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An integrated belowground trait‐based understanding of nitrogen‐driven plant diversity loss

Authors :
Qiuying Tian
Peng Lu
Xiufeng Zhai
Ruifang Zhang
Yao Zheng
Hong Wang
Bao Nie
Wenming Bai
Shuli Niu
Peili Shi
Yuanhe Yang
Kaihui Li
Dianlin Yang
Carly Stevens
Hans Lambers
Wen‐Hao Zhang
Source :
Global Change Biology. 28:3651-3664
Publication Year :
2022
Publisher :
Wiley, 2022.

Abstract

Belowground plant traits play important roles in plant diversity loss driven by atmospheric nitrogen (N) deposition. However, the way N enrichment shapes plant microhabitats by patterning belowground traits and finally determines aboveground responses is poorly understood. Here, we investigated the rhizosheath trait of 74 plant species in seven N-addition-simulation experiments across multiple grassland ecosystems in China. We found that rhizosheath formation differed among plant functional groups and contributed to changes in plant community composition induced by N enrichment. Compared with forb species, grass and sedge species exhibited more distinct rhizosheaths; moreover, grasses and sedges expanded their rhizosheaths with increasing N-addition rate which allowed them to colonize belowground habitats. Grasses also shaped a different microenvironment around their roots compared with forbs by affecting the physicochemical, biological and stress-avoiding properties of their rhizosphere soil. Rhizosheaths act as a “biofilm-like shield” by accumulating of protective compounds, carboxylic anions and polysaccharides, determined by both plants and microorganisms. This enhanced the tolerance of grasses and sedges to stresses induced by N enrichment. Conversely, forbs lacked the protective rhizosheaths which renders their roots sensitive to stresses induced by N enrichment, thus contributing to their disappearance under N-enriched conditions. This study uncovers the processes by which belowground facilitation and trait matching affects aboveground responses under conditions of N enrichment, which advances our mechanistic understanding of the contribution of competitive exclusion and environmental tolerance to plant diversity loss caused by N deposition.

Details

ISSN :
13652486 and 13541013
Volume :
28
Database :
OpenAIRE
Journal :
Global Change Biology
Accession number :
edsair.doi.dedup.....65baa632d8a371288b09d002ba904139
Full Text :
https://doi.org/10.1111/gcb.16147