Nitrogen enrichment and warming shift community functional composition via distinct mechanisms: The role of intraspecific trait variability and species turnover. (7th February 2022)

• Record Type: Journal Article
• Authors: Wang, Xiaoyi; Yan, Xuebin; Huang, Kailing; Luo, Xi; Zhang, Yuanyuan; Zhou, Luyao; Yang, Fei; Xu, Xiaohong; Zhou, Xianhui; Niu, Kechang; Guo, Hui
• Is Part Of: Functional ecology. Volume 36:Number 5(2022)
• Page Start: 1230
• Page End: 1242
• Publication Date: 2022-02-07
• Subjects: alpine meadow -- community functional composition -- functional traits -- global change ecology -- intraspecific trait variability -- nitrogen enrichment -- warming; Ecology -- Periodicals; 574.505
• DOI: 10.1111/1365-2435.14012
• Languages: English
• ISSNs: 0269-8463

Abstract

Abstract: Global change factors may shift community functional composition by driving species turnover (species occurrence and species relative abundance) and intraspecific trait variability. However, their relative contribution in determining the functional response of community to global change, especially nitrogen enrichment and warming, remains unclear. We conducted a fully factorial field experiment in a Tibetan alpine meadow to examine the responses of plant community functional composition to nitrogen enrichment and warming by quantifying seven plant functional traits in each plot. Using the sum of squares decomposition, we further disentangled the relative contribution of intraspecific trait variability and species turnover to changes in community functional composition. We found that nitrogen enrichment caused a shift of plant community towards a more resource‐acquisitive strategy, while warming resulted in a shift towards a more resource‐conservative strategy. Plant intraspecific trait variability controls shifts in community functional composition in response to nitrogen enrichment, whereas species turnover (especially change in species relative abundance) mainly explains warming‐induced shifts. Nitrogen enrichment and warming did not show significant interactive effects on plant functional composition. These findings suggest that nitrogen enrichment and warming can alter community functional composition of alpine meadow through distinct mechanisms. Plant intraspecific trait variability confers functional resilience of Tibetan alpine meadows under nitrogen enrichment, but warming could induce significant turnover of species that pronouncedly impacts community functioning in this highland ecosystem. Read the free Plain Language Summary for this article on the Journal blog. Abstract : Read the free Plain Language Summary for this article on the Journal blog. 摘要: 全球变化因子可以通过改变物种周转 (包括物种有/无和物种相对丰度) 和种内性状变异来改变群落功能组成, 但是, 它们在决定群落功能组成响应全球变化时 (尤其是氮添加和增温) 的相对贡献尚不清楚。 我们在青藏高原高寒草甸开展了氮添加和增温交互的野外试验, 通过测定每个小区里的7个植物功能性状来探究群落功能组成的响应, 同时我们利用平方和分解的方法, 揭示种内性状变异和物种周转对群落功能组成变化的相对贡献。 我们发现氮添加使植物群落向资源获取型策略转变, 而增温则使植物群落向资源保守型策略转变, 并且, 植物种内性状变异主导氮添加引起的群落功能组成的变化, 而物种周转 (主要是物种相对丰度的变化) 主导增温引起的群落功能组成的变化。氮添加与增温对植物群落功能组成没有显著的交互作用。 这些结果表明氮添加和增温可以通过不同的机制来改变群落功能组成。在氮添加下种内性状变异使得青藏高原高寒草甸具有良好的功能恢复力, 而在增温下物种会发生周转, 从而对高原生态系统的功能产生深远影响。