Question Earthority!

“Ranges may decrease sharply if trees cannot disperse in altered conditions The most extensive and detailed study to date of 130 North American tree species concludes that expected climate change this century could shift their ranges northward by hundreds of kilometers and shrink the ranges by more than half. The study, by Daniel W. McKenney of the Canadian Forest Service and his colleagues, is reported in the December issue of BioScience. McKenney’s study is based on an extensive data-gathering effort and thus more comprehensive than studies based on published range maps. It includes data from Canada as well as from the United States. Observations of where trees are found are used to define the ‘climate envelope’ of each species.” (12/03/07)