Macroinvertebrate assemblages in relation to environments in the dongting lake, with implications for ecological management of river‐connected lakes affected by dam construction

Abstract

The Dongting Lake, a river‐connected lake, plays a vital role in people's living, agricultural production, and ecological security of the Yangtze River basin. A systematic investigation of macroinvertebrates was conducted in the Dongting Lake during May 2004 ‐ January 2005. Altogether 65 taxa belonging to 27 families and 53 genera were identified. The annual average density and biomass of total macroinvertebrates were 265 ind/m2 and 2.40 g dry mass/m2, respectively. It is demonstrated that seasonal variation existed in environmental factors structuring macroinvertebrate assemblages of the Dongting Lake. Hydrological parameters (i.e., flow velocity, water depth) were the driving factors for macroinvertebrate assemblages in spring and summer, whereas the concentrations of water nutrients (i.e., phytoplankton chlorophyll a, total dissolved phosphorus) played the leading role in governing macroinvertebrate assemblages in autumn and winter. After operation of the Three Gorges Dam in 2009, the Dongting Lake may be confronted with the threat of species diversity declining and assemblage structure changing. Thus, ecological restoration measures shall be put forward. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 914–920, 2017

Comprehensive Assessment of the Water Ecological Security of the Xiangjiang River Basin Based on Physico-Chemistry and Organism Indices

“…Water ecological security has evolved from environmental changes and ecological risk analysis. Since the International Institute for Applied Systems Analysis (IIASA) was first proposed in 1989 (Ji and Long, 2016;Pan et al, 2017), the concept of water ecological security has not been scientifically defined. At present, there are two levels of understanding of water ecological security: the generalized concept and the narrow concept (Chen and Zhou, 2005;Chen et al, 2013).…”

Response of the Downstream Braided Channel to Zhikong Reservoir on Lhasa River

“…Typically, they are distributed in wide valleys of the middle and lower reaches of plateau rivers such as Tuotuo, Dangqu, Chumar and Buqu Rivers in Yangtze River source, Maduo-Dari reach in Yellow River source, Zhaqu reach in Lancang (Mekong) River source and the middle and lower reach of Yarlung Tsangpo and Lhasa Rivers in the Qinghai-Tibet Plateau [2,[7][8][9]. Nevertheless, in recent decades, constructed large reservoirs in plateau rivers have significantly changed natural runoff, intercepted sediment and nutrients and reduced the probability of floodplain inundation in downstream riverine wetlands, leading to reduction of wetland areas and degradation of wetland functions, which may further endanger ecological balance of the region [10][11][12][13][14]. Therefore, it is essential to understand the impacts of large reservoirs on the morphological processes of downstream braided channel and riverine wetlands in the plateau rivers.…”

“…Since 1980s, extensive studies have been conducted on impacts of reservoir impoundment on riverine wetlands and aquatic ecology in low-altitude areas [13,[15][16][17][18][19]. For instance, dams affect fluvial processes and wetland ecological systems in the middle and lower Yangtze River (e.g., Dongting and Poyang Lakes), Hanjiang River, lower Yellow River, Nile River, Colorado River and many medium-sized or small rivers around the world [10,[20][21][22][23][24][25][26][27][28][29][30][31].…”