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林业科学 ›› 2021, Vol. 57 ›› Issue (2): 126-138.doi: 10.11707/j.1001-7488.20210213

• 论文与研究报告 • 上一篇    下一篇

西藏麦地卡湿地不同水文期原生动物优势种生态位及其种间联结性

安瑞志,张鹏,达珍,乔楠茜,汤秋月,巴桑*   

  1. 西藏大学理学院青藏高原湿地与流域生态实验室 拉萨 850000
  • 收稿日期:2020-08-05 出版日期:2021-02-25 发布日期:2021-03-29
  • 通讯作者: 巴桑
  • 基金资助:
    国家自然科学基金项目(31660620);国家自然科学基金项目(21667027);西藏大学研究生"高水平人才培养计划"项目(2018-GSP-002);2019年中央财政支持地方高校发展专项资金(藏财教指[2019]1号)

Niche and Interspecific Association of Dominant Protozoan Species Under Different Hydrologic Periods in the Mitika Wetland of Tibet, China

Ruizhi An,Peng Zhang,Zhen Da,Nanqian Qiao,Qiuyue Tang,Sang Ba*   

  1. Laboratory of Wetland and Catchments Ecology in Tibetan Plateau, Faculty of Natural Sciences, Tibet University Lhasa 850000
  • Received:2020-08-05 Online:2021-02-25 Published:2021-03-29
  • Contact: Sang Ba

摘要:

目的: 探究西藏麦地卡湿地国家级自然保护区不同水文期原生动物群落优势种生态位及种间联结性,揭示不同水文期原生动物群落优势种的资源利用状况、功能地位及生态适应性等相关信息,为进一步研究麦地卡湿地原生动物群落的稳定性和空间分布格局提供依据。方法: 根据麦地卡湿地的生态环境特征、功能分区与梯度结构等特征,设置14个采样点,于2018年7月(丰水期)和10月(枯水期)用25#浮游生物网采集水样168个,运用生态位宽度、生态位重叠、生态响应速率、总体联结性、χ2检验、联结系数(AC)、共同出现百分比(PC)以及点相关系数(φ)等方法,分析优势种的生态位及种间联结性。结果: 1)麦地卡湿地丰水期共鉴定出原生动物141种,枯水期共鉴定出原生动物138种。其中优势种9种,隶属2门5属,倒卵形隐滴虫和球形砂壳虫是2个不同水文期共有优势种,优势种出现频率、丰度和优势度在不同水文期均有差异;2)麦地卡湿地原生动物优势种由广生态位种、中生态位种和窄生态位种组成,并以广生态位种占主导地位;种对间生态位重叠值差异较大,最大值和最小值分别为1和0.001,且生态位重叠程度不高,种间竞争弱;2个水文期生态响应速率之和均为正数,表明麦地卡湿地原生动物群落处于发展阶段;3)麦地卡湿地2个水文期优势种间总体上均呈显著正关联,大多数种对的关联性未达到显著水平(χ2>3.841),种间关系较为松散。结论: 在麦地卡湿地原生动物群落优势种中,丰水期的波豆虫属、枯水期的吻状隐滴虫以及2个水文期均为优势种的球形砂壳虫等对环境的适应性能力强,具有较广的生态适应幅度;而丰水期的小茄壳虫和枯水期的钟形钟虫等对水环境条件变化比较敏感,适应性较弱;部分优势种种间生态位重叠与宽度特征并不一致,如枯水期的蛋白核隐滴虫和回转隐滴虫的重叠值高但生态位宽度较小;麦地卡湿地原生动物群落物种组成和优势种等群落结构较为稳定且存在正向演替的趋势,但优势种之间以及各优势种与环境之间未达到相对的动态平衡,原生动物群落仍处于发展阶段,尚未演替至顶级阶段。

关键词: 麦地卡湿地, 原生动物, 优势种, 生态位, 种间联结, 西藏

Abstract:

Objective: This study aims to explore the niche and interspecific association of dominant species of protozoa community under different hydrologic periods in the Mitika Wetland National Nature Reserve of Tibet, China, to reveal the resource utilization status, functional status and ecological adaptability of the dominant species of protozoa community in different hydrologic periods, and to provide basis for further study on the stability and spatial distribution pattern of protozoan community in Mitika Wetland. Method: According to the characteristics of ecological environment, functional zoning and gradient structure of Mitika wetland, 14 representative sampling sites were set for sample collection. A total of 168 water samples were collected using 25 # standard plankton net in July (wet season) and October (dry season), 2018. The niche and interspecific association among the dominant species were analyzed via the niche breadth, niche overlap, ecological response rate, overall interspecific connections, χ2-test, association coefficient (AC), percentage co-occurrence (PC) and percentage point correlation (φ). Result: 1) A total of 141 species of protozoa were identified in wet season of Mitika wetland and 138 species were identified in dry season. Among them, there are 9 dominant species, belonging to 2 phyla and 5 genera. Cryptomonas obovate and Difflugia globulosa were the dominant species in two hydrological periods. The frequency, abundance and dominance of dominant species were different in different hydrological periods. 2) The dominant species of protozoa in the Mitika wetland are composed of broad niche species, medium niche species and narrow niche species, and the broad niche species were dominant. The result showed that there were significant differences in niche overlap values between species. The maximum and minimum values were 1 and 0.001, respectively. Moreover, the degree of niche overlap was not high, and the inter specific competition was weak; the sum of ecological response rates in the two hydrological periods was positive, indicating that the protozoan community was in the development stage. 3) The dominant species in the two hydrological periods of Mitika wetland were in general positively correlated with each other, however, the correlation among the most species was not significant (χ2 > 3.841), and the interspecific relationship was relatively loose. Conclusion: Among the dominant species of protozoa community in the Mitika wetland, Bodo sp. in wet season, Cryptomonas rostrata in dry season and Difflugia globulosa in the two hydrological periods have strong adaptability to the environment, and have a wide range of ecological adaptation; while Hyalosphenia minuta in wet season and Vorticella campanula in dry season are more sensitive to the changes of water environment conditions, and their adaptability is weak. The niche overlap and breadth characteristics of some dominant species are not consistent. For example, the overlap value of Cryptomonas pyrenoidifera and Cryptomonas rostrata in dry season was high, but the niche breadth was small. The species composition and dominant species structure of protozoa community in the Mitika wetland are relatively stable and have a positive succession trend, but the relative dynamic balance between dominant species and between dominant species and environment is not reached, and the protozoa community is still in the development stage and has not yet reached the top stage of succession.

Key words: Mitika wetland, protozoa, dominant species, niche, interspecific association, Tibet

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