Ecology, Environment and Conservation Paper

ASSESSMENT OF METABOLITES AND ENERGY CONTENT IN THE LEAVES OF TWO MANGROVE PLANTS, AVICENNIA MARINA AND A. OFFICINALIS AT DIFFERENT STAGES OF FOLIAGE GROWTH AND DECOMPOSITION

C.S.Tharadevi

Abstract

Different stages of foliage growth and decomposition (Vegetative leaf bud-stage Actively photosynthesizing leaf -stage II, yellow leaf-stage III, Freshly fallen mature leaf-stage IV and Decomposed leaf- stage V) of the leaves of Avicennia marina and A. officinalis were studied to gather information on the variations in the biochemical constituents. In the case of A. marina the percentage contribution due to protein increased from 20.25 to 82.81 from stage 1 toV and from 22.07 to 80.24 in A. officinalis. Carbohydrate and lipid varied between 66.1 7% and 11.68% A. marina and from 56.86% and 11.41% in A. officinalis. in In both the species lipid showed erratic variation.Total energy content increased from stage 1 to stage V but with few exceptions in one or the other stages in the two species.The total enhancement in energy recorded for both the species was above I K cal. In A. marina, a marked increase in energy due to carbohydrate could be observed with advancing stages of leaf. However, in A. officinalis a slight increment could be recorded in stage 111.The loss in energy recorded from stage 1 to V for A. marina and A. officinolis was 2366 cal and 1450 cal respectively. In the case of lipid, increment in energy was observed in both species from stage 1 to 111. Marked decline in lipid energy could be observed (approximately 50%) in both the cases as the leaves underwent decay and attack by micro fauna in the mud. High energy observed in decomposed leaves might be attributed to the long term microbial attack leading to higher biomass of microbes than the leaf matter and consequent production of detritus of high calorific and nutritive value.