Dynamic assessment of ecosystem service response and sustainable development on the Qinghai-Tibet Plateau in the context of ecological engineering

In response to the degradation of ecosystems caused by human activities and climate change, In order to protect the alpine ecosystems of the Tibetan Plateau, a number of major ecological projects have been carried out in the region since the end of the twentieth century, including the return of farmland to forests, the return of pasture to grassland, the protection of natural forests, and the construction of the Three Rivers Reserve. We integrates the United Nations' 2030 Sustainable Development Goals (SDGs) assessment framework and focuses on the ecosystem services and the SDGs as the two core indicators, to comprehensively assess the impacts on ecosystem services and sustainability of the Tibetan Plateau since the ecological projects have been implemented. The impacts of the ecological project on ecosystem services and sustainable development on the Tibetan Plateau since its implementation were comprehensively assessed, and the distribution of the key implementation areas of the ecological project under future climate and land use scenarios were explored.

As a result, since the implementation of the ecological project, the NDVI of the Qinghai-Tibet Plateau region shows an overall increasing trend, in which the areas with significant increase are concentrated in the northern and southeastern regions of the plateau, occupying 21.80% of the total area of the plateau; And the relationships among the three major groups of ecosystem provisioning services, regulating services and supporting services have maintained an overall synergistic relationship, so we suggest that the reference threshold for future implementation of ecological projects aiming at optimal provisioning of ecosystem services should be an NDVI of 0.7; Furthermore, Based on the ecosystem services contribution to SDGs (ESSDG) calculated in the framework of ‘ecosystem services-SDGs’, we found that the average ESSDG score of Qinghai-Tibet Plateau counties has increased from 40.32 to 42.42 and the spatial distribution has been higher in the southeast and higher in the northwest, and the spatial distribution has been higher in the south-east and higher in the north-west, which generally indicates that the level of development of the SDGs process on the Qinghai-Tibet Plateau is gradually higher than the level of ecosystem services provision; We also simulate four scenarios of future land use changes and three SSPs scenarios varied greatly among four climate scenarios on the Qinghai-Tibet Plateau. We draw a conclusion about the priority areas for future ecological project implementation under the different scenarios were mainly distributed in the southern and southeastern parts of the plateau.