生态学报2025，Vol.45Issue(6)：2582-2594,13.DOI:10.20103/j.stxb.202404220898
甘南亚高寒草甸不同坡位植物群落物种共存机制
Species coexistence mechanism of plant communities on different slopes of Gannan sub-alpine meadows
摘要
Abstract
The study of phylogeny and functional trait structure of plant communities is crucial for understanding mechanisms of species coexistence and biodiversity maintenance.The gradient of slope positions compresses factors such as elevation and topography within a limited vertical geographic space,thereby influencing the distribution,structure,and functionality of plants.This study focuses on the plant communities at different slope positions in the subalpine meadows of Gannan.By integrating environmental factors,community surveys,and functional trait measurements,we calculated the Net Relatedness Index(NRI),Nearest Taxon Index(NTI),and standardized effect size of the Mean Pairwise Trait Distance(SESMPD)to analyze changes in phylogenetic and functional trait structures along the slope gradient,revealing species coexistence mechanisms in Gannan's subalpine meadows.The results showed that:(1)Species richness,Shannon-Wiener index,and phylogenetic alpha diversity significantly decreased with increasing slope position(P＜0.05),while species evenness did not show a significant change(P＞0.05);(2)The overall phylogenetic structure was aggregated(NRI＞0,NTI＞0),and the coexistence of community species was mainly dominated by habitat filtration,and the NTI index showed a'V'-shaped change,indicating that habitat filtration weakened and then strengthened with the increasing of slope position,and the degree of aggregation of community phylogenetic structure likewise weakened first and then strengthened;(3)Functional trait structure shifted from a dispersed state(SESMPD＜0)in the flat and lower slope position to an aggregated state(SESMPD＞0)in the middle and upper slope position,with pronounced species interactions from flat to lower slope position and a predominance of environmental habitat filtering from middle to upper slope position;(4)Of the seven plant functional traits examined,only leaf carbon content and leaf phosphorus content showed significant but weak phylogenetic signals(P＜0.05),suggesting that evolutionary history had a minor influence on the plant communities in the study area,and that phylogenetic and functional trait patterns were not entirely consistent.In summary,niche determinism was the primary mechanism for species coexistence along the slope gradient in Gannan's subalpine meadows.Soil moisture was a relatively important environmental factor regulating the functional trait structure of plants at different slope positions.As soil moisture decreased,the functional trait structure shifted from divergence to aggregation.This study provides a more substantial theoretical basis for the mechanisms of species coexistence in the subalpine meadows of Gannan Prefecture.关键词
物种多样性/系统发育结构/功能性状结构/坡位/系统发育信号Key words
species diversity/phylogenetic structure/functional trait structure/slope position/phylogenetic signaling引用本文复制引用
张鑫,刘旻霞,陈雪娇,张盈盈,陈友艳..甘南亚高寒草甸不同坡位植物群落物种共存机制[J].生态学报,2025,45(6):2582-2594,13.基金项目
国家自然科学基金项目(31760135) （31760135）
甘肃省自然科学基金项目(20JR10RA089) （20JR10RA089）
甘肃省林业和草原科技创新与国际合作项目(KJCX2021005) （KJCX2021005）
甘肃省高校产业支撑计划项目(2023CYZC-21) （2023CYZC-21）
