Seasonal influence of physicochemical and climatic parameters on phytoplankton diversity and abundance pattern in community managed semi-impacted floodplain wetland

Abstract

Wetlands provide numerous ecological services and are key habitats for aquatic ora and fauna. In the Beledanga wetland, the current study was conducted for three years, from July 2019 to June 2021, to evaluate the seasonal in uence of physico-chemical parameters on phytoplankton diversity and abundance patterns. Overall 48 phytoplankton taxa were observed. Group Bacillariophyceae (27%) contributed the maximum to the total phytoplankton density. The total abundance of phytoplankton was found utmost during monsoon (4.081×10 3 unit l -1 ) and least during post-monsoon (3.316×10 3 unit l -1 ). One-way ANOVA indicated signi cant seasonal differences (p<0.05) for some genera. The study gave the idea about the most in uencing physic-chemical parameters (DO, turbidity, total hardness, Ca 2+, and nitrate) on the growth of phytoplankton with the help of different multivariate and univariate analysis (Canonical correspondence analysis, Karl Pearson's correlation). The study again highlighted that climate parameters (temperature and rainfall) had some effect on the phytoplanktonic groups. Our study conceded that N: P in the studied wetland was less than the Red eld ratio (16:1) in all three seasons,while the Si:P ratio was noticed in the high range (15:1) during pre-monsoon. The value of theShannon diversity index and Margalef's species richness index were noticed to be > 3, which signi ed quite rich in phytoplankton diversity and less pollution in the ecosystem. The algal pollution index was predominant during all the seasons, indicating a high organic load which might be due to seasonal jute retting and intensi cation of agricultural farming.