Ecology, Environment and Conservation Paper

PLANKTON COMMUNITY DYNAMICS OF A SACRED LAKE IN THE SIKKIM HIMALAYA

Alka Jain, J. Pal, E. Sharma' and S.C. Rai

Abstract

Seasonal variation of plankton with respect to their composition, population denstiy and biomass were made in the lake water and bog of a sacred Khecheopalri lake situated in the Sikkim Himalaya.Taxonomic identification of planktonic group revealed that 48 species of pytoplankton and 18 species of zooplankton in lake and bog waterThe P/Z ratio was I .46. Similarity of species was higher in rainy season in all conditions for both phytoplankton and zooplankton, whereas highly dissimilar in winter season.The phytoplankton density was 0.75x 104 units 11 to 5.57 x 104 units 1-1 at the bog and 4.84x 104 units I' to 19.45 x I 04 units 11 in the lake conditions.The zooplankton density ranged from 0.70 x 104 units 1-1 to 2.20 x I 04 units 1 in the lake. Density of major trophic levels of the water body showed relationship with successive trophic levels but no apparent relationship was observed in terms of biomass on seasonal basis.