Wang Chunyu, Wang Junbang, Zhang Fawei, Yang Yongsheng, Luo Fanglin, Li Yingnian, Li Jiexia
Northwest Institute of Plateau Biology Chinese Academy of Science Xining China.
University of Chinese Academy of Sciences Beijing China.
Ecol Evol. 2022 Feb 16;12(2):e8592. doi: 10.1002/ece3.8592. eCollection 2022 Feb.
Biomass temporal stability plays a key role in maintaining sustainable ecosystem functions and services of grasslands, and climate change has exerted a profound impact on plant biomass. However, it remains unclear how the community biomass stability in alpine meadows responds to changes in some climate factors (e.g., temperature and precipitation). Long-term field aboveground biomass monitoring was conducted in four alpine meadows (Haiyan [HY], Henan [HN], Gande [GD], and Qumalai [QML]) on the Qinghai-Tibet Plateau. We found that climate factors and ecological factors together affected the community biomass stability and only the stability of HY had a significant decrease over the study period. The community biomass stability at each site was positively correlated with both the stability of the dominant functional group and functional groups asynchrony. The effect of dominant functional groups on community stability decreased with the increase of the effect of functional groups asynchrony on community stability and there may be a 'trade-off' relationship between the effects of these two factors on community stability. Climatic factors directly or indirectly affect community biomass stability by influencing the stability of the dominant functional group or functional groups asynchrony. Air temperature and precipitation indirectly affected the community stability of HY and HN, but air temperature in the growing season and nongrowing season had direct negative and direct positive effects on the community stability of GD and QML, respectively. The underlying mechanisms varied between community composition and local climate conditions. Our findings highlighted the role of dominant functional group and functional groups asynchrony in maintaining community biomass stability in alpine meadows and we highlighted the importance of the environmental context when exploring the stability influence mechanism. Studies of community stability in alpine meadows along with different precipitation and temperature gradients are needed to improve our comprehensive understanding of the mechanisms controlling alpine meadow stability.
生物量的时间稳定性在维持草原生态系统功能和服务的可持续性方面发挥着关键作用，而气候变化已对植物生物量产生了深远影响。然而，目前尚不清楚高寒草甸群落生物量稳定性如何响应某些气候因子（如温度和降水）的变化。我们在青藏高原的四个高寒草甸（海晏[HY]、河南[HN]、甘德[GD]和曲麻莱[QML]）进行了长期的野外地上生物量监测。我们发现，气候因子和生态因子共同影响群落生物量稳定性，且在研究期间只有HY的稳定性显著下降。每个站点的群落生物量稳定性与优势功能群的稳定性和功能群异步性均呈正相关。优势功能群对群落稳定性的影响随着功能群异步性对群落稳定性影响的增加而降低，这两个因素对群落稳定性的影响之间可能存在“权衡”关系。气候因子通过影响优势功能群的稳定性或功能群异步性直接或间接影响群落生物量稳定性。气温和降水间接影响HY和HN的群落稳定性，但生长季和非生长季的气温分别对GD和QML的群落稳定性有直接的负向和正向影响。其潜在机制因群落组成和当地气候条件而异。我们的研究结果突出了优势功能群和功能群异步性在维持高寒草甸群落生物量稳定性方面的作用，并且强调了在探索稳定性影响机制时环境背景的重要性。需要开展沿着不同降水和温度梯度的高寒草甸群落稳定性研究，以增进我们对控制高寒草甸稳定性机制的全面理解。
