Author(s): Xiaodong Qu; Xiaobo Liu; Wenqi Peng
Keywords: No Keywords
Abstract: Anthropogenic inputs of nutrients create environmental conditions that alter lotic ecosystem structures. Surface water total nitrogen (TN) and total phosphorus (TP) concentrations in Hun-Tai River in Northeast China represented a wide range (TN: 680 to 22600μg/L; TP: 4 to3025μg/L). The stoichiometric N: P ratio also spanning a steep gradient from 3 to 5234 (molar ratio). We conducted canonical correspondence analysis and network analysis to reveal the ecosystem structures of Hun-Tai River under the steep gradients of nutrient concentration and stoichiometry ratio in terms of three main aquatic assemblages including fish, macroinvertebrate, and benthic algae. The results showed that Hun-Tai River was heavily nutrients enriched and more P-limited. The N: P ratio was mainly affected by TP. The macroinvertebrate assemblage had the most complex network, followed by benthic algae and fish. Cyprinidae was the core fish assemblage and their distribution was mainly affected by TP. Diptera was the core macroinvertebrate assemblage and their distribution was mainly affected by TP. Diatom was the core benthic algae assemblage and their distribution was mainly affected by TN and TP. This study provided new insights into ecosystem structures of Hun-Tai River, which can contribute to ecosystem protection and management.