| 摘要: |
| 本文于2019-2021年对金沙江上段大型底栖动物的群落结构和生态位进行了分析，以期为高海拔多沙河流的生物多样性保护提供科学数据。研究结果表明，金沙江上段大型底栖动物主要由水生昆虫组成，水生昆虫中双翅目物种占比较高。钩虾、扁蜉、襟襀、四节蜉和纹石蛾为常见种。丰水期（夏秋季）钩虾丰度占比远高于枯水期（冬春季）。研究区域基于现场观测和统计推断的物种数枯水期远高于丰水期，单站物种数以及α多样性均是干流远低于支流。四个季度总体β多样性基于物种空间周转组分的贡献率远高于物种嵌套组分的贡献率，表明在底栖动物多样性保护策略上，所有河段均具有重要保护价值。常见种的生态位宽度处于较低水平，大部分常见种之间的生态位重叠值较低，表明在较为恶劣的自然环境下，种间竞争强度较低。各站位物种的出现具有较大的随机性，随机漂流成为群落构建的主要机制。从金沙江上段梯级水库形成后的水生态保护角度出发，建议加大支流的水生态保护力度，减少宽谷河段人口集聚区村落农业面源污染和城镇点源污染负荷，提升支流钩虾和EPT分类单元的种群规模，为珍稀冷水性鱼类提供饵料来源。 |
| 关键词: 底栖大型无脊椎动物 β多样性分解 生态位宽度 生态位重叠 多样性 种间竞争 |
| DOI： |
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| 基金项目:生物多样性调查评估项目（2019HJ2096001006)、国家自然科学基金委员会区域创新发展联合基金重点支持项目（U21A2002）、国家重点研发计划项目（2017YFC0405305）、国家自然科学基金（51779158、51409178、51679152）资助 |
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| Characteristics of community structure and niche analysis of benthic macroinvertebrates in the upper reach of the Jinsha River |
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chishiyun, Hu Jun, Zheng Jinxiu, Hu Juxiang, Li Sixin, Wei Mi, Lv Keqiang, Peng jianhua
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Institute of Hydroecology, Ministry of Water Resources and Chinese Academy of Sciences
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| Abstract: |
| The community structure and ecological niche of benthic macroinvertebrates in the upper reaches of Jinsha River from 2019 to 2021, were analyzed to provide scientific data for biodiversity conservation in similar high-altitude and heavily silt-carrying rivers. The results showed that benthic macroinvertebrates in the upper section of the Jinsha River were mainly composed of aquatic insects, among which Diptera species accounted for a relatively high proportion.. The taxa such as Gammarus sp., Baetis sp., Heptagenia sp., Togoperla sp., and Hydropsyche sp. were common species. The abundance proportion of Gammarus sp. in the flood period (summer and autumn) was much higher than that in the dry period (winter and spring). The species number based on field observation and statistical inference in the study area was much higher in the dry period than in the flood period, and the single-site species number and α-diversity were both much lower in the mainstream than in the tributary. The β-diversity of the four seasons was mainly contributed by species turnover component rather than species nestedness component, indicating that all river segments had important conservation values in benthic macroinvertebrate diversity protection strategies. The ecological niche width of common species was at a low level, and the ecological niche overlap between most common species was low, indicating that under more harsh natural conditions, the intensity of interspecific competition was low. The occurrence of species at each site exhibited an obvious randomness, and random drift became the main mechanism shaping community construction. From the perspective of aquatic ecological protection after the formation of cascading reservoirs in the upper reaches of Jinsha River, it is suggested to increase the aquatic ecological protection in tributaries, reduce agricultural non-point source pollution loads in wide valleys with populated areas, enhance the population size ofGammarus sp. and EPT taxa in tributaries, providing food sources for rare cold-water fish. |
| Key words: Macroinvertebrates β-diversity decomposition nich width nich overlap diversity interspecies competition |
