Macroinvertebrate communities and the relationships with biotic factors in river-connected lakes in the lower reaches of Yangtze River, China

Abstract

The relationships of macroinvertebrate communities with abiotic factors in lake and river system were well documented, but their relationships with biotic factors were few explored. The macroinvertebrate communities in two river-disconnected lakes (Poyang Lake and Shijiu Lake) and the rivers connected to Shijiu Lake were investigated to reveal the differences in communities and explore the relationships with biotic factors. A total of 34 species were recorded in the three water bodies. Combined with the previous study results, the dominant species in Poyang Lake is almost unchanged since 1997. Mollusks were dominated in abundance in Poyang Lake and the rivers connected to Shijiu Lake, while oligochaetes dominated the communities in Shijiu Lake. The alpha diversity indices of macroinvertebrates in Poyang Lake and the rivers connected to Shijiu Lake were distinctly higher than that of Shijiu Lake, and the beta diversity index of Shijiu Lake was the highest, supporting the rules that alpha diversity of macroinvertebrates achieves a maximum at a moderate level of connectivity and beta diversity seems to be higher when the connectivity is weaker. The differences in communities were significant between the Poyang Lake and Shijiu Lake, while the differences in the Poyang Lake and the rivers connected to Shijiu Lake were not significant. According to the results of canonical correspondence analysis (CCA), protozoon densities and phytoplankton biomass affected the distribution of macroinvertebrates in Shijiu Lake. Species number of planktonic crustaceans influenced the distribution of macroinvertebrates in rivers connected to Shijiu Lake, while species number of rotifer and densities of phytoplankton distinctly impacted on the distribution of macroinvertebrates in Poyang Lake.

Macroinvertebrate communities in the Big East Lake water network in relation to environmental factors

“…Although it is an occasional species only sampled one time, the appearance of this species has very important ecological interest. Many studies showed the upper limit of distribution of this species only reached to the Poyang lake and its surrounding lakes located in the lower reaches of Yangtze river (Wang et al, 2007;Ouyang et al, 2009;Cai et al, 2013Cai et al, , 2014Chi et al, 2016). As an estuarine and marine species, the species Nephtys sp.…”

The concept, approach, and future research of hydrological connectivity and its assessment at multiscales

“…After the connection between the rivers and the lakes was reestablished, some changes in the characteristics of each lake environments occur (Casanova et al 2009 ). River connected lakes exhibit a high degree of biodiversity, leading to an enhanced biological diversity of aquatic ecosystems (Chi et al 2016 ).…”