Human-induced grassland degradation/restoration in the central Tibetan Plateau: The effects of ecological protection and restoration projects

Abstract

A B S T R A C TEcological projects are an important and vital method to help ecosystem adaptation and restoration in response to the environment change and human interference. The accurate and objective assessment of ecological projects will assist ecosystem management and adaption. This study took the central Tibetan Plateau as the study area, where a series of ecological projects has been implemented since 2005 to prevent grassland degradation by protecting and restoring the grasslands. Our aim is to explore where and to what extent the ecological projects influenced the grassland variation, using SPOT NDVI-based residual trend as an indicator. The results indicated that before the projects (between 1998 and 2004), human-induced degradation characterized the grassland. However, a general grassland restoration was detected after the projects from 2005 to 2012. Moreover, over 60% of project plots had positive trends in the NDVI residuals. From the spatial patterns, project-induced restoration was detected in the western and northern regions, such as Maduo, Dongde and Xinghai counties. For the eastern regions, the human-induced degradation has been generally mitigated and yet not reversed after the projects. Our results indicated that ecological protection and restoration projects in the central Tibetan Plateau have mitigated the grassland degradation and even reversed the degradation in some areas, and also suggested that the NDVI-based residual trend is a useful indicator for assessing the effectiveness of the ecological projects in alpine regions.

Permafrost collapse shifts alpine tundra to a carbon source but reduces N2O and CH4 release on the northern Qinghai‐Tibetan Plateau

“…For example, we observed no vegetation recolonization of exposed patches at our study site over 10 years, and at a similar thermo-erosion feature on the QTP, there was no growth after 20 to 30 years of recovery [Mu et al, 2016c]. Slow plant recovery has also been observed in central QTP, where vegetation cover showed no increase after 7 years of ecological protection following anthropogenic disturbance [Cai et al, 2015]. If these observations of extremely slow vegetation recovery are general in arid, mountain permafrost regions, this could substantially increase long-term net carbon emissions from QTP thermokarst features, which would not be compensated by plant and litter accumulation [Pearce et al, 2015].…”

Assessing the effects of ecological restoration approaches in the alpine rangelands of the Qinghai-Tibetan Plateau

“…As a result, about 26.3% (Δfc) of the grassland coverage showed significantly and slightly increasing trends, and only about 5.2% showed significantly and slightly decreasing trends (figure 2 and supplementary appendix figure S2). Therefore, implementation of the ecological restoration programs has increased vegetation coverage and mitigated further degradation of the grasslands (also reported by Cai et al 2015). However, due to ecological fragility of the area, the grasslands with low and very low vegetation coverage is still vulnerable to both natural and human disturbance (Jiang and Zhang 2016, Sun et al 2016, Shao et al 2017.…”

Quantitative Analysis of Terrestrial Water Storage Changes Under the Grain for Green Program in the Yellow River Basin

“…The following three land conversions (i.e., cropland to forest, cropland to grassland, and wasteland to forest) were the main types of land transformations promoted by the Grain for Green program (Yuan et al, ). The alpine meadow degradation has been found to be slowed and reversed in the Tibetan Plateau Yellow River headwaters from 2005–2012 (Bryan et al, ; Cai et al, ). Meanwhile, the GRACE‐derived TWSA has decreased in most of the YRB regions, except the upper region above the Lanzhou hydrological station (Figure c).…”