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Species Richness in a Central European Bird Community
Lemoine, N., Bauer, H.-G., Peintinger, M. and Bohning-Gaese, K. 2007. Effects of climate and land-use change on species abundance in a central European bird community. Conservation Biology 21: 495-503.

What was done
Using data from the semi-quantitative Breeding Bird Atlas of Lake Constance, which borders Germany, Switzerland and Austria, the authors analyzed the impact of land-use and climate changes on the region's abundance of Central European birds between the periods 1980-1981 and 1990-1992 and between 1990-1992 and 2000-2002.

What was learned
Lemoine et al. report that "the total number of [bird] species in the Lake Constance region increased from 141 species in 1980 to 146 species in 1990 and to 154 species in 2000," while "winter temperatures increased by 2.71C and spring temperatures increased by 2.12C over the 23 years from the first to the last census," noting additionally that "the impact of climate change on bird populations increased in importance between 1990 and 2000 and is now more significant than any other tested factor [our italics]."

What it means
In the words of the four researchers, "increases in temperature appear to have allowed increases in abundance of species whose range centers were located in southern Europe and that may have been limited by low winter or spring temperature." Hence, like so many other studies (see Birds in our Subject Index), their work demonstrates that rising temperatures generally allow birds to extend, both poleward in latitude and upward in elevation, the low-temperature boundaries of their ranges, while largely maintaining the positions of the high-temperature boundaries of their ranges. As a result, there is a greater overlapping of species ranges as temperatures rise, with the result that local and regional species richness also increases, which observational fact runs totally counter to the climate-alarmist claim that global warming will lead to decreases in species richness. See also, in this regard, our major report The Specter of Species Extinction:Will Global Warming Decimate Earth's Biosphere?.

Reviewed 15 October 2008