Tuesday, April 1, 2008

Global warming bringing early spring seasons to Eurasian forests

Science Daily: With the help of satellite data, researchers from laboratories in France, the UK, Japan and Russia have completed the accurate and large-scale mapping of leaf appearance dates in boreal forests. Their work has revealed a remarkable trend towards earlier foliation, which occurred between 1987 and 1990, over a large part of northern Eurasia, caused by the unprecedented increase in spring temperatures since 1921. By comparing these results with the previous studies available, they were able to reconstruct the foliation trend over the whole 20th century. Their work, published the journal Global Change Biology, enables the effects of global warming on these forests to be measured.

Phenology studies the climate-dependent variations of seasonal phenomena of plant life. In this study, the researchers particularly focused on the date of leaf appearance in boreal forests. In the northern hemisphere at high latitudes, foliation depends essentially on temperature. It is, therefore, considered direct evidence of the warming of the climate observed during the 20th century, which is especially marked in these regions. In addition, it also sets the pace for exchanges of carbon between vegetation and the atmosphere, which have an impact on the climate….

Photo of a boreal forest, NASA, Wikimedia Commons

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