Forty Years of Increasing Precipitation is Correlated with Loss of Forbs in a Tallgrass Prairie

Abstract

The effects of climate change on plant communities are already observable in many regions. In the tallgrass region of the Northern Great Plains, plant community composition may have shifted in response to increases in both annual precipitation and temperature. We compared community composition of a tallgrass prairie among three sampling periods (1978–1979, 1998, and 2014), spanning more than three decades, in order to better understand (1) temporal shifts in plant cover and (2) which environmental variables were correlated with these changes. Basal cover of Poa pratensis increased and basal cover of forbs declined over time. The shift from a forb-rich to grass-dominated prairie was positively correlated with higher levels of precipitation and soil moisture. Our study suggests that increased precipitation due to climate change has already altered plant community composition in the Great Plains.