Carbon isoscapes of rodent diets in the Great Plains USA deviate from regional gradients in C4 grass abundance due to a preference for C3 plant resources

摘要: Abstract Diet is an ecological attribute that species may adjust to cope with changing environments and indicate how a population responds changes in resource availability. In the Great Plains, plants utilizing C4 photosynthetic pathway increase abundance future because of their high tolerance for warm dry environments, which are projected increase. How increased will influence grassland food webs remains unknown. Here, we evaluate rodent diets vary relative plant biomass at regional scale southern Plains U.S. We measured δ13C values hair from 534 individuals 14 species. Resulting isoscapes were statistically compared three proxies local grasses across region. Overall, most dominated by C3-derived resources few relying on resources. Ordinary least squares linear regressions explain very little variance entire community, however isoscape does broadly correspond soil organic matter. The difference between median granivores folivores significantly highly correlated SOM values. Results this study can be used as baseline characterizing dietary shifts response environmental change both geological past future, they identify categories sensitive grasses.