'Carbon starvation' killing trees globally
By GAYATHRI VAIDYANATHAN of ClimateWire
Published: January 15, 2010 Tree death rates could increase globally because of rising temperatures and prolonged droughts linked to climate change, according to multiple studies. The reasons for tree mortality in a warmer, drier world have been narrowed down to three main scenarios — greater prevalence of insects and diseases in a warmer world, the drying out of plants, and a third mechanism where water-stressed trees stop photosynthesizing, called carbon starvation. While researchers are still debating the relative merits of the three, scientists from Los Alamos National Laboratory have pointed to the last scenario as the most relevant for tree mortality. Researchers have made a concerted effort over the past few years to document tree deaths around the world. With climate models predicting up to a 4-degree-Celsius increase in global temperatures in the coming years, the impact of warmer weather on forests is unknown. “It is likely that overall warmer temperatures, together with drought, has the potential to kill trees,” said Craig Allen, an ecologist with the U.S. Geological Survey. The ability of plants to absorb carbon dioxide from the atmosphere is a vital component in global climate change talks because forests act as natural sinks that trap carbon from the atmosphere. Tree death episodes have been noted on all continents since the 1970s because of seasonal and longer-term droughts, according to a recent study co-authored by Allen. The atlas cedar has declined markedly in North Africa following extreme drought. In Russia, 76 million hectares (187.8 million acres) of forests have been labeled as having high risk of health problems. In the United States, pine trees have declined across millions of hectares, and their mortality has been linked to droughts, according to the study. …
New Studies Point to ‘Carbon Starvation’ as a Cause for Tree Mortality
No, no and no!!
Long-term dryness and especially lack of snowpack will kill trees. But those trees that have plenty of water are dying too! It's the freaking, atmosphere, people. They are starved of CO2 because their foliage is damaged by ozone – and their immune systems are compromised because the soils are depleted of essential nutrients by acid rain.
Thought we'd hear from you on this one!