Vegetation dynamics and their response to hydrothermal conditions in Inner Mongolia, China

Abstract

Inner Mongolia grassland is a sensitive area of vegetation response to climate change in China and an ecologically fragile area of terrestrial ecosystem, which is easily degraded due to the coordinated interference of natural and human factors. Therefore, it is of great practical significance to explore the spatial-temporal variation of vegetation coverage and the influence of hydrothermal conditions on its growth, to protect the regional ecological environment, to realize the sustainable development of animal husbandry and to make more reasonable and effective use of grassland resources in Inner Mongolia. In this study, linear regression, partial correlation analysis and Copula method were used to investigate the spatial patterns of NDVI internal variability and its relationship with climate change in various regions of Inner Mongolia from 1982 to 2020, and the results are as follows:(1) From 1982–2020, the surface vegetation coverage in Inner Mongolia showed an increasing trend, and the main climatic factors affecting vegetation growth in Inner Mongolia were different. In the eastern and central parts of the study area, vegetation growth is highly dependent on precipitation, while in the western part of the study area, vegetation growth is greatly affected by climate and precipitation. (2) When the temperature and precipitation of vegetation growth exceed a certain threshold, the probability of plant growth inhibition is higher. (3) NDVI variation trends of different vegetation types are also different. The meadow vegetation degraded obviously, while the marsh vegetation and desert vegetation increased obviously. (4) In addition to climate influences such as temperature and rainfall, livestock numbers and human population are the main forms of human activities accelerating grassland degradation. The results of this study can help us understand the appropriate range or types of environmental factors affecting vegetation growth in Inner Mongolia, and on this basis, we can take appropriate interventions to effectively mitigate the impact of environmental change on vegetation. • It shows an overall greening trend with great heterogeneity in space. • Precipitation and temperature interact to influence NDVI changes. • Copula function helps to quantify the influence of hydrothermal factors on NDVI changes. • NDVI correlates differently with hydrothermal factors in different regions.