ECOLOGICAL OBSERVATIONS IN THE FRESH WATER SWAMP FORESTS OF SOUTHERN KERALA, INDIA

Abstract

Composition, structure, diversity and edaphic attributes of three fresh water swamp forests in southern Kerala were analysed. Methodology involved establishing 0.5-ha sample plots at Kulathupuzha, Anchal and Shendurney in the Western Ghats and enumerating all trees >10 cm girth at breast height. Soil profile development, physico-chemical and electro-chemical properties of the swamp soils were also examined. The swamp vegetation exhibited lower floristic diversity than other tropical evergreen forest formations in the Western Ghats. Variations in floristic spectrum of the swamp sites studied were small. Family Myristicaceae dominated the fresh water swamps with Gymnacranthera canarica and Myristica magnifica accounting for most of the stand basal area, relative density and importance value index. Diameter and height distributions followed a negative exponential relationship. Soils were silty or sandy loams of moderate to neutral pH and modest organic C levels. N, P and K contents of the swamp soils were lower than in other forest ecosystems of the region. In situ redox potentials showed moderate levels of oxidation suggesting oxygenation of the swamp rhizosphere by knee roots.