湘江流域大型底栖无脊椎动物群落结构及其与环境因子的关系

采用野外调查的方法,结合Shannon多样性指数、Margalef物种丰富度指数、Pielou群落均匀度指数和冗余分析(RDA),研究了湘江流域底栖动物群落结构、多样性及其与环境因子的关系。结果表明,底栖动物3门、6纲、15目、31科、43种。其中节肢动物22种,占51.16%;软体动物16种,占37.21%;环节动物5种,占11.63%。底栖动物优势种中的霍甫水丝蚓(Limnodrilus hoffmeisteri)、方格短沟蜷(Semisulcospira cancellata)和椭圆萝卜螺(Radix swinhoei)在流域内的分布具有显著的空间差异性(P﹤0.05)。底栖动物丰度和生物量在秋季最高、冬季最低。底栖动物丰度的空间差异、季节差异均显著(P0.05),生物量的空间差异和季节差异均不显著。底栖动物群落的Shannon-Wienner指数(H')、丰富度指数(dM)和均匀度指数(J)的平均值分别为1.5145、2.0635和0.7041;湘江航电枢纽的物种多样性最高,松柏最低。RDA分析表明,重金属Cu和Cr是影响湘江流域底栖动物群落结构的关键因子,其次为石油类、Se、p H、氟化物、CODMn、COD和Zn。从种类水平看,椭圆萝卜螺可以作为湘江重金属Cr的指示物种,霍甫水丝蚓对重金属Zn敏感,格氏短沟蜷(Semisulcospira gredleri)耐受重金属Cu,耐污种类多足摇蚊(Polypedilum sp.)与COD、石油类环境轴呈正相关,前突摇蚊(Procladius sp.)与CODMn环境轴呈正相关;敏感种类扁蜉(Heptageniidae sp.)、带角螺(Angulyagra annulatus)与氟化物、COD呈负相关,四节蜉(Baetidae sp.)、闪蚬(Corbicula nitens)与CODMn呈负相关;不耐重金属类群的日本沼虾(Macrobrachium nipponense)、纹石蛾(Hydropsychidae sp.)与Cu、Cr环境轴呈负相关。

Macroinvertebrates in the Xiangjiang River: community structure and its relationship with environments

Abstract:This study aimed to explore the relationships between the community structure of macroinvertebrates, biodiversity and environmental factors in the Xiangjiang River by using field investigation method combined with Redundancy analysis and indices of Shannon, Margalef and Pielou. In this research, 43 macroinvertebrates species from 31 families, 15 orders, 6 classes and 3 phyla were collected in total, among which, 22 species (51.16% of total) were arthropods, 16 species (37.21%) were mollusks, and 5 species (11.63%) were annelids. The distributions of Limnodrilus hoffmeisteri, Semisulcospira cancellata and Radix swinhoei as dominant species had obvious spatial heterogeneity (P<0.05). Both density and biomass became maximum in autumn, while they became minimum in winter. The spatial and seasonal difference of density were significant (P<0.05), but those of biomass were not. The averages of index-Shannon, index-Margalef and index-Pielou respectively were 1.5145, 2.0635 and 0.7041. The biodiversity were highest in Xiangjiang navigation junction and lowest in Songbai. The RDA results showed that copper and chromium were the most crucial factors which influenced the community structure of macroinvertebrates. And Petroleum, selenium, pH, fluoride, permanganate index (CODMn), chemical oxygen demand (COD) and zinc also affected the community significantly. At the species level, Radix swinhoei could be indicator species for chromium pollution in the Xiangjiang River. It can also be seen that Limnodrilus hoffmeisteri was sensitive to zinc while Semisulcospira gredleri was tolerant to copper. Meanwhile, the pollution tolerant species such as Polypedilum sp. was positively correlated with the environmental axes of COD and petroleum. Procladius sp. had positive correlation with the environmental axes of CODMn. However, the sensitive species such as Heptageniidae sp. and Angulyagra annulatus were negatively correlated with Fluoride and COD. Baetidae sp. and Corbicula nitens had negative correlation with CODMn. As for Macrobrachium nipponense and Hydropsychidae sp., they were sensitive to heavy metal, which were negatively correlated with copper and chromium.