Convergence of Dynamic Vegetation Net Productivity Responses to Precipitation Variability from 10 Years of MODIS EVI

Authors: PONCE, G. - University Of Arizona; Moran, Mary; HUETE, A. - University Of Technology Sydney; BRESLOFF, C. - University Of Arizona; HUXMAN, T. - University Of Arizona; Bosch, David; BRADFORD, J. - Us Forest Service (FS); Buda, Anthony; Gunter, Stacey; MCNAB, H. - Us Forest Service (FS); MCCLARAN, M. - University Of Arizona; Peters, Debra; Sadler, Edward; Seyfried, Mark; Starks, Patrick; SUTHERLAND MONTOYA, D. - Us Forest Service (FS); HEARTSILL, T. - Us Forest Service (FS)

Submitted to: International Symposium on Remote Sensing Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2011
Publication Date: 4/10/2011
Citation: Ponce, G., Moran, M.S., Huete, A., Bresloff, C., Huxman, T., Bosch, D.D., Bradford, J., Buda, A.R., Gunter, S.A., Mcnab, H., Mcclaran, M., Peters, D.C., Sadler, E.J., Seyfried, M.S., Starks, P.J., Sutherland Montoya, D., Heartsill, T. 2011. Convergence of Dynamic Vegetation Net Productivity Responses to Precipitation Variability from 10 Years of MODIS EVI. ISRSE 2011, 34th International Symposium on Remote Sensing of Environment, Sydney Convention and Exhibition Centre, 10-15 April 2011.

Interpretive Summary: There is great scientific and public interest in the impact that climate change will have on vegetation across the United States. Due to the great diversity of vegetation at the continental scale, scientists have turned to satellites for information about how changes in precipitation will influence plant growth. In this study, decades of measurements of climate and vegetation at 13 USDA experimental sites were synthesized to generalize the potential impact of climate change on vegetation ranging from desert grassland in Arizona to tropical forest in Puerto Rico. First, results showed that satellite measurements offer a viable surrogate for time- and labor-intensive field measurements of plant growth. Second, it appears that the lower precipitation predicted with climate change will cause all biomes (grassland to forest) to utilize water more efficiently. This study offers a new paradigm for climate change research based on interpretation of satellite measurements over large regions. The results of this study will influence the management of our national renewable resources with a better understanding of how vegetation will respond to predicted climate change.

Technical Abstract: According to Global Climate Models (GCMs) the occurrence of extreme events of precipitation will be more frequent in the future. Therefore, important challenges arise regarding climate variability, which are mainly related to the understanding of ecosystem responses to changes in precipitation patterns. Previous studies have found that Above-ground Net Primary Productivity (ANPP) was positively related to increases in annual precipitation and this relation may converge across biomes during dry years. One challenge in studying this ecosystem response at the continental scale is the lack of ANPP field measurements over extended areas. In this study, the MODIS EVI was utilized as a surrogate for ANPP and combined with precipitation datasets from twelve different experimental sites across the United States over a 10-year period. Results from this analysis confirmed that integrated-EVI for different biomes converged toward common precipitation use efficiency during water-limited periods and may be a viable surrogate for ANPP measurements for further ecological research.