Vegetation Dynamics and Diverse Responses to Extreme Climate Events in Different Vegetation Types of Inner Mongolia

Li Na,Hong Ying,Yulong Bao,Risu Na,Xiangqian Li,Yin Shan,Siqin Tong,Jiquan Zhang

doi:10.3390/atmos9100394

Abstract

As the global climate has changed, studies on the relationship between vegetation and climate have become crucial. We analyzed the long-term vegetation dynamics and diverse responses to extreme climate changes in Inner Mongolia, based on long-term Global Inventory Monitoring and Modelling Studies (GIMMS) NDVI3g datasets, as well as the eight extreme precipitation indices and six extreme temperature indices that are highly correlated with the occurrence of droughts or floods, heat or cold temperature disasters, and vegetation growth in Inner Mongolia. These datasets were analyzed using linear regression analysis, the Hurst exponent index, residual analysis, and the Pearson correlation analysis. The results showed the following: (1) The vegetation dynamical changes exhibited trends of improvement during 1982 to 2015, and 68% of the vegetation growth changes in Inner Mongolia can be explained by climate changes. (2) The extreme precipitation indices exhibited a slight change, except for the annual total wet–day precipitation (PRCPTOT). The occurrence of extreme cold temperatures showed a significant decline, while the occurrence of extreme warm temperatures showed an upward trend in Inner Mongolia. (3) The typical steppe, desert steppe, and forest steppe regions are more sensitive to extreme large precipitation, and the forest regions are more sensitive to extreme warm temperatures. (4) Extreme precipitation exhibits a one-month lagged effect on vegetation that is larger than the same-month effects on the grassland system. Extreme temperature exhibits same-month effects on vegetation, which are larger than the one-month lagged effects on the forest system. Therefore, studies of the relationship between extreme climate indices and vegetation are important for performing risk assessments of droughts, floods, and other related natural disasters.

Highlights

Extreme climate and weather events have a significant impact on the natural ecosystem and human activity [1,2,3]
This study focused on vegetation dynamics and responses to extreme climate change in different vegetation types
Slightly downward trend in vegetation was detected in the forest steppe and center of typical steppe regions, with annual change rates as low as −0.0059/a, with the area reaching 49% of the study area

Summary

Introduction

Extreme climate and weather events have a significant impact on the natural ecosystem and human activity [1,2,3]. In the environment of global warming and drying, extreme climate events (such as hot days, cold waves, heat waves, heavy rainfall, hurricanes, and droughts) have become more frequent, more widespread, and more intense [4]. Mongolia is an ecological barrier in northern China. It has been affected by extreme climate events, resulting in severe droughts, floods, and cold damage in some regions, exacerbating the already fragile grassland ecosystem. Previous studies have indicated that the temperature of Inner Mongolia significantly warmed from 1984 to 2006, with change rates of up to 0.45 ◦ C/10a. Heavy rainstorms are the most likely cause of floods, and the frequency of floods increased to a rate of

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Discussion

Conclusion