太湖湖滨带水向辐射带水生植物多样性及生境因子分析

水生植物是湖滨带水向辐射带的重要组成部分。基于2021年春季和夏季太湖湖滨带水向辐射带内水生植物调查结果，采用相关性分析和典范对应分析等方法，对水生植物分布及相应生境因子进行分析，探究其演变特征。结果表明：1）2次调查共记录太湖湖滨带水向辐射带内水生植物12种，分别属于7科9属，其中浮叶植物3种，沉水植物9种；2）相关性分析结果表明，春季水生植物群落的Alpha多样性指数与生境因子相关性不显著，夏季水生植物群落的Alpha多样性指数与水体溶解氧浓度呈极显著正相关，与透明度、透明度/水深（透明度和水深的比值）呈显著正相关，Shannon-Wiener指数、Margelef指数与总氮浓度呈显著负相关；3）典范对应分析结果表明，水体溶解氧浓度对调查结果的解释值最大，随后依次为透明度/水深以及水深。10个生境因子对水生植物分布的总解释值较低；4）与历史数据相比，本次调查结果的水生植物多样性降低且优势物种单一化，表明太湖湖滨带水向辐射带内水生植物群落结构和多样性水平受人类活动和环境因子影响较大。水生植物自然恢复周期较长，人为调控其群落结构和多样性是当前推动太湖水生植物恢复的关键。

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.