't mean climate change is good for California grasslands, but it reinforces the importance of paying attention to how plants and animals could modify its effects."
"Mediterranean-type ecosystems throughout the world experience similar growing season dynamics to our site and even share some common species as a result of exotic introductions," the authors concluded. "It is reasonably likely that they will respond in qualitatively similar ways to warming."
In the past year, Jasper Ridge scientists have reported other discoveries that run counter to widely held assumptions about global climate change. In a Dec. 2002 study in the journal Science, Field, Zavaleta and their colleagues discovered that excess atmospheric CO2 can retard plant growth instead of increasing it. And in a PNAS study published in June, the researchers found that excess CO2, nitrogen and water caused a significant reduction in the diversity of plant species.