Increasing precipitation promoted vegetation growth in the Mongolian Plateau during 2001–2018

Abstract

Taking the Mongolian Plateau as the research area, this paper studied the vegetation growth from 2001 to 2018. We quantified the vegetation growth changes based on changes in gross primary productivity (GPP) and leaf area index (LAI) and their relationships to climate variables using correlation analysis, partial correlation analysis and multiple correlation analysis. The results showed that from 2001 to 2018 both GPP and LAI showed an increasing trend, with great heterogeneities among different areas and land cover types. The largest increase of GPP and LAI occurred in the northeast plateau with the land cover types of forest and cropland. The main driving factor of vegetation growth was precipitation, while temperature was significantly negatively correlated with vegetation growth. The CO2 concentration had a significant impact on the GPP in farmland, and the increase of solar radiation had a significant impact on tundra. Our study highlights the importance of precipitation in regulating vegetation growth in the Mongolian Plateau, challenging the prevailing views that the temperature dominates the vegetation growth in the northern ecosystems.

The Effects of Precipitation Event Characteristics and Afforestation on the Greening in Arid Grasslands, China

“…Contrary to our expectation, our results showed that precipitation amount explained little to the year-by-year increase in NDVI, even in the area where vegetation growth is traditionally constrained by precipitation. Previous studies often suggested that annual precipitation amount or GSP was the predominant climatic factor controlling the spatial or temporal variations in primary production in arid grassland ecosystems [14,38,[46][47][48], although productivity was always less sensitive to precipitation in temporal models than that in spatial models [17,18,49]. However, here, we found that previous models do not always work in understanding the year-by-year changes in NDVI, in which NDVI increases significantly without the increase or even decrease in GSP over years.…”