Reducing human activity promotes environmental restoration in arid and semi-arid regions: A case study in Northwest China

Chuanhua Li; Yutao Wang; Xiaodong Wu; Hongjuan Cao; Wangping Li; Tonghua Wu

doi:10.1016/j.scitotenv.2020.144525

Reducing human activity promotes environmental restoration in arid and semi-arid regions: A case study in Northwest China

Sci Total Environ. 2021 May 10:768:144525. doi: 10.1016/j.scitotenv.2020.144525. Epub 2021 Jan 7.

Authors

Chuanhua Li¹, Yutao Wang², Xiaodong Wu³, Hongjuan Cao², Wangping Li⁴, Tonghua Wu⁵

Affiliations

¹ College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China; Cryosphere Research Station on the Qinghai-Tibet Plateau, State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730070, China.
² College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China.
³ Cryosphere Research Station on the Qinghai-Tibet Plateau, State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730070, China; University of Chinese Academy Sciences, Beijing 100049, China. Electronic address: wuxd@lzb.ac.cn.
⁴ School of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
⁵ Cryosphere Research Station on the Qinghai-Tibet Plateau, State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730070, China; University of Chinese Academy Sciences, Beijing 100049, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), 511458, China.

PMID: 33453528
DOI: 10.1016/j.scitotenv.2020.144525

Abstract

Human activities have adversely impacted grassland net primary productivity (NPP) across the world, and quantitative estimations of the anthropogenic impacts on NPP (HNPP) can be helpful to improve environmental protection and climate adaptation measures. However, disentangling the effects of climate variability and human activities on NPP is problematic and requires the calculation of potential net primary productivity (PNPP). In this study, we assessed the anthropogenic impacts on NPP in the Shiyang River basin-a typical arid and semi-arid region. We used the seasonal changes in NPP to identify the grids that were not affected by human activity and then proposed a method to calculate PNPP based on the leaf area index (LAI). We estimated the actual net primary productivity (ANPP) using the Carnegie-Ames-Stanford Approach (CASA) model, and the HNPP was then calculated as the difference between ANPP and PNPP. Our results showed that this method for PNPP calculation was reliable. From 2001 to 2016, the positive (90.85 gC·m^-2·a^-1) and negative effects (-130.21 gC·m^-2·a^-1) of human activities on NPP accounted for 32.68% and 46.84% of the ANPP, respectively, and the overall average HNPP was -39.36 g C·m²·a^-1. The implementation of ecological and environmental protection projects gradually mitigated the negative effects of human activity on NPP at a rate of 4.55 gC·m^-2·a^-1; however, negative HNPP values still occupied 55.39% of the entire region in 2016. In contrast with the prevailing views that climate change is the main factor accounting for vegetation recovery in arid and semi-arid regions, our results suggest that reducing human activities can significantly promote environmental restoration. The findings of this study suggest that policy makers and stakeholders can restore grassland ecosystems and promote environmental protection by reducing anthropogenic activities in arid and semi-arid regions.

Keywords: CASA model; Ecological environment; Grassland; Human activities; Net primary productivity.

MeSH terms

China
Climate Change
Ecosystem*
Environmental Restoration and Remediation*
Human Activities
Humans