生物多样性 ›› 2017, Vol. 25 ›› Issue (1): 34-45.DOI: 10.17520/biods.2016166

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艾比湖流域杜加依林荒漠植物群落多样性及优势种生态位

龚雪伟1,2, 吕光辉1,3,*()   

  1. 1 绿洲生态教育部重点实验室, 乌鲁木齐 830046
    2 新疆大学资源与环境科学学院, 乌鲁木齐 830046
    3 新疆大学干旱生态环境研究所, 乌鲁木齐 830046;
  • 收稿日期:2016-06-23 接受日期:2016-10-31 出版日期:2017-01-20 发布日期:2017-02-08
  • 通讯作者: 吕光辉
  • 基金资助:
    国家自然科学基金(31560131)

Species diversity and dominant species’ niches of eremophyte communities of the Tugai forest in the Ebinur basin of Xinjiang, China

Gong Xuewei1,2, Lü Guanghui1,3,*()   

  1. 1 Key Laboratory of Oasis Ecology of Ministry of Education, Urumqi 830046
    2 College of Resource and Environment Sciences, Xinjiang University, Urumqi 830046
    3 Institute of Arid Ecology and Environment, Xinjiang University, Urumqi 830046
  • Received:2016-06-23 Accepted:2016-10-31 Online:2017-01-20 Published:2017-02-08
  • Contact: Lü Guanghui

摘要:

多样性格局的形成是物种间相互作用及其适应环境的结果。为了阐释艾比湖流域荒漠植物的物种多样性及优势种生态位特征, 我们对艾比湖湿地国家级自然保护区内阿其克苏河北岸的杜加依林进行了物种组成与环境因子调查。结果表明: (1)按照土壤水盐含量, 根据多元回归树(multivariate regression tree, MRT)方法可将植被划分为胡杨-罗布麻-芦苇(Ass. Populus euphratica - Apocynum venetum - Phragmites australis) (I型)、胡杨-琵琶柴(Ass. Populus euphratica - Reaumuria songonica) (II型)和盐爪爪‖胡杨-罗布麻+骆驼刺(Ass. Kalidium foliatumPopulus euphratica - Apocynum venetum + Alhagi sparsifolia) (III型) 3个主要群丛。(2) I型群丛抵御极端环境的能力较差, 包括5个样方, II型群丛能够忍受轻微的盐旱胁迫, 包括3个样方, III型群丛对盐旱生境具有一定的适应性, 包括22个样方; 随着典型群丛从I型演替成为III型, 沙生和盐生植物逐渐占据生境并成为主要优势种, Shannon-Wiener多样性指数(H)和Margalef丰富度指数(Ma)先降低后增加, Simpson优势度指数(C)和Pielou均匀度指数(E)先增加后逐渐降低, 体现了杜加依林植物群落的演替序列。(3)生态位宽度Bray-Curtis相似性聚类分析将13个优势种分为2组, 平均相似性分别为96.89%和97.66%, 反映了研究区物种生态位宽度具有较高的相似性; 基于物种多度数据的非度量多维标度排序(NMDS)压力系数为0.04, 除铃铛刺(Halimodendron halodendron)与甘草(Glycyrrhiza uralensis)外, 物种之间的分布也具有较高的相似性。综上所述, 土壤水盐含量是影响艾比湖流域杜加依林中荒漠植物群丛结构及多样性的主要环境因子, 并决定了群落的演替方向; 各优势种之间的生态位和分布具有较高的相似性, 存在明显的竞争关系。

关键词: 荒漠河岸林, 多元回归树, 非度量多维标度排序, 生态位宽度, 生态位重叠

Abstract:

Patterns of species diversity are determined by both species interactions and environmental adaptations. The species composition and environmental factors of the Tugai forest on the north shore of the Aqikesu River was investigated to determine species diversity and the ecological niche of dominant species in the Ebinur basin. Using a multivariate regression tree based on the content of soil water and salinity, our results showed that the plant communities were divided into three associations. The three associations are the Ass. Populus euphratica - Apocynum venetum - Phragmites australis (type I), the Ass. Populus euphratica - Reaumuria songonica (type II), and the Ass. Kalidium foliatumPopulus euphratica - Apocynum venetum + Alhagi sparsifolia (type III). Association I had a weak ability to tolerate extreme environments, including 5 quadrats, while Association II could tolerate mild salt and drought stress, including 3 quadrats, and Association III had a certain degree of adaptability to salty and dry habitats, including 22 quadrats. With succession of typical associations from type I to III, psammophytes and halophytes gradually occupied the habitats and become the dominant species. The Shannon-Wiener biodiversity index and Margalef richness index initially decreased and then increased along with environmental degradation, while the Simpson dominance index and Pielou evenness index showed the opposite trend. The variation of associations and species diversity along the environmental gradient reflects the succession of plant communities. The Bray-Curtis similarity analysis of niche breadth clustered 13 dominant species into two groups, with an average similarity of 96.89% and 97.66%, respectively, reflecting that the niche breadth of species has a high similarity. The pressure coefficient of non-metric multidimensional scaling (NMDS) ordination was 0.04 and except for Halimodendron halodendron and Glycyrrhiza uralensis, and species distribution also had a high similarity. In summary, soil water and salt contents are the main environmental factors that are responsible for plant structure and diversity, and determine the direction of succession. The niche and distribution of dominant species show high similarity, indicating obvious competitive relationship between them.

Key words: desert riparian forest, multivariate regression tree, non-metric multidimensional scaling, ecological niche breadth, ecological niche overlap