Effects of climate change, coal mining and grazing on vegetation dynamics in the mountain permafrost regions

The ecological environment in alpine regions is fragile and sensitive to land-use and land-cover (LULC) change and climate warming. However, there are limited studies on the response of LULC and vegetation activity to climate change and human interference in mountainous permafrost regions. Based on in-situ meteorological and multi-source remote sensing data, we performed time trend and partial correlation analyses to investigate the spatial and temporal variation of LULC, landscape pattern, and vegetation growth under the impact of climate change and human activities in the source region of the Datong River from 2000 to 2019. Our results showed that the alpine desert area decreased significantly at a rate of -13.1 km(2) yr(-1) (p < 0.05), while the alpine meadow area increased at a rate of 8.3 km2 yr 1 (p < 0.1). Mining and road areas showed a significant increasing trend at a rate of 3.2 km(2) yr(-1) and 1.2 km(2) yr(-1), respectively. The increasing alpine meadow and mining areas were mainly derived from alpine deserts and alpine wetlands, respectively. The number of alpine wetland patches increased significantly along with a significant decrease in the landscape shape index of the rivers. Vegetation growth, as indicated by the enhanced vegetation index (EVI) was positively correlated with temperature but negatively correlated with precipitation and solar radiation in 59.6%, 52.3%, and 56.5% of the vegetated areas, respectively (p < 0.05). Temperature was the dominant climate factor controlling vegetation dynamics, and the recent warming hiatus resulted in a significant increase in EVI for alpine deserts, but no significant changes in EVI for alpine wetlands and alpine meadows. Increasing risk of negative impacts from human activities, including mineral exploration and grazing, on vegetation distribution and growth was observed. This study provides clear evidence of the upward invasion of alpine meadows into alpine desert areas under warm and humid climatic conditions. As climate warming intensifies, alpine meadow expansion may be impeded by extreme precipitation and permafrost thawing.

Automated summary

This study investigates the impact of climate change and human activities on the LULC, landscape pattern, and vegetation growth in the source region of the Datong River. The results show significant changes in alpine desert and alpine meadow areas, as well as an increase in mining and road areas. The study also reveals the correlation between vegetation growth and temperature, precipitation, and solar radiation.