Impacts of climate change and human activities on grassland vegetation variation in the Chinese Loess Plateau

Kai Zheng; Jian-Zhou Wei; Jiu-Ying Pei; Hua Cheng; Xu-Long Zhang; Fu-Qiang Huang; Feng-Min Li; Jian-Sheng Ye

doi:10.1016/j.scitotenv.2019.01.022

Impacts of climate change and human activities on grassland vegetation variation in the Chinese Loess Plateau

Sci Total Environ. 2019 Apr 10:660:236-244. doi: 10.1016/j.scitotenv.2019.01.022. Epub 2019 Jan 4.

Authors

Kai Zheng¹, Jian-Zhou Wei¹, Jiu-Ying Pei¹, Hua Cheng¹, Xu-Long Zhang¹, Fu-Qiang Huang¹, Feng-Min Li², Jian-Sheng Ye³

Affiliations

¹ State Key Laboratory of Grassland Agro-ecosystems, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, No. 222, South Tianshui Road, Lanzhou 730000, China.
² State Key Laboratory of Grassland Agro-ecosystems, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, No. 222, South Tianshui Road, Lanzhou 730000, China. Electronic address: fmli@lzu.edu.cn.
³ State Key Laboratory of Grassland Agro-ecosystems, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, No. 222, South Tianshui Road, Lanzhou 730000, China. Electronic address: yejsh@lzu.edu.cn.

PMID: 30640092
DOI: 10.1016/j.scitotenv.2019.01.022

Abstract

China initiated the "Grain for Green Project" in 1999 to mitigate soil erosion. The vegetation cover of the Chinese Loess Plateau, one of the most erosive regions in the world, has been greatly increased. However, studies on quantitatively investigating the climate change and human activities on vegetation coverage change were rare. In this study, spatio-temporal changes in vegetation coverage were investigated using MODIS normalized difference vegetation index (NDVI) data over 2000-2016. And a new method was introduced using Net Primary Productivity (NPP) model and relationship between NPP and NDVI to quantitatively and spatially distinguish the NDVI affected by climate change and human activities. Results showed that mean NDVI value over 2009-2016 were 14.46% greater than that over 2000-2007. In order to quantify the contribution of climate change and human activities to vegetation change, an NPP model suitable for the grassland of the Chinese Loess Plateau was identified using biomass observations from field survey and literature. The NDVI affected by climate change (NDVI_climate) was estimated by the NPP model and the relationship between NPP and NDVI. And the NDVI affected by human activities (NDVI_human) was calculated by actual NDVI minus NDVI_climate. Comparison of the two stages showed that human activities and climate change contributed 42.35% and 57.65% respectively to the ΔNDVI on grassland in the Loess Plateau. After analysis of numerous NDVI_human related factors, the slopes restored by the "Grain for Green Project" was considered the main influence factor of human activities.

Keywords: Climate change; Grain for Green Project; Human activities; Loess Plateau; Vegetation change.

MeSH terms

Biomass*
China
Climate Change*
Environmental Monitoring / methods*
Grassland*
Human Activities*
Models, Theoretical