European plants and climate change

In January I wrote about European birds and climate change. The paper I summarized there projected how the distribution of European birds might change over the next century in response to changes in the European climate. But we don't have to wait to see the effects of climate change. Plant hardiness zones in the United States have moved northward in the last sixteen years, and today there's a paper in Science showing that European plants are moving up the mountains as the climate in Europe gets warmer.

Lenoir and colleagues collated data from almost 4000 floristic surveys in western Europe, spanning the full elevational range from 0 to 2600m above sea level. Using these data they used statistical methods to determine the elevation at which each species was most likely to occur in surveys conducted between 1905 and 1985 (the x-axis in the plot to the left) and in surveys conducted since 1985 (the y-axis). Of the 171 species included in their sample, 46 showed statistically significant shifts in the elevation at which they were most likely to occur. Of those 46, 41 showed an upward shift in elevation. Only 5 showed a downward shift.  "More than two-thirds (118/171) of the species shifted their optima upward, whereas only one-third (53/171) shifted their optima downward." Overall, the elevation at which these species were most likely to occur shifted upward almost 30m per decade - the length of an American football field since 1985.