Responses of boreal conifers to climate fluctuations: indications from tree-ring widths and carbon isotope analyses

Spatial distribution and species composition of the boreal forest are expected to change under predicted climate change scenarios. Current research indicates that water limitations control the southern boundary of the central Canadian boreal forest and temperature limitations control the northern boundary. As part of Boreal Ecosystem ? Atmosphere Study (BOREAS), we examined this idea by comparing annual variation in tree-ring widths and carbon isotope ratios (d13C) of tree-ring cellulose with annual climatic parameters in the northern and southern boreal forest.