Revisiting vegetation activity of Mongolian Plateau using multiple remote sensing datasets

Abstract

In-depth understanding of the changes and characteristics of vegetation activity on the Mongolian Plateau (MP) is essential to address climate change in temperate regions and even globally, but the seasonal dynamics and spatial patterns of vegetation activity have not been fully investigated. To this end, we used different types of satellite vegetation datasets from 2001 to 2020, namely, gross primary production (GPP), solar-induced chlorophyll fluorescence (SIF), and normalized difference vegetation index (NDVI), in conjunction with environmental factor datasets, then we investigated the interaction between vegetation activity of the MP and environmental factors. The spatial pattern of vegetation activity in JJA exhibited obvious spatial heterogeneity, which mainly manifested that strong vegetation activity occurred mostly in the northeast and north MP, while weak vegetation activity occurred in the southeast MP, and this pattern was closely related to hydrothermal conditions. Vegetation activity mainly exhibited an increasing or stable trend on the MP in JJA. By exploring the changes in JJA vegetation activity and its trends over the last 20 years, we found that vegetation activity in the study area is predominantly positively correlated with temperature (Tem) and negatively correlated with vapor pressure deficit (VPD) and deep soil moisture (SM). Additionally, the trends of wind speed, solar radiation, and deep SM made significant contributions to the trend in vegetation activity, suggesting that water availability has an important influence on vegetation change. Clarifying the effects of environmental factors on vegetation activity is fundamental to understanding the impact of climate change on vegetation.