Drought Offset Ecological Restoration Program-Induced Increase in Vegetation Activity in the Beijing-Tianjin Sand Source Region, China

Abstract

To improve the ecological conditions, the Chinese government adopted six large-scale ecological restoration programs including 'Three-North Shelterbelt Project', "Grain for Green Project" and "Beijing-Tianjin Sand Source Control Project". Meanwhile, these ecologically vulnerable areas have experienced frequent droughts. However, little attention has been paid to the impact of drought on the effectiveness of these programs. Taking Beijing-Tianjin Sand Source Region (BTSSR) as study area, we investigated the role of droughts and ecological restoration program on trends of vegetation activities and to address the question of a possible "drought signal" in assessing effectiveness of ecological restoration program. The results demonstrate the following: (1) Vegetation activity increased in the BTSSR during 2000-2010, with 58.44% of the study area showing an increased NDVI, of which 11.80% had a significant increase at 0.95 confidential level. The decreasing NDVI trends were mainly concentrated in a southwest-to-northeast strip in the study area. (2) Drought was the main driving force for a decreasing trend of vegetation activity in the southwest-to-northeast regions of the BTSSR at the regional and spatial scales. Summer droughts in 2007 and 2009 contributed to the decreasing trend in NDVI. The severe and extreme droughts in summer reduced the NDVI by approximately 13.06% and 23.55%, respectively. (3) The residual analysis result showed that human activities, particularly the ecological restoration programs, have a positive impact on vegetation change. Hence, the decreasing trends in the southwest-to-northeast regions of the BTSSR cannot be explained by the improper ecological restoration program and is partly explained by droughts, especially summer droughts. Therefore, drought offset the ecological restoration program-induced increase in vegetation activity in the BTSSR.

Rural Household Preferences for Active Participation in “Payment for Ecosystem Service” Programs: A Case in the Miyun Reservoir Catchment, China

“…An example is the Sand Control Program in the Beijing-Tianjin Sand Source Regions [48–49]. More importantly, participants are not obliged to contract their own land with the programs.…”

Multiple afforestation programs accelerate the greenness in the ‘Three North’ region of China from 1982 to 2013

“…The significant increase of greening trend in NNS after 2000 confirmed the investment. However, due to the increased drought frequency and urbanization, the greening trend may have been partially offset, especially in the Beijing Tianjin urban area (Shan et al, 2015;Wu et al, 2014). The MXS benefited the least from the three programs and therefore maintained its original greening speed.…”

Response of vegetation activity dynamic to climatic change and ecological restoration programs in Inner Mongolia from 2000 to 2012

“…Due to the robust relationship between normalized difference vegetation index (NDVI) and vegetation production, NDVI has commonly been used as a proxy of vegetation activity (Boschetti et al, 2013;Jobbágy et al, 2002). The MODIS NDVI products with multiple spatial resolutions (250 m, 500 m and 1 km) and multiple temporal resolutions (8 days, 16 days and 1 month) have always been used for vegetation dynamic research (Fensholt and Proud, 2012;Wu et al, 2013Wu et al, , 2014. In this research, vegetation activity refers to green vegetation cover as determined by MODIS NDVI.…”