Coupled effect of climate change and human activities on the restoration/degradation of the Qinghai-Tibet Plateau grassland

Climate change (CC) and human activities (HA) are the main reasons for the restoration/degradation of the Qinghai-Tibet Plateau (QTP) grassland. Many related studies have been conducted thus far, but the impact mechanism of CC coupled with HA on QTP remains unclear. We summarized the two main coupling factors in recent years (specifically, in the past five years) and obtained the following conclusions. (1) CC and HA have positive and negative effects on the QTP grassland ecosystem. CC primarily affects grassland ecology through temperature, humidification, and extreme climate, and HA mainly affects ecosystems through primary, secondary, and tertiary industries and restoration measures. (2) CC coupled with HA affects soil, plants, animals, and fungi/microbes. CC makes the snow line rise by increasing the temperature, which expands the zone for HA. CC also restricts HA through hydrological changes, extreme climate, and outbreak of pikas and pests. Simultaneously, measures are implemented through HA to control and adapt to CC. Hence, the grassland ecosystem is comprehensively influenced by CC and HA. (3) The grassland ecosystem dynamically adapts to the disturbance caused by CC and HA by changing its physiological characteristics, distribution range, diet structure, community structure, and physical state. Simultaneously, it responds to environmental changes through desertification, poisonous weeds, rodent outbreak, release of harmful gases, and other means. This work can be used as a reference for the sustainable development of the QTP grassland.