Temporal and spatial distributions of macroinvertebrates and their influencing environmental factors

Liuxihe River, located in the transitional zone between the tropics and subtropics in southern China, is rich in macroinvertebrates that are characterized by species from both tropical and subtropical regions. Knowledge of the species richness and community structure provides useful information for rationalizing river ecological monitoring and assessment in this transitional zone. To explore species composition and the spatial distribution of macroinvertebrates and their relationships with environmental factors in the Liuxihe River, we sampled the macroinvertebrates and measured the environmental variables during the dry(March and December) and wet(June and September) seasons in 2018 at 20 upstream and downstream sites. We used multiple regression and multivariate ordination methods to analyze the relationships between environmental factors and macroinvertebrate communities. In total, we found 76 taxa(belonging to seven classes, 20 orders, and 50 families), among which the aquatic insects had the highest abun