ECOLOGY OF TWO RIVERINE WETLANDS OF GOALPARA DISTRICT, ASSAM IN RELATION TO PLANKTON PRODUCTIVITY

Ecological investigation of two riverine wetlands of Goalpara district, Assam, India was carried out in relation to planktonic productivity from 2006 to 2008. The physico chemical parameters were found fluctuating with the growth of both phytoplankton and zooplankton. Both the beel was dominated by Chlorophyceae throughout the year amongst which Ulothrix and Spirogyra were found as dominating species. Among the Copepods, Cyclops was over all dominating species and amongst the Cladoceran groups; Daphnia, Bosmina and Moina were found in the wetlands throughout the studied period. Phytoplankton community of Urpod beel constituted 58.82% to 65.52%, while zooplankton community constituted 34.48% to 41.18% of the total plankton hauled throughout the studied period. Chlorophyceae fluctuates between the range of 47% to 58%, Bacillariophyceae 20% to 27% and Myxophyceae fluctuates between the ranges of 20% to 30%. Mean value of GPP in Hasila beel was estimated between the range of 2.88 gC/ m 2 /day and 4.66 gC/ m 2 /day, while in Urpod beel it was between 2.75g Cm -2 day -1 and 4.27g Cm -2 day -1 .