PRS Publications

Effects of increased temperature on plant communities depend on landscape location and precipitation.

Cowles, J., Boldgiv, B., Liancourt, P., Petraitis, P. S., & Casper, B. B.. 2018.

Abstract

Global climate change is affecting and will continue to affect ecosystems worldwide. Specifically, temperature and precipitation are both expected to shift globally, and their separate and interactive effects will likely affect ecosystems differentially de- pending on current temperature, precipitation regimes, and other biotic and environ- mental factors. It is not currently understood how the effects of increasing temperature on plant communities may depend on either precipitation or where communities lie on soil moisture gradients. Such knowledge would play a crucial role in increasing our predictive ability for future effects of climate change in different systems. To this end, we conducted a multi- factor global change experiment at two locations, differing in temperature, moisture, aspect, and plant community composi- tion, on the same slope in the northern Mongolian steppe. The natural differences in temperature and moisture between locations served as a point of comparison for the experimental manipulations of temperature and precipitation. We conducted two separate experiments, one examining the effect of climate manipulation via open- top chambers (OTCs) across the two different slope locations, the other a factorial OTC by watering experiment at one of the two locations. By combining these experi- ments, we were able to assess how OTCs impact plant productivity and diversity across a natural and manipulated range of soil moisture. We found that warming ef- fects were context dependent, with the greatest negative impacts of warming on diversity in the warmer, drier upper slope location and in the unwatered plots. Our study is an important step in understanding how global change will affect ecosys- tems across multiple scales and locations.

Key Words

biodiversity, context dependency, global change experiment, open-top chambers, precipitation, primary productivity