Ecosystems have increasingly been subject to the stress of heavy drought under global warming. To quantify its impacts, a drought index that can sensitively depict the reaction of vegetation to drought evolution is necessary at a biological time scale. The difference between actual and potential evapotranspiration, technically termed a standardized evapotranspiration deficit drought index (SEDI), can more sensitively capture the biological changes of ecosystems in response to the dynamics of drought intensity, compared with indices based on precipitation and temperature. Prof. Zhuguo MA, Director of the Key Laboratory of Regional Climate-Environment for Temperate East Asia at the Institute of Atmospheric Physics, Chinese Academy of Sciences, and his team, have published this finding in Advances of Atmospheric Sciences.
"In terms of the role played by evapotranspiration deficit in connecting climate and ecosystem processes, SEDI has the potential of highlighting drought impacts on ecological processes," says Associate Prof. LI Mingxing, corresponding author of the study.
"Actually, several studies have used evapotranspiration deficit in drought studies. However, their potential in delineating vegetation responses to climatic fluctuations and heavy droughts has not yet been specifically assessed, in contrast to the evaluation of their detection ability," he states. "The objective of this study was, based on the standardized evapotranspiration deficit, to define a drought index and assess its effectiveness in highlighting vegetation responses to drought evolution."
Read more at Institute of Atmospheric Physics, Chinese Academy of Sciences
Image: Drought in Wuwei, Gansu Province, located in northwest China. Photo taken in July 2015. (Image by ZHANG Jingpeng)