不同植物配置下人工湿地大型底栖动物群落特征及其与环境因子的关系

大型底栖动物在人工湿地生态系统的物质循环和能量流动过程中发挥着重要作用,是保持湿地结构稳定、高效运行的重要因素。为了解大型底栖动物在人工湿地内的群落特征,于2013年8月—2014年5月对盐龙湖芦苇(Phragmites communis)、茭草(Zizania latifolia)、狭叶香蒲(Typha angustifolia)表流人工湿地的大型底栖动物群落进行调查。结合相对重要性指数(IRI)、多样性指数(Shannon-Wiener多样性指数,Pielou均匀度指数,Margalef丰富度指数)与相关性分析等手段,研究了不同植物配置下人工湿地大型底栖动物群落特征及其与环境因子的关系。调查共采集到大型底栖动物14种,主要优势物种为纹沼螺(Parafossarulus striatulus)、霍普水丝蚓(Limnodrilus hoffmeisteri)、长角涵螺(Alocinma longicornis)、摇蚊幼虫(Tendipes sp.),但不同植物配置下优势物种有所差别。芦苇、茭草及狭叶香蒲湿地的年均大型底栖动物密度分别为285、330、266个/m2,年均生物量分别为25.6、104.0、32.3 g/m2。茭草湿地的大型底栖动物群落在物种数量、均匀程度上要高于芦苇及狭叶香蒲湿地,而后两者多样性水平相当。茭草湿地底栖动物群落生物量与软体动物密度呈极显著(P0.01)正相关,总密度与水深呈显著(P0.05)负相关,环节动物的密度与全氮(STN)、有机质(SOM)之间分别呈极显著(P0.01)、显著(P0.05)正相关。研究为今后人工湿地生态系统的设计、管护以及长效运行提供新的思路。

Ecological characteristics of macrobenthic communities in SFWs of different hydrophytes and their relationships with environmental factors

Macrobenthic communities play vital roles in the processes of material circulation and energy flow of constructed wetland ecosystems. These roles are also critical for sustaining the structural stability and operational efficiency of such systems. Hydrophytes are one of the most obvious biological components of constructed wetland ecosystems. However, little information is available on the differences in the macrobenthic communities that occupy different hydrophyte monoculture configurations. In the present study, a series of quarterly investigations on macrobenthic communities was carried out from August 2013 to May 2014 in surface flow wetland (SFW) monocultures of Phragmites communis, Zizania latifolia, or Typha angustifolia, Yanlong Lake, in China. The aim of this study was to explore the ecological characteristics of macrobenthic communities in SFWs of different hydrophytes and their relationships with environmental factors. Relative importance analysis, diversity index (Shannon, Pielou, Margalef) analysis, and correlation analysis were used in this study. Fourteen macrobenthic species were found (i.e., mollusk: 7, arthropod: 4, and annelida: 3). Parafossarulus striatulus, Limnodrilus hoffmeisteri, Alocinma longicornis, and Tendipes sp. were the predominant species in the study areas. The population density and biomass of these species varied according to the major hydrophyte in each SFW. The annual average density of macrobenthos in the SFWs of P. communis, Z. latifolia, and T. angustifolia was 285 ind/m², 330 ind/m², and 266 ind/m², respectively, and the annual average biomass was 25.6 g/m², 104.0 g/m², and 32.3 g/m², respectively. The highest number of species and greatest evenness among species of the macrobenthic community were found in the SFWs of Z. latifolia. These were significantly higher than those found in the SFWs of P. communis and T. angustifolia. However, there were no significant differences in the macrobenthic diversity between the SFWs of P. communis and T. angustifolia. In the SFWs of Z. latifolia, the macrobenthic biomass was significantly and positively correlated to the density of mollusks (P < 0.01), and the total density was significantly and negatively correlated to water depth (P < 0.05); the density of annelida was significantly and positively correlated to both STN (P < 0.01) and SOM (P < 0.05). This study is helpful for improving our understanding of the ecological characteristics of the macrobenthic communities in constructed wetlands and provides new insights into SFW design, management, and long-term operation.