亚热带丘陵区人工湿地底栖动物群落结构动态特征与水环境因子关系

底栖动物作为湿地生态系统的重要组成部分,在污染物去除与能量转化中发挥着重要作用。以湖南长沙亚热带丘陵区为研究区域,通过野外连续4年小区控制试验,系统研究浮水植物、挺水植物和无植物浅水表面流人工湿地底栖动物的群落特征及其变化,探讨其与水环境影响因子的关系。结果表明,亚热带丘陵区人工湿地底栖动物群落结构较简单,试验期内共采集到底栖动物36种,霍甫水丝蚓(Limnodrilus hoffmeisteri)为主要优势种,优势度最高可达0.5,底栖动物平均丰度为909 ind/m^(2),平均生物量为96 g/m^(2)。底栖动物物种数量、丰度和生物量均有逐年减少的趋势。底栖动物群落特征受水质和气候条件变化的双重影响,呈现出随环境变化的非稳定性特征,其中底栖动物丰度和物种数在一定程度上与NH_(3)-N、TN浓度呈显著正相关,物种丰富度和均匀度指数与水温呈显著正相关,而与pH呈负相关。但是不同类群所受的主导环境因子明显不同,其中寡毛纲与TN、NH_(3)-N呈显著正相关,而腹足纲和昆虫纲则主要与TP、COD呈显著正相关。研究表明,底栖动物对于水质变化具有显著的指示意义,同时对于强化人工湿地对污染物的消纳转化功能也具有重要生态作用,也是提升人工湿地经济效益的重要途径,值得进一步深入探索。

Relationship between dynamic characteristics of zoobenthos community structure and water environmental factors in constructed wetlands in subtropical hilly area

Benthic animals are an important component of wetland ecosystems, playing a crucial role in energy conversion and pollutant removal. A study on the subtropical hilly area of Changsha, Hunan Province was conducted to determine the community characteristics of the zoobenthos in floating plant, emergent plant, and no-plant surface flow constructed wetlands over four years of continuous field experiments. The zoobenthos community structure in constructed wetlands located in subtropical hilly areas were found to be simple, with a total of only 36 species collected during the experiment period. Limnodrilus hoffmeisteri was identified as the most dominant species, with a dominance value up to 0.5. The average abundance and biomass of zoobenthos were 909 ind/m2 and 96 g/m2, respectively. However, there was a declining trend in the number, abundance, and biomass of zoobenthos species from year to year. The characteristics of zoobenthos community were found to be influenced by both water quality and climate conditions. The abundance and number of species of the zoobenthos were positively correlated with NH3-N and TN concentrations, while the species richness and evenness index of zoobenthos had a positive correlation with water temperature but a negative correlation with pH. Different classes of zoobenthos were affected by different environmental factors; Oligochaeta had a significant positive correlation with TN and NH3-N, while Gastropoda and Insecta had a significant positive correlation with TP and COD. The results showed that zoobenthos are vital indicators of water quality change, and that they also play an important ecological role in augmenting the absorption and transformation of pollutants in CWs. Furthermore, they are a significant way to improve economic benefits in CWs and are therefore worth further study.