A paper in the Feb. 10 issue of the journal Nature titled Abrupt Rise in Atmospheric CO2 Overestimates Community Response in a Model Plant-Soil System, takes a closer look at this aspect of climate modeling. University of California, Riverside Professor of Plant Pathology and Biology, Michael Allen is part of the research team that wrote the paper with John N. Klironomos, Shokouh Makvandi-Nejad, Benjamin E. Wolfe, and Jeff R. Powell of the Department of Botany, University of Guelph, Ontario, Canada; and Matthias C. Rilling and Jeff Piotrowski of the Division of Biological Sciences, University of Montana. The work was supported by the Canadian Government, the U. S. Department of Energy, and the U. S. National Science Foundation.
The team observed the response of a mycorrhizal fungal community to CO2 concentrations over a span of six years, which included 21 generations. The fungi, which live around the root systems of plants, are considered a beneficial partner to plants helping them cope with natural stresses, such as low soil fertility, drought and temperature extremes.
The fungi were exposed to either an abrupt or gradual increase in this atmospheric gas. The group exposed to a slow rise in CO2 concentration showed less of a decline in the number of species per sample a standard ecological measure of biodiversity of the fungi than did the group exposed to the abrupt change, but the difference was not significant.
The findings suggest that previous work has overestimated the magnitude of community and ecosystem responses to carbon dioxide changes, the researchers say.