摘要
澜沧江流域独特的地质演化历史与纵向河谷的生态环境梯度变化,为研究河谷植物群落分异和群落构建过程提供了理想场所。本文以澜沧江中上游河谷植被为研究对象,综合运用TWINSPAN数量分类、群落排序和谱系结构分析方法,探讨河谷植被的群落特征及其维持机制。结果表明:(1) TWINSPAN分类将澜沧江中上游河谷植物群落划分为28个类型。样方DCA排序结果与分类结果大致相同,CCA排序和DCCA排序显示海拔是影响植被分布的主要环境因子;(2) 28个群落类型中,19个群落的净亲缘关系指数(net relatedness index,NRI)均值>0,河谷生境过滤作用明显,植物群落的谱系结构普遍呈聚集格局;(3)狭域分布于河谷的干热或干暖灌丛,如皱叶醉鱼草群落(Ass. Buddleja crispa),凹叶雀梅藤、白刺花群落(Ass. Sageretia horrida+Sophora davidii),头花香薷、灰毛莸群落(Ass.Elsholtzia capituligera+Caryopteris forrestii),华西小石积、禾草群落(Ass. Osteomeles schwerinae-Gramineae sp.),鸡骨柴、吉塘蒿群落(Ass. Elsholtzia fruticose+Artemisia gyitangensis),疏序黄荆、清香木群落(Ass. Vitex negundo f. laxipaniculata+Pistacia weinmannifolia)等,群落谱系结构呈显著聚集格局(P<0.05)。广布的植被群落类型,如滇青冈林(Ass. Cyclobalanopsis glaucoides)、云南松林(Ass. Pinus yunnanensis)、川西云杉林(Ass. Picea likiangensis var.rubescens)、白桦林(Ass. Betula platyphylla)等,群落谱系结构呈显著发散格局(P <0.05);(4)高山栲、栓皮栎群落(Ass. Castanopsis delavayi+Quercus variabilis)的群落谱系多样性(PD)均值最高,物种丰度却并非最高;(5)气候和地形方面的10个环境因子分别能够解释物种丰富度、PD指数以及NRI指数变异的40.8%、38.59%和9.97%。数量分类和排序体现了澜沧江河谷植物群落的环境分异特征,结合谱系结构分析,进一步揭示了导致河谷植被生态分异的环境因子,反映出河谷生境的多样性与复杂性。
Lancang River valley,with unique history of geological evolution and the longitudinal change of ecological environment,provides an ideal place for understanding the differentiation and assembling process of plant communities. In this study,we comprehensively used the methods of TWINSPAN quantitative classification,community ordination,and phylogenetic structure analysis to elucidate the community characteristics and maintenance mechanisms of the valley vegetation in the middle and upper reaches of Lancang River. The results showed that:( 1) According to TWINSPAN classification,plant communities in the middle and upper Lancang River valley were divided into 28 types. The result of the classification was similar to the DCA two-dimensional ranking map. CCA and DCCA ordination showed that elevation was the major environmental factor affecting vegetation distribution.( 2) Among the 28 community types,the average net relatedness index( NRI) value of 19 communities was greater than 0. The environmental filtering effect of river valley habitat was obvious. The phylogenetic structure of the plant communities generally showed an aggregation pattern.( 3) Dry-hot scrubs and dry-warm scrubs had a narrow range in the river valley,including Ass. Buddleja crispa,Ass. Sageretia horrida + Sophora davidii,Ass. Elsholtzia capituligera + Caryopteris forrestii,Ass. Osteomeles schwerinae – Gramineae sp.,Ass. Elsholtzia fruticose + Artemisia gyitangensis,Ass. Vitex negundo f. laxipaniculata + Pistacia weinmannifolia. Community phylogenetic structure generally had a significant aggregation pattern( P<0.05). The phylogenetic structure of widespread plant communities,including Ass.Cyclobalanopsis glaucoides,Ass. Pinus yunnanensis,Ass. Picea likiangensis var. rubescens,and Ass. Betula platyphylla,showed a significant divergent pattern( P<0.05).( 4) Ass. Castanopsis delavayi + Quercus variabilis had the highest average of phylogenetic diversity( PD),but species abundance was not the highest.( 5) Ten climatic and topographic factors could explain 40.8%,38.59%,and 9. 97% of the variation of species richness,PD and NRI,respectively. Environmental differentiation in the Lancang River valley was illustrated by numerical classification and ordination analysis of plant communities. Combined with the analysis of the phylogenetic structure,the environmental factors that lead to ecological differentiation of river valley vegetation were revealed,reflecting the diversity and complexity of the river valley habitats.
作者
左艳洁
戍国标
王崇云
彭明春
谢映旭
张秋媛
李富利
ZUO Yan-jie;SHU Guo-biao;WANG Chong-yun;PENG Ming-chun;XIE Ying-xu;ZHANG Qiu-yuan;LI Fu-li(Institute of Ecology and Geobotany,Yunnan University,Kunming 650091,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第9期2665-2677,共13页
Chinese Journal of Ecology
基金
云南省科技厅重大项目《云南植被志》编研项目(KCS101002)
生态环境部生物多样性调查、观测与评估项目(2019HB2096001006)资助。
关键词
澜沧江河谷
植物群落
数量分类
谱系结构
Lancang River valley
plant community
quantitative classification
phylogenetic structure