27 Nov 2012:
Pine Beetle Attacks Cause
Temperature Rise in Canadian Forests
The decimation of trees by mountain pine beetles in British Columbia has caused air temperatures in affected areas to climb by an average of 1 degree Celsius
during the summer months, according to a new
study. In an analysis of satellite and forest data collected between 1999 and 2010, scientists from the University of Toronto and University of California, Berkeley calculated that areas hit hardest by widespread pine beetle infestations
have experienced even sharper temperature increases of several degrees Celsius, as regions are increasingly deprived of the natural cooling effect of trees. Since the evaporation of water through leaves prevents some of the sun’s radiation from heating the ground surface, the widespread loss of trees causes the temperature increases, said Holly Maness, a researcher at UC Berkeley and co-author of the study, published in the journal Nature Geoscience
. And because warming temperatures and milder winters have helped pine beetles to flourish, these infestations are creating a feedback effect that is making the forests even more vulnerable. According to scientists, mountain beetles have affected 66,000 square miles in British Columbia, or 20 percent of the province’s total area.