Grassland Vegetation Changes and Nocturnal Global Warming

Authors

Richard D. Alward, University of Nebraska–Lincoln
James K. Detling, Colorado State University - Fort Collins
Daniel G. Milchunas, Colorado State University - Fort Collins

Date of this Version

1999

Comments

Published in Science 283, no. 5399 (January 8, 1999), pp. 229-231; doi: 10.1126/science.283.5399.229 Copyright © 1999 American Association for the Advancement of Science. Used by permission.

Abstract

Global minimum temperatures (T_MIN) are increasing faster than maximum temperatures, but the ecological consequences of this are largely unexplored. Long-term data sets from the shortgrass steppe were used to identify correlations between T_MIN and several vegetation variables. This ecosystem is potentially sensitive to increases in T_MIN. Most notably, increased spring T_MIN was correlated with decreased net primary production by the dominant C₄ grass (Bouteloua gracilis) and with increased abundance and production by exotic and native C₃ forbs. Reductions in B. gracilis may make this system more vulnerable to invasion by exotic species and less tolerant of drought and grazing.