Abstract: To analyze the changes of community structure and functional traits of phytoalgae on leaf surface of aquatic plants in different growing seasons, we collected samples of epiphytic algae from 10 macrophyte species in Qingshan Lake of Huangshi City in autumn (November 2022) and the following spring (May 2023). The results showed that 393 species (or variants) of epiphytic algae on the surface of the 10 macrophytes were identified, including the most diverse phylum, Bacillariophyta (199 species), followed by Chlorophyta (120 species) and Cyanobacteria (49 species). Results from both the Canonical Analysis of Principal Coordinates (CAP) and Analysis of Similarity (ANOSIM) showed significant differences in the community structure between growing seasons and across different macrophyte species. The density of epiphytic algae was the highest on submerged macrophytes, followed by emergent macrophytes and floating-leaved macrophytes. In terms of functional traits, the relative abundance of small, prostrate/adnate, non-attached, and unicellular algae was relatively high on most macrophytes. As for ecological guilds, high-profile epiphytic algae were more abundant on submerged macrophytes, whereas low-profile epiphytic algae were more abundant on floating-leaved macrophytes. In terms of the diversity of epiphytic algae, both species and functional diversity were the highest on submerged macrophytes and lowest on floating-leaved macrophytes. Higher diversity was found on macrophytes with higher leaf complexity. This study supports an understanding of the ecological functions of epiphytic algae on the surface of aquatic macrophytes with basic data, and provides references for monitoring the effectiveness of ecological restoration in Qingshan Lake.

Key words: epiphytic algae, submerged macrophyte, floating-leaved macrophyte, ecological guild, species diversity, functional diversity