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Effects of Elevated CO2 and O3 on Prairie Voles' Feeding & Growth
Reference
Habeck, C.W. and Lindroth, R.L. 2013. Influence of global atmospheric change on the feeding behavior and growth performance of a mammalian herbivore, Microtus ochrogaster. PLOS ONE 8: 10.1371/journal.pone.0072717.

Background
The authors write that "a general reduction in plant quality due to GAC [global atmospheric changes] is expected to have significant impacts on herbivore populations by reducing growth rate, fecundity or survival," but they say that to their knowledge, "there are no published accounts on the growth response of herbivorous mammals to these GAC-mediated changes in plant quality."

What was done
Hoping to provide such an account, Habeck and Lindroth "investigated the impacts of elevated carbon dioxide (CO2) and ozone (O3) on the phytochemistry of two forbs, Solidago canadensis and Taraxacum officinale," as well as "the subsequent feeding behavior and growth performance of weanling prairie voles (Microtus ochrogaster) feeding on those plants," which they obtained from the understory of the Aspen FACE facility near Rhinelander, Wisconsin, USA, where they had been grown in either ambient air, elevated CO2 air (560 ppm) or elevated O3 air (ambient x 1.5).

What was learned
First of all, the two researchers report that "elevated CO2 and O3 altered the foliar chemistry of both forbs." More specifically, they say that "elevated CO2 increased the fiber fractions of both plant species, whereas O3 fumigation elicited strong responses among many phytochemical components, most notably increasing the carbon-to-nitrogen ratio by 40% and decreasing N by 26%." As a result, they indicate that "male voles were unaffected by the fumigation treatments, whereas female voles grew 36% less than controls when fed O3-grown plants."

What it means
Whereas atmospheric CO2 enrichment had no discernible negative impacts on the growth and development of young male and female voles, O3 "enrichment" of the air was clearly detrimental to the growth of females. And that is but one of a host of reasons why ozone is called a pollutant and CO2 is not ... except by the U.S. Environmental Protection Agency, which has really got things all screwed up when it comes to what should be called the "elixir of life."

Reviewed 11 December 2013