Niche and interspecific associations for dominant species in wetland herb communities in the northern branch of the Zhuozhang River Watershed, Shanxi

Based on sample investigations of wetland herb communities in the northern branch of the Zhuozhang River Watershed, we analyzed interspecies relationships and niche characteristics for 16 main species. Important findings were as follows: 1) Scirpus triqueter, Polygonum hydropiper, and Cyperus glomeratus showed tendencies of generalized species such as the largest niche breadth among dominant species; 2) a niche overlap of 55% was observed in 0 of 120 species pairs, and lower niche overlap between species indicated weaker interspecific competition; 3) Overall association of phytocoenosium was significantly negative correlation at the 0.05 level, the ratios of positive and negative associations in 2-tests and Pearson correlation coefficients were 0.52 and 0.15; therefore, the negative associations were more than the positive associations, and most interspecific associations were not significant, suggesting that wetland herb communities structure is simple, the interaction between species is weak, the communities are still under dynamic succession; 4) both association coefficients (AC)and Pearson correlation coefficients indicated niche overlap, with the fitting effect of Pearson correlation coefficient showing a stronger positive association than the AC. To provide a theoretical foundation for ecological restoration in the norther branch of the Zhuozhang River Watershed, this study integrated niche characteristics and interspecific associations to understand the dominant species, their interrelations, dynamic characteristics of the communities and current wetland utilization.