大型底栖动物在当地生物多样性、食物链构成、水质指示和物质循环中有重要的作用, 但目前国内对森林内陆水体(湖泊、水库、溪流)中的大型底栖动物综合调查较少。作者于2019、2020年对广东车八岭国家级自然保护区的9个采样点开展了大型底栖动物的定性调查, 采样点涵盖保护区不同功能区、海拔、水体环境和水体底质。共鉴定出大型底栖动物4门6纲18目38科57种, 水生昆虫稚虫占大多数, 且多喜好清洁流动水体。在低海拔实验区即可采集到种类与数量可观的清洁水体指示物种。当地的大型底栖动物以亚热带森林典型物种为主, 多偏好栖息于流动水体, 反映了保护区的物种区系及其水体环境。本研究可为保护区的物种编目、环境评估和长期监测提供基础资料。

Aim: Zoobenthos are important components of local biodiversity, food webs, and biogeochemical circulation processes, and are important water quality indicators. Despite their recognized importance, current research on freshwater macrozoobenthic fauna in forested inland water bodies (reservoirs, lakes, streams) in China is lacking. To better understand macrozoobenthic communities and their ecosystem services in these habitats, we choose a typical subtropical forest reserve, the Chebaling National Nature Reserve for investigation.
Methods: We conducted a two-year (2019-2020) systematic field survey across nine sampling sites of different substrates in the Chebaling National Nature Reserve, Guangdong Province. These sites encompassed experimental, buffer, and core zones, and elevations stretched from 345 m to 751 m. The surveyed habitats included forested rivers, mountain streams, ponds, reservoirs, paddy fields, and ditches, which contained substrates comprising rock, gravel, sand, hardened riverbed, and silt. We applied multiple methods to survey the various habitats, including dip netting in shallow water, brushes and tweezers to isolate attached species under rocks, and baits and shrimp cages to capture species in deep water. During field surveys, we measured species composition and their population levels. We then analyzed metrics of species composition, spatial distribution, environmental indicators, and ecosystem function.
Results: In total, we identified 57 species of macrobenthic fauna (belonging to 4 phylum, 6 classes, 18 orders, and 38 families) in the reserve. Eighty percent of species were arthropods, and 90% of arthropods were aquatic insects and their nymphs. We recorded 22 species and 8 families of nymphs in Odonata (dragonflies and damselflies), which constituted 38% of all captured species. Nymphs of EPT (Ephemeroptera, Plecoptera, and Trichoptera) species constituted 22% of all species. We commonly recorded Semisulcospira libertina in various flowing water bodies, along with a considerable population of pristine water indicator species in the low-altitude experimental area.
Conclusion: Macrozoobenthic fauna in Chebaling National Nature Reserve comprised species typical of subtropical forest freshwater ecosystems. Large proportions of species that favored flowing water conditions were recorded in sites with various water bodies and elevations, and were even recorded in disturbed sites (i.e., in both experimental areas and artificial water bodies). Most species were water quality indicators that reflected the major water forms and overall quality of the reserve. The high diversity of aquatic predatory insects we recorded indicates that there is a sufficient amount of small prey in the ecosystem. Furthermore, our results suggest that the diverse and abundant macrozoobenthos can serve as considerable source of prey to predators in the reserve. Overall, our results provide data to inventory zoobenthic species and perform environmental assessments, which can further be enhanced by continued long-term monitoring of zoobenthos in the Chebaling National Nature Reserve.