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

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.

The Relationship between NDVI and Climate Factors at Different Monthly Time Scales: A Case Study of Grasslands in Inner Mongolia, China (1982–2015)

“…The climate of Inner Mongolia is dominated by continental monsoon climate. The annual average temperature is between −3.7 and 11.2 • C, and the average temperature of the whole region is 6.2 • C. And the annual precipitation is between 150 and 400 mm and gradually decreases from east to west, with most precipitation occurring in June to August [10]. From East to West, the climate shows a zonal distribution.…”

“…In studies of the NDVI-climate relationship, to maintain consistency with NDVI space, most studies use the spatial interpolation method to carry out the spatial interpolation of climate factors [10,16,17,52]. However, due to the large error of the interpolation itself, if the interpolation results are used for correlation analysis, the error may be further increased [53].…”

Directional Climate Trend, Intensified Intraannual Variability, and Changes in Land Cover Drive the Dynamics of Vegetation Greenness in Peri‐Urban China During 2001–2015

“…Thus, the increase in annual precipitation also means more concentrated precipitation profile due to increased seasonality and/or extreme climate events. Increasing standard deviation of precipitation in the northern grassland zone implies more concentrated rainfall in the growing season as the average precipitation profile of the area is that most rainfall concentrates in summer (Na et al, ). On the other hand, decreased precipitation in warm‐temperate deciduous‐broadleaved forest, subtropical evergreen‐broadleaved forest, and Tibet also implies less rainfall in summer.…”

Monitoring landcover change and desertification processes in northern China and Mongolia using historical written sources and vegetation indices

“…Furthermore, there is a stronger spatial gradient of the sensitivity to and the relationship between precipitation and maximum temperature in desert steppe vegetation than in the subhumid forest zones (Li et al, 2018;Na et al, 2018). That strongly points towards the anthropogenically induced origin of local desertification processes through grazing activity after the growing season, which amplifies the vulnerability to global climate change of Inner Mongolia's grassland and steppe vegetation.…”

“…Land degradation in northern China has increased constantly since the 1950's and peaked during the 1970's and 1980's after when it decreased continuously (Feng et al, 2016). Since then, it has been frequently discussed whether desertification processes are caused by anthropogenic overstraining and particularly overgrazing activity or by climate change phenomena (Guo et al, 2020;Miao et al, 2015;Na et al, 2018;Wang et al, 2013a). Climate change and natural response cycles have been determined to trigger land degradation and desertification at variable scales.…”