Contributions of ecological programs to vegetation restoration in arid and semiarid China

• Published in: Environmental research letters Vol. 15; no. 11; pp. 114046 - 114056
• Main Authors: Cai, Diwen, Ge, Quansheng, Wang, Xunming, Liu, Baoli, Goudie, Andrew S, Hu, Shi
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.2020
• Subjects: arid and semiarid China; Arid regions; Carbon dioxide; Carbon dioxide concentration; Climate change; Desertification; Dust storms; Ecological effects; ecological program; Environmental restoration; Grasslands; Restoration; Solar radiation; Storms; Vegetation; Vegetation effects; vegetation restoration; Wind speed; China
• ISSN: 1748-9326; 1748-9326
• DOI: 10.1088/1748-9326/abbde9

Over the past four decades, large-scale ecological programs, including the 'Great Green Wall Program' (1978-present), 'Grain for Green Program' (1999-present), 'Grassland Ecological Protection Program' (2000-present), and 'Beijing-Tianjin Sandstorm Source Control Project' (2002-present), were launched to restore vegetation, to combat desertification, and to control dust storms in arid and semiarid China. The gross investments of these programs have exceeded 1700 billion RMB (∼260 billion USD, accounting for ∼1% GDP in the region) by now, however, the effects of these programs on vegetation restoration have not been settled. In this study, the vegetation indices, land-uses, and climatic factors were used to estimate the contribution of the above programs on vegetation restoration. The results showed that consistent vegetation restoration has occurred in about 45.3% of the vegetated areas in arid and semiarid China from 1982 to 2000, and the percentage decreased to 33.6% after 2000 despite more ecological programs have been launched. Changes in climatic factors (precipitation, temperature, solar radiation, and wind speed) and elevated atmospheric CO2 concentration contributed more than 50% and 70% to vegetation restoration in periods of 1982-2000 and 2001-2015, respectively, however, the contribution rate of ecological programs kept stable at about 20%. Climate changes in the past forty years played a dominant role, although the ecological programs showed a noticeable effect on vegetation restoration. Further investment in ecological restoration practices might need to be critically evaluated on the cost-effectiveness.