| 引用本文: | 李晓东,潘成梅,安瑞志,巴桑.西藏拉萨河中下游不同水文期浮游植物优势种生态位及种间联结性.湖泊科学,2023,35(1):118-130. DOI:10.18307/2023.0107 |
| Li Xiaodong,Pan Chengmei,An Ruizhi,Ba Sang.Niche and interspecific association of dominant phytoplankton species in different hydrological periods in the middle and lower reaches of Lhasa River, Tibet, China. J. Lake Sci.2023,35(1):118-130. DOI:10.18307/2023.0107 |
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| 西藏拉萨河中下游不同水文期浮游植物优势种生态位及种间联结性 |
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李晓东1,2, 潘成梅1,2, 安瑞志1,2, 巴桑1,2
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1.西藏大学地球第三极碳中和研究中心, 拉萨 850000;2.西藏大学理学院青藏高原湿地与流域生态系统实验室, 拉萨 850000
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| 摘要: |
| 为了探究拉萨河中下游浮游植物群落优势种生态位及种间联结性,本文选取拉萨河中下游干流及其支流作为研究地点,设置了17个样点,于2015年5月、8月和2016年11月共采集了3个水文期的水样。通过定量样品和活体观察相结合的方法鉴定浮游植物物种,使用直接计数法统计浮游植物数量,共鉴定393种,隶属于6门8纲24目48科100属。计算优势种的优势度指数(Y),运用生态位宽度、生态位重叠值和生态响应速率、总体联结性、χ2检验以及共同岀现百分比分析优势种的生态位及种间联结性。结果表明:浮游植物整体为硅藻-绿藻-蓝藻型群落特征,浮游植物优势种(Y＞0.02)共19种,均隶属硅藻门,其中尖针杆藻(Synedra acus)、双头针杆藻(S. amphicephala)等7个优势种是 3个水文期的共有优势种,优势种岀现频率和优势度在不同水文期均有差异。优势种的生态位宽度变化范围为0.089~0.751,双头针杆藻在3个水文期均为优势种且生态位宽度值均大于0.5,表现出较强的生态适应性,属广生态位种;短小曲壳藻(Achnathes exigua)种间相互竞争激烈且生境趋向于特化,可作为拉萨河中下游水域的污染指示种。19个优势种的生态位重叠值变化范围为0.001~0.966,丰水期的短小曲壳藻和普通等片藻(Diatoma aulgare)占据的生境资源相近,表现出竞争干扰,生态位重叠值为平水期>丰水期>枯水期,总体上生态位重叠程度不高,对资源的利用共性小;不同水文期优势种相对资源占有量与生态位宽度的变化基本一致,资源利用量较高的藻种大多数具较强的发展空间。通过种间联结性分析,优势种种间联结性随季节更替逐渐降低,群落中各物种种间关系从平水期-丰水期-枯水期由紧密变为松散,呈现逆向演替的趋势,大多数种对的关联性未达到显著水平(χ2>3.841),种间联结不紧密,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。 |
| 关键词: 浮游植物 生态位 种间联结性 拉萨河 |
| DOI：10.18307/2023.0107 |
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| 基金项目:国家自然科学基金项目(32070418)和2022年中央支持地方高校发展专项资金项目(藏财科教指〔2022〕1 号)联合资助。 |
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| Niche and interspecific association of dominant phytoplankton species in different hydrological periods in the middle and lower reaches of Lhasa River, Tibet, China |
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Li Xiaodong1,2, Pan Chengmei1,2, An Ruizhi1,2, Ba Sang1,2
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1.Center for Carbon Neutrality in the Earth's Third Pole, Tibet University, Lhasa 850000, P. R. China;2.Laboratory of Tibetan Plateau Wetland and Watershed Ecosystem, College of Science, Tibet University, Lhasa 850000, P. R. China
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| Abstract: |
| In order to explore the ecological niche and interspecific association of dominant phytoplankton community, we selected the middle and lower reaches of Lhasa River and its tributaries as research sites. Seventeen sampling stations were set up in May 2015, August 2015 and November 2016, and water samples were collected in three hydrological periods. A total of 393 phytoplankton species were identified, belonging to 100 genera, 48 families, 8 classes, 24 orders and 6 phyla. The dominance index (Y) of the dominant species was calculated, and the niche width, niche overlap, ecological response rate, total linkage, χ2 test and common occurrence percentage were used to analyze the niche and interspecific linkage of the dominant species. The results showed that the whole phytoplankton community was diatom-green algae-cyanobacteria. There were 19 dominant phytoplankton species (Y>0.02), all belonging to diatoms, among which 7 dominant species such as Synedra acus and S. amphicephala were common dominant species in three hydrological periods. The occurrence frequency and dominance degree of dominant species were different in different hydrological periods. The niche width of the dominant species varied from 0.089 to 0.751, and the niche width values of S.amphicephala were all larger than 0.5 in the three hydrological periods, showing strong ecological adaptability and belonging to a wide niche species. The species of Achnathes exigua were highly competitive and their habitats tended to be specialized, which could be used as an indicator of pollution in the middle and lower reaches of Lhasa River. The niche overlap values of the 19 dominant species ranged from 0.001 to 0.966, and Diatoma aulgare occupied similar habitat resources in wet season, showing competitive interference. The niche overlap values were higher in normal seasons than in dry seasons, and the niche overlap degree was not high in general. The commonness of the use of resources is small; The relative resource occupancy and niche width of dominant species in different hydrological periods were basically the same, and most of the algae species with higher resource utilization had stronger development space. According to the analysis of interspecific association, the association of dominant species decreased gradually with the change of seasons, and the interspecific relationships of species in the community changed from close to loose from normal to wet to dry seasons, showing a trend of reverse succession. The associations of most species pairs did not reach the significant level (χ2>3.841), and the interspecific association was not close. The relative dynamic balance between dominant species and environment was not reached. |
| Key words: Phytoplankton niche interspecific association Lhasa River |
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