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United States Department of Agriculture

Agricultural Research Service

Research Project: Ecohydrological Processes, Scale, Climate Variability, and Watershed Management

Location: Southwest Watershed Research

Title: Extreme precipitation patterns reduced terrestrial ecosystem production across biomass

Authors
item Zhang, Y. -
item Moran, Mary
item Nearing, Mark
item Ponce Campos, G.E. -
item Huete, A. -
item Buda, Anthony
item Bosch, David
item Gunter, Stacey
item Kitchen, S.G. -
item Mcnab, W.H. -
item Morgan, Jack
item Mcclaran, M. -
item Sutherland Montoya, D. -
item Peters, Debra
item Starks, Patrick

Submitted to: Journal of Geophysical Research-Biogeosciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 30, 2012
Publication Date: March 1, 2013
Citation: Zhang, Y., Moran, M.S., Nearing, M.A., Ponce Campos, G., Huete, A., Buda, A.R., Bosch, D.D., Gunter, S.A., Kitchen, S., Mcnab, W., Morgan, J.A., Mcclaran, M., Sutherland Montoya, D., Peters, D.C., Starks, P.J. 2013. Extreme precipitation patterns reduced terrestrial ecosystem production across biomass. Journal of Geophysical Research-Biogeosciences. 118:148–157.

Interpretive Summary: Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more intense rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of novel climatic conditions on aboveground net primary production (ANPP) by combining a greenness index from satellite measurements and climatic records during 2000 to 2009 from 11 long-term experimental sites in multiple biomes and climates. Results showed that extreme precipitation patterns decreased the sensitivity of ANPP to total annual precipitation (PT), at the regional and decadal scales, leading to a mean 20% decrease in rain-use efficiency across biomes. Relative decreases in ANPP were greatest for arid grassland (16%) and Mediterranean forest (20%), and less for mesic grassland and temperate forest (3%). The co-occurrence of more heavy rainfall events and longer dry intervals caused greater water stress that resulted in reduced vegetation production. A new generalized model was developed to improve predictions of the ANPP response to changes in extreme precipitation patterns by using a function of both PT and an index of precipitation extremes. These findings suggest that extreme precipitation patterns have more substantial and complex effects on vegetation production across biomes, and are as important as total annual precipitation in understanding vegetation processes. With predictions of more extreme weather events, forecasts of ecosystem production should consider these non-linear responses to altered precipitation patterns associated with climate change.

Technical Abstract: Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more intense rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of novel climatic conditions on aboveground net primary production (ANPP) by combining a greenness index from satellite measurements and climatic records during 2000 to 2009 from 11 long-term experimental sites in multiple biomes and climates. Results showed that extreme precipitation patterns decreased the sensitivity of ANPP to total annual precipitation (PT), at the regional and decadal scales, leading to a mean 20% decrease in rain-use efficiency across biomes. Relative decreases in ANPP were greatest for arid grassland (16%) and Mediterranean forest (20%), and less for mesic grassland and temperate forest (3%). The co-occurrence of more heavy rainfall events and longer dry intervals caused greater water stress that resulted in reduced vegetation production. A new generalized model was developed to improve predictions of the ANPP response to changes in extreme precipitation patterns by using a function of both PT and an index of precipitation extremes. These findings suggest that extreme precipitation patterns have more substantial and complex effects on vegetation production across biomes, and are as important as total annual precipitation in understanding vegetation processes. With predictions of more extreme weather events, forecasts of ecosystem production should consider these non-linear responses to altered precipitation patterns associated with climate change.

Last Modified: 9/21/2014
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