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The Drought Tolerance of Grasslands
Craine, J.M., Ocheltree, T.W., Nippert, J.B., Towne, E.G., Skibbe, A.M., Kembel, S.W. and Fargione, J.E. 2013. Global diversity of drought tolerance and grassland climate-change resilience. Nature Climate Change 3: 63-67.

Climate alarmists contend that many regions of the world will experience more frequent, more severe and longer-lasting droughts as the earth continues to warm in response to the ongoing rise in the atmosphere's CO2 concentration; and as a result of this ominous climate-model-projected phenomenon, they express great concern about the possibility that the planet's grasslands could be severely impacted.

What was done
"To better understand drought tolerance in grasslands," in the words of Craine et al., they "assessed physiological drought tolerance and a number of other leaf functional traits for [an amazing] 426 grass species."

What was learned
The seven scientists report that physiological drought tolerance, which varied tenfold among the 426 grass species, "is well distributed both climatically and phylogenetically," suggesting that "most native grasslands are likely to contain a high diversity of drought tolerance." Thus, as they continue, "local species may help maintain ecosystem functioning in response to changing drought regimes without requiring long-distance migrations of grass species." In addition, they found that the "physiologically drought-tolerant species had higher rates of water and carbon dioxide exchange than intolerant species, indicating that severe droughts may generate legacies for ecosystem functioning."

What it means
In summing up the significance of their findings, Craine et al. write that "diverse grasslands throughout the globe have the potential to be resilient to drought in the face of climate change through the local expansion of drought-tolerant species," citing as a real-world example the fact that "plant productivity in Kansas and Nebraska grasslands was maintained during drought in the 1930s, not by the immigration of drought-tolerant species, but by local expansion of these species after less-tolerant species perished," citing Weaver et al. (1935) and Weaver (1968).

Weaver, J.E. 1968. Prairie Plants and Their Environment: A Fifty-Year Study in the Midwest. University of Nebraska Press, Lincoln, Nebraska, USA.

Weaver, J.E., Stoddart, L.A. and Noll, W. 1935. Response of the prairie to the Great Drought of 1934. Ecology 16: 612-629.

Reviewed 29 May 2013