Grassland vegetation changes and nocturnal global warming
Global minimum temperatures (TMIN) 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 TMIN and several vegetation variables. This ecosystem is potentially sensitive to increases in TMIN. Most notably, increased spring TMIN 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.
Alward
RD
R. D. Alward, Graduate Degree Program in Ecology and Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA. J. K. Detling, Department of Biology and Natural Resource Ecology Laboratory, Colorado State Un.
Detling
JK
Milchunas
DG