Ecological water demand of regional vegetation: The example of the 2010 severe drought in Southwest China

To determine the cause of the severe drought that hit five provinces (autonomous regions, municipalities) of Southwest China in 2010, the ecological water demand (EWD) of regional vegetation was explored. The key scientific question was whether the plantation of Eucalyptus and Hevea trees in this area could have led to the breaking of the regional EWD balance, thereby causing a regional drought. Therefore, major research progress and trends related to EWD of vegetation, such as characterization of vegetation water consumption from transpiration and eco-hydrological effects, were explored. Theories, methods, and practices regarding EWD of vegetation, and the correlation between regional vegetation types and droughts were evaluated. Finally, suggestions were made for specific scientific research on temporal and spatial evolution of typical artificial vegetation in Southwest China and on the relationship between EWD from regional vegetation and droughts. Thus, future research should include the following three aspects: (i) historical evolution and distribution pattern of regional artificial vegetation; (ii) water consumption from transpiration, water saving for drought prevention, and water and soil conservation of regional artificial vegetation; and (iii) the relationship between EWD of regional artificial vegetation and regional droughts. The proposed research focus is expected to provide a scientific basis for identifying the causes of regional droughts and the reasonable allocation of water resources. In addition, it will be of great importance in guiding restoration and reconstruction of regional artificial vegetation.