Seasonal climate change drives the community intra-annual stability of a temperate grassland by altering species asynchrony in Inner Mongolia, China

Abstract

Understanding the factors that regulate the functioning of our ecosystems in response to environmental changes can help to maintain the stable provisioning of ecosystem services to mankind. This is especially relevant given the increased variability of environmental conditions due to human activities. In particular, maintaining a stable production and plant biomass during the growing season (intra-annual stability) despite pervasive and directional changes in temperature and precipitation through time can help to secure food supply to wild animals, livestock, and humans. Here, we conducted a 29-year field observational study in a temperate grassland to explore how the intra-annual stability of primary productivity is influenced by biotic and abiotic variables through time. In particular, we analyzed the relationship of community biomass intra-annual stability with plant diversity and seasonal distribution patterns of temperature and precipitation. We found that lower accumulated precipitation between June and September during the 29-year investigated contributed to lower intra-annual community stability because of a decrease in compensatory mechanisms among species (species asynchrony). Additionally, higher precipitation in July contributed to higher intra-annual stability because higher species richness with higher precipitation led to higher average intra-annual stability of all species in the community (species stability). In contrast, we found no evidence that temperature influenced community intra-annual stability. Our results indicates that ongoing reduced seasonal precipitation leading to reduced intra-annual stability in the temperate grassland, which has important theoretical significance for us to take active measures to deal with climate change.