Esposito, Rhea听1听;听Horn, Shannon听2听;听McKnight, Diane听3听;听Cox, Michael听4听;Grant, M.听5听;听Spaulding, Sarah听6听;听Doran, Peter听7听;听Stanish, Lee听8
8听Presenting Author
1听滨狈厂罢础础搁
2听
3听滨狈厂罢础础搁
4听
5听
6听滨狈厂罢础础搁, USGS
7听University of Illinois at Chicago
8听滨狈厂罢础础搁
To understand biotic responses to an Antarctic cooling trend, we analyzed diatom samples from glacial meltwater streams in the McMurdo Dry Valleys, the largest ice-free area in Antarctica. Diatoms are abundant in these streams, and 24 of 40 species have only been found in the Antarctic. The percentage of these Antarctic diatom species increased with decreasing annual stream flow and increasing harshness of the stream habitat. The species diversity of assemblages reached a maximum when the Antarctic species accounted for 40 鈥�60% of relative diatom abundance. Decreased solar radiation and air-temperatures reduce annual stream flow, raising the dominance of these Antarctic species to levels above 60%. Thus, cooling favors the Antarctic species, and lowers diatom species diversity in this region.
Doran, P. T., et al. 2002. Antarctic climate cooling and terrestrial ecosystem response: Nature, v. 415, p. 517鈥�520.