J. M. Cotton, T.E. Cerling, K.A. Hoppe, T.M. Mosier, C.J. Still. 2016. Climate, CO2, and the history of North American grasses since the Last Glacial Maximum. Science Advances, Vol. 2, no. 3, e1501346. DOI: 10.1126/sciadv.1501346

Type: 
Literature
Publication: 
J. M. Cotton, T.E. Cerling, K.A. Hoppe, T.M. Mosier, C.J. Still. 2016. Climate, CO2, and the history of North American grasses since the Last Glacial Maximum. Science Advances, Vol. 2, no. 3, e1501346. DOI: 10.1126/sciadv.1501346
Year Published: 
2016
Description: 

A new study published in Science Advances evaluated the climatic factors that influenced the compositional change in North American Grasses from the Last Glacial Maximum to present. Specifically, the authors examined the massive expansion of C4 grasses during the late Neogene era. The study first determined the "isotopic landscape" of C3/C4 grasses during the Last Glacial Maximum, mid-Holocene, and present using stable isotope composition found in mammoth and bison tissue. The study then used three statistical tests (classification and regression trees) to determine the climatic variables most influential for C4 grass expansion, which they found to be precipitation and temperature during growing season. The authors then compared their "isotopic landscapes" to climate data from the Last Glacial Maximum to the present and discovered that C4 grass expansion continued through the Great Plains during a time of increased atmospheric CO2 concentrations. The authors were able to conclude that precipitation, rather than temperature, during growing season was a critical factor in C4 grass expansion.

Category: 
Historical Climate Change, Climate Modeling