中国北方沿海城市河流底栖生物群落结构特性研究

Study on Community Structure Characteristics of Benthic Organisms in Rivers of Northern Coastal Cities of China

摘要: 河流具有提供水源、维持生物多样性、保障生态稳定和支撑社会发展等关键功能。城市河流是其中生物多样性保护和水质净化的重点区域。目前中国北方沿海城市河流与一般河流相比，具有“短小、急促”的自然特点，使其生态系统更脆弱，并伴有潮汐扰动与城市化污染叠加导致生境异质性改变与自净能力衰退等问题，本研究通过现场勘探调查，将研究区域生境划分为三种生境，分成三个季节采样，分析各类生境水环境指标和底栖动物群落结构特征，旨在建立不同生境评估体系，为生态修复提供靶向支撑。本研究以烟台市内夹河和柳子河流域为对象，布设共24个采样点，覆盖了感潮、城市及半自然河段，于2022年夏、秋、冬三季采集水样和底栖生物样本(涵盖4门48种)。基于水动力梯度划分生境类型，采用综合污染指数评价水质，结合Margalef丰富度指数、Shannon-Wiener多样性指数和BI生物指数分析群落结构，通过Pearson相关性解析环境因子影响。研究区域水质整体呈重度污染(综合污染指数P > 1.0)，柳子河污染程度高于内夹河，城市河段冬季污染最显著。底栖动物群落呈现时空分异：半自然河段多样性最高(Margalef指数1.53)，以节肢动物为主；城市河段耐污物种占优(BI指数8.26)，栖息密度冬季达4104 ind/m²。

Abstract: Rivers play critical roles in providing water resources, maintaining biodiversity, ensuring ecological stability, and supporting social development. Urban rivers, in particular, are key areas for biodiversity conservation and water quality purification. Compared to general rivers, those in northern coastal cities of China are characterized by their “short length and swift flow,” which renders their ecosystems more vulnerable. These systems face challenges such as altered habitat heterogeneity and diminished self-purification capacity due to combined pressures of tidal influences and urban pollution. This study conducted field surveys and divided the study area into different habitat zones based on in-situ habitat conditions and urbanization levels. Sampling was carried out over three seasons to analyze spatial variations in water quality across river sections, investigate the structural characteristics of benthic macroinvertebrate communities, and perform a biological assessment of water quality. Furthermore, the structure and properties of microbial communities were analyzed. The aim is to establish a zoning-based assessment framework to provide targeted support for ecological restoration. This study was carried out in the Neijia River and Liuzi River basins, Yantai City, China. Twenty-four sampling sites, covering tidal, urban, and semi-natural reaches, were established. Water and benthic macroinvertebrate samples (comprising 48 species from 4 phyla) were collected seasonally in summer, autumn, and winter of 2022. Habitat types were first classified based on hydrodynamic gradients. Water quality was assessed using a comprehensive pollution index. For analyzing the benthic community structure, the Margalef richness index, Shannon-Wiener diversity index, and the Biotic Index (BI) were integrated. Furthermore, Pearson correlation analysis was employed to elucidate the influences of environmental factors. The assessment revealed severe overall pollution in the study area (comprehensive pollution index, P > 1.0). Pollution was more pronounced in the Liuzi River compared to the Neijia River, with urban reaches exhibiting the highest pollution levels, particularly during winter. Spatiotemporal heterogeneity was evident in the benthic macroinvertebrate community. The highest diversity (Margalef richness index: 1.53) was recorded in semi-natural reaches, where arthropods constituted the dominant group. In contrast, urban reaches were dominated by pollution-tolerant species (Biotic Index, BI: 8.26), with a peak habitat density of 4104 individuals per square meter (ind/m²) in winter.