长白山源头溪流底栖动物群落结构季节动态

源头溪流是河流生态系统物质循环和能量流动的重要区域,对底栖动物的生物多样性维持具有重要意义。目前,针对我国源头溪流底栖动物群落结构的研究薄弱,对长白山源头溪流底栖动物季节动态的研究尚未见报道。采用野外原位定量取样的方法,力图阐释长白山源头溪流底栖动物群落结构的季节动态特征及其主要环境驱动因子。研究结果表明:(1)共计采集底栖动物90个分类单元,隶属于3纲9目38科。其中,水生昆虫85属,占绝对优势。底栖动物群落结构的季节动态明显,底栖动物密度及多样性在夏、秋季显著高于冬季和春季,并在冬季达到最低值。(2)底栖动物功能摄食类群以收集者占优势,其次为撕食者、捕食者和刮食者,滤食者相对丰度最低。不同功能摄食类群的季节动态不一致,但密度和物种丰富度整体表现为秋季最高。(3)水温、凋落叶分布和流速是长白山源头溪流底栖动物群落结构季节动态的主要环境驱动因子。本研究可为长白山源头溪流后续相关研究及长白山松花江水系生态修复提供基础数据支持及参考。

Seasonal dynamics of macroinvertebrate community structure in a headwater stream in the Changbai Mountains

Headwater streams are critical locations with nutrient recycling and energy flow along a river ecosystem, posing vital significance to macroinvertebrate biodiversity maintenance in rivers. However, in China, research upon headwater streams'' macroinvertebrate community structure is few, and the report about seasonality of macroinvertebrate community structure in headwater streams of the Changbai Mountains is particularly lacking. By using in-situ sampling in the wild, we attempt to elucidate seasonality of river macroinvertebrates and the major environmental drivers behind in headwater streams of the Changbai Mountains. The results revealed:(1) A total of 90 taxa of river macroinvertebrates were identified, pertaining to 3 classes, 9 orders, and 38 families. Among which, aquatic insects (85 genera) were dominant. Seasonality of the river macroinvertebrates'' community structure was manifest, with density and diversity of the macroinvertebrates significantly higher in fall and summer than in winter and spring, reaching minimums in winter. (2) Gather-collectors were dominant functional feeding groups, and then shredders, predators, and scrapers. By contrast, filter-collectors accounted for a little part. The seasonality of different functional feeding groups indicated not in line with each other, despite density and species richness all demonstrated highest in autumn. (3) Water temperature, distribution of leaf litter, and flow velocity were major drivers of seasonal dynamics of river macroinvertebrate communities in the area. Our results may provide a support for addressing the headwater streams ecology in the Changbai Mountains, and ecological restorations of the Songhua River basins.