Analysis on aquatic macrophyte diversity and environmental factors within the radiant belt toward lake of lake-terrestrial ecotone in Lake Taihu

Aquatic macrophyte plays an important role in radiant belt toward lake of lake-terrestrial ecotone. Based on the survey data of aquatic macrophyte in radiant belt toward lake of lake-terrestrial ecotone in Lake Taihu during spring and summer in 2021, by means of correlation analysis and canonical correspondence analysis (CCA), the analysis on the distribution of aquatic macrophyte and environmental factors were carried out and their evolution characteristics were explored. The results showed that: 1) A total of 12 species of aquatic macrophyte were collected in radiant belt toward lake of lake-terrestrial ecotone of Taihu Lake in the two surveys, which belonged to 7 families and 9 genera respectively and included 3 species of floating-leaved macrophyte and 9 species of submerged macrophyte. 2) The results of correlation analysis showed that there was no significant correlation between Alpha diversity index of aquatic macrophyte community and environmental factors in spring, while there was an obvious significant positive correlation between Alpha diversity index and dissolved oxygen (DO) concentration in summer, and also a significant positive correlation with transparency and the ratio of transparency to water depth. Shannon Wiener index and Margelef index had a significant negative correlation with total nitrogen concentration. 3) The CCA results showed that the DO concentration in the water body had the largest interpretation value for the survey results, followed by the ratio of transparency to water depth and water depth. The total interpretation value of 10 environmental factors of distribution of aquatic macrophyte was relatively low. 4) In contrast with prior research, the aquatic macrophyte diversity obtained was low and the dominant species were homogeneous, indicating that the structure and diversity level of the aquatic macrophyte community in radiant belt toward lake were strongly influenced by human activities and environmental factors. For the long natural recovery process, anthropogenic control in community structure and diversity was urgently needed as a key to promote the recovery of aquatic macrophytes in Lake Taihu.