title: Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China.
abstract: Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values' responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky desertification areas. Understanding the vegetation ecological water consumption response to the vegetation coverage changes is essential for the vegetation restoration and water stresses mitigation in rocky desertification areas.
authors: Jianshui Karst Ecosystem of the National Field Research Station, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China.
authors: Long
authors: L
authors: Wan
authors: Jianshui Karst Ecosystem of the National Field Research Station, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China.|The College of Forestry, Beijing Forestry University, Beijing, China.
authors: Jing
authors: J
authors: Tong
authors: Jianshui Karst Ecosystem of the National Field Research Station, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China.
authors: Jinxing
authors: J
authors: Zhou
authors: Jianshui Karst Ecosystem of the National Field Research Station, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China.
authors: Hongyan
authors: H
authors: Guo
authors: Institute of Desertification Studies, Chinese Academy of Forestry, Beijing, China.
authors: Ming
authors: M
authors: Cui
authors: Institute of Desertification Studies, Chinese Academy of Forestry, Beijing, China.
authors: Yuguo
authors: Y
authors: Liu
authors: Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.|Graduate University of Chinese Academy of Sciences, Beijing, China.
authors: Like
authors: L
authors: Ning
authors: Institute of Desertification Studies, Chinese Academy of Forestry, Beijing, China.
authors: Fukai
authors: F
authors: Tang
mesh_terms: D002681:China; D003247:Conservation of Natural Resources; D004463:Ecology; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring; D005843:Geography; D010944:Plants; D011891:Rain; D062206:Spatial Analysis; D014867:Water
chemical_list: D014867:Water