Root trait-mediated belowground competition and community composition of a temperate steppe under nitrogen enrichment

NWIPB OpenIR

	Root trait-mediated belowground competition and community composition of a temperate steppe under nitrogen enrichment
	Zheng, Zhi; Bai, Wenming; Zhang, Wen-Hao
	2019
发表期刊	PLANT AND SOIL
卷号	437
摘要	AimsShifts of plant community composition with enhanced atmospheric nitrogen (N) deposition in grasslands have occurred globally. Despite extensive studies on the effects of enhanced N deposition on plant species composition of grassland community, few studies have focused on belowground ecological processes and duration of N addition.MethodsIn situ long-term (14-year: 2004-2017) and short-term (4-year: 2014-2017) N-addition experiments in the same sites were conducted in a temperate steppe of northern China. We investigated the effects of N-addition on plant community composition and root traits by comparing results of short-term and long-term N addition.ResultsNitrogen-evoked changes in plant community composition were primarily dependent on N-addition duration and functional groups. Short-term N addition favored growth of grasses, and depressed growth of forbs, while long-term N addition favored growth of sedges, and concurrently depressed growth of grasses and forbs, ultimately leading to a time-dependent shift of plant community composition from co-dominance by grasses and forbs to dominance by grasses, then to dominance by sedges. Similar to the observed aboveground biomass, short-term N addition led to an increase in the relative belowground biomass (the proportion of belowground biomass of individual plant to community belowground biomass) of the grass Stipa krylovii and a decrease in the relative belowground biomass of the forb Artemisia frigida, respectively. In contrast, long-term N addition enhanced the relative belowground biomass of the sedge Carex korshinskyi, and reduced the relative belowground biomass of the grass S. krylovii and the forb A. frigida. Moreover, traits of absorptive fine roots (first-two orders) in the three species (grass: S. krylovii; forb: A. frigida; sedge: C. korshinskyi) that are representatives of three functional groups differed in their responses to short-term and long-term N addition, thus rendering them differentially competitive for acquisition of belowground resource. The changes in root traits of the three species in responses to N addition of varying duration were associated with their relative aboveground biomass.ConclusionsRoot traits play important roles in mediating the competition for belowground resource and changes in plant community composition of temperate grasslands under N enrichment. Our findings provide novel insights into N-deposition-induced changes in steppe community composition by linking root traits of functional groups and duration of N addition.
关键词	Nitrogen deposition Community dynamics Functional groups Inner Mongolia steppe
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/59824
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Zheng, Zhi,Bai, Wenming,Zhang, Wen-Hao. Root trait-mediated belowground competition and community composition of a temperate steppe under nitrogen enrichment[J]. PLANT AND SOIL,2019,437.
APA	Zheng, Zhi,Bai, Wenming,&Zhang, Wen-Hao.(2019).Root trait-mediated belowground competition and community composition of a temperate steppe under nitrogen enrichment.PLANT AND SOIL,437.
MLA	Zheng, Zhi,et al."Root trait-mediated belowground competition and community composition of a temperate steppe under nitrogen enrichment".PLANT AND SOIL 437(2019).