Temporal Variability in Aboveground Plant Biomass Decreases as Spatial Variability Increases

Authors

Devan Allen McGranahan, North Dakota State UniversityFollow
Torre J. Hovick, North Dakota State UniversityFollow
R. Dwayne Elmore, Oklahoma State UniversityFollow
David M. Engle, Oklahoma State UniversityFollow
Samuel D. Fuhlendorf, Oklahoma State UniversityFollow
Stephen L. Winter, Oklahoma State UniversityFollow
James R. Miller, University of IllinoisFollow
Diane M. Debinski, Iowa State UniversityFollow

Document Type

Article

Date of this Version

2016

Citation

Ecology (2016) 97(3): 555–560.

Comments

Copyright © 2016, Ecological Society of America. Used by permission.

Abstract

Ecological theory predicts that diversity decreases variability in ecosystem function. We predict that, at the landscape scale, spatial variability created by a mosaic of contrasting patches that differ in time since disturbance will decrease temporal variability in aboveground plant biomass. Using data from a multi-year study of seven grazed tallgrass prairie landscapes, each experimentally managed for one to eight patches, we show that increased spatial variability driven by spatially patchy fire and herbivory reduces temporal variability in aboveground plant biomass. This pattern is associated with statistical evidence for the portfolio effect and a positive relationship between temporal variability and functional group synchrony as predicted by metacommunity variability theory. As disturbance from fire and grazing interact to create a shifting mosaic of spatially heterogeneous patches within a landscape, temporal variability in aboveground plant biomass can be dampened. These results suggest that spatially heterogeneous disturbance regimes contribute to a portfolio of ecosystem functions provided by biodiversity, including wildlife habitat, fuel, and forage. We discuss how spatial patterns of disturbance drive variability within and among patches.