云南省把边江流域不同土地利用方式对大型底栖动物群落的影响

研究土地利用对大型底栖动物群落的影响，对流域土地利用规划修编和河流生态修复等有重要意义。以红河上游的把边江流域为研究区，调查大型底栖动物群落现状，计算37个样点上游集水区土地利用组分、配置、多样性和水文距离4个方面20个土地利用指标，分析不同土地利用方式对大型底栖动物群落的影响。本次调查共鉴定出25个大型底栖动物分类单元，其中水生昆虫最多，占分类单元总数的72%；摄食功能群以捕食者（PR）、刮食者（SC）和直接收集者（GC）为主。把边江流域城镇用地和林地对大型底栖动物群落的影响占主导地位，而耕地对大型底栖动物群落的影响较小。影响把边江流域大型底栖动物群落的关键土地利用指标为城镇用地面积比（3PLA）、城镇用地最大斑块指数（3LPI）、城镇用地聚合指数（3AI）、城镇用地水流长度（3FLOW）、林地最大斑块指数（1LPI）和林地形状指数（1LSI）。土地利用组分、配置和水文距离是影响把边江流域大型底栖动物群落的主要方面，而土地利用多样性对大型底栖动物群落的影响较小。大型底栖动物物种密度和物种多样性与3PLA、3LPI、3AI、3FLOW和1LSI呈负相关，与1LPI呈正相关。1LPI与浮游目（如小蜉科、扁蜉科）为代表的清洁物种呈现较明显的正相关关系。城镇用地指标与SC和SH（撕食者）密度具有显著的负相关关系，与GC密度有较弱的正相关关系，而与其他功能群没有明显的相关关系。SC和SH对水质和环境条件敏感，而GC对人类干扰耐受性较强。1LPI与SC和FC（滤食收集者密度）正相关，而与PR和GC密度负相关。SC和FC对生境的完整性要求较高，而GC和PR对人为干扰和较为破碎的生境更为适应。一方面，随着城镇用地的规模、边界复杂性和聚集程度增加，研究区大型底栖动物密度和多样性降低；另一方面，随着林地完整性降低，大型底栖动物物种均匀度降低。土地利用与大型底栖动物物种多样性和功能群多样性的关系不完全一致，1LSI和3FLOW与物种多样性负相关，而与功能群多样性呈正相关关系，土地利用对物种-功能群-群落不同尺度上的影响差异还需要更深入的研究。

Impacts of different land use patterns on macrobenthic communities in the Babian River Basin, Yunnan Province

It is of great significance to study the impact of land use on macrobenthic communities for watershed land use planning revision and river ecological restoration. Taking the Babian River Basin in the upper reaches of the Red River as research area, the status of macrobenthic communities was investigated. Twenty land use indicators in 4 aspects including composition, allocation, diversity and hydrological distance based on upper catchment area of 37 sampling points were calculated to analyze the impacts of different land use patterns on macrobenthic communities. A total of 25 macrobenthic taxa were identified in this survey, of which aquatic insects accounted for 72% of the total. The main feeding functional groups were predators (PR), scrapers (SC), and gather collectors (GC). The impacts of urban land and woodland on macrobenthic communities were dominant, while the impact of agricultural land was relatively small in the Babian River Basin. The key land use indicators affecting the macrobenthic communities were the percentage of urban land (3PLA), the largest patch index of urban land (3LPI), the aggregation index of urban land (3AI), the flow length of urban land (3FLOW), the largest patch index of woodland (1LPI), and the landscape shape index of woodland (1LSI). Land use composition, allocation and hydrological distance were the main factors affecting macrobenthic communities in the Baibian River Basin, while land use diversity had little effect on macrobenthic community. The species density and diversity of macrobenthos showed negative correlations with 3PLA, 3LPI, 3AI, 3FLOW and 1LSI, while positive correlations with 1LPI. The clean species, such as Ephemeridae and Heptaglidae, increased with increasing of 1LPI. There were significantly negative correlations between the urban indexes and the density of SC and SH (Shredders), but no significant correlations between the urban indexes with other functional groups. SC and SH were sensitive to water quality and environmental conditions, however, GC were more tolerant of human interference. 1LPI was positively correlated with the density of SC and FC (Filter Collectors), but negatively correlated with the density of PR and GC. SC and FC had higher demands on habitat integrity, while GC and PR were more adaptive to human disturbance and fragmented habitat. On the one hand, with the increase of urban land use, the complexity of boundaries, and the degree of aggregation, the density and species diversity of macrobenthos in the study area decreased. On the other hand, as the integrity of woodland decreased, the species evenness of macrobenthos also decreased. The relationship between land use and macrobenthic species diversity and functional group diversity is not completely consistent, such as 1LSI and 3FLOW are negatively correlated with species diversity, but are positively correlated with functional group diversity. More in-depth researches are needed to investigate the impacts of land use on species, functional groups and communities at different scales.