Influence of limnology on temporal changes in species diversity of aquatic vegetation in two tropical ponds (Kolkata, India)

Abstract

Monthly changes in species diversity of aquatic macrophytes (richness and Simpson’s diversity index) were studied in relation to various limnological predictors (including their time lag effects) of two tropical ponds, over a period of three years, using regression analysis with correction for temporal autocorrelation.The monthly mean ± SD number of total plant species was 6±2 and 2±1 in Pond 203 and Pond 206, respectively, with significant pond effect. Immediate and 2-months lag of water temperature in the ‘species rich’ pond (Pond 203) appeared to be the significant predictors for Simpson’s diversity index and total plant species richness, respectively. Secchi depth (1-month lag) was found to be the significant predictor for Simpson’s diversity index in ‘less species rich’ pond (Pond 206), while total plant species richness was not found to be influenced by any limnological predictor. Comparative literature review on maximum number of plant species per pond revealed low richness in tropical and subtropical ponds than their temperate counterparts. Among different growth forms, maximum number of emergent and submerged plant species per pond was also less in tropical climates.