空间和环境因子对黄河口自然和淡水恢复湿地底栖动物群落的差异影响

生物多样性的形成和维持机制是生态学研究的核心问题，其中环境和空间因子在群落构建中的相对重要性是生态学家面临的重要挑战。为探究黄河口湿地底栖动物群落的关键影响因子，及环境和空间因子对底栖动物群落结构的相对调控作用。于2017年10月与2018年5月对黄河口湿地32个样点（淡水恢复湿地19个和自然湿地13个）的底栖动物和水体理化指标进行采集分析。非度量多维标度排序（NMDS）结果显示，黄河口淡水恢复湿地和自然湿地的底栖动物群落结构显著不同。典范对应分析（CCA）表明，影响淡水恢复湿地底栖动物群落结构的环境因子主要为电导率、盐度和氧化还原电位；而自然湿地底栖动物群落结构主要受pH和无机碳的影响；盐度是两类湿地底栖动物群落组成差异的关键因子。变差分解（VPA）结果显示，环境过滤对淡水恢复湿地底栖动物群落起主导作用；在自然湿地中，空间因子对底栖动物群落具有主要的调控作用，同时环境和空间因子的相互作用也至关重要。本研究明确了黄河口的自然和恢复湿地中环境和空间因素对底栖动物群落特征的相对作用，对黄河三角洲河口湿地中生物多样性的保护和生态系统管理提供参考。

Effects of spatial and environmental factors on benthic invertebrate communities in natural and freshwater restored wetlands of the Yellow River Delta

The underlying processes affecting community structuring in species composition is of primary importance in community ecology. The relative importance of spatial (dispersal-related) and environmental processes has been a major challenge for understanding the assembly of ecological communities. We examined the relative importance of spatial processes (dispersal-related) and environmental processes (environmental selection-related) in community structure for benthic invertebrates of estuarine wetlands in the Yellow River Delta, China. The benthic invertebrates and environmental factors were sampled and analyzed from 32 sites of estuarine wetlands (19 freshwater restored wetlands and 13 natural wetlands) in October 2017 and May 2018. The results showed that the spatial distribution of benthic invertebrate communities in estuarine wetlands presented obvious differences, and the community structure of benthic invertebrates in freshwater restoration wetlands and natural wetlands was significantly different. The Canonical correspondence analysis (CCA) results showed that the community structure of benthic invertebrates in freshwater recharge area was mainly affected by conductivity (Cond), salinity (SAL), oxidation-reduction potential (ORP) and the influential environmental factor in natural wetlands were pH and inorganic carbon (IC). And there were significant differences among environmental factors, and salinity might be the key factor causing the difference of benthic invertebrate communities'' composition between the two types of wetlands. The results of variation partitioning analysis (VPA) showed that environmental factors were more important than spatial variables in regulating benthic invertebrate communities of freshwater restoration wetlands; while in natural wetlands, spatial variables played a major role in regulating benthic invertebrate communities, and the interaction between environmental factors and environmental variables was also crucial in the community. This study clarified the relative effects of environmental and spatial factors on the characteristics of benthic invertebrate communities in the natural and freshwater restored estuarine wetlands, which can provide some reference for biodiversity protection and ecosystem management in estuarine wetlands from the Yellow River Delta.