Effects of increased temperature on plant communities depend on landscape location and precipitation.
Cowles, J., Boldgiv, B., Liancourt, P., Petraitis, P. S. and 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
