Long-term vegetation dynamics driven by climatic variations in the Inner Mongolia grassland: findings from 30-year monitoring

Abstract

Long-term monitoring of plant community composition and productivity provides evidence of how ecosystems respond to climate change. This study investigated the long-term (1981–2011) dynamics of plant species richness (SR) and community composition of a temperate grassland in Inner Mongolia, China, after the exclusion of livestock grazing. During the 30 years, SR increased between 1981 and 1991, and then declined from 1992 to 2011 mainly because of the loss of C3 forbs as a result of decreasing rainfall and increasing temperature. The relative abundance, measured as relative biomass (RB), of plant functional groups also showed a similar temporal pattern. There was a shift in the RB of both dominant species and functional groups. As temperature increased with decreasing rainfall during the last 20 years of the study period, the abundance of C3 forbs decreased, while C4 grasses increased. However, shrub species did not show any significant pattern in their dynamics. Redundancy analysis indicated that the species composition and plant relative abundance of the Inner Mongolian grassland were affected by both precipitation and temperature. Our findings help us better understand how grassland ecosystems respond to future climate change on the Mongolian Plateau where the climate is projected to be drier and hotter in the upcoming decades.