EFFECT OF SOIL PHYSICOCHEMICAL PROPERTIES ON WETLAND HYDROPHYTIC DIVERSITY OF SAVAR AND DHANMONDI LAKE

Abstract

A study of soil physicochemical characteristics and hydrophytic diversity in four wetlands of Savar Thana and Dhanmondi Lake was performed during January to March 2007. The pH and the contents of soil moisture, organic carbon, organic mauer (Olvl), available nitrogen in ammonium (NH:) and nitrate (NOd forms, available phosphorus, sulphur, potassium (K'), calcium (ea'+) and cation exchange capacity (CEe) were determined. A total of 20 hydrophytic species were recorded. Nymphaea nouchalli, Nympliaeu pubescens, Nymphaeu rubra, Alternantheru paronychiodies, Cyperus killinga, Cyperus plarysrylis, Limnophila heterophylla, Srhoenoplectus juncodie. and Paspalidium punctutum were the rooted attached hydrophytes. Puspulidium punctatum was the most dominant (abundance = 425.0) hydrophytic species. Soil pH, organic matter, available nitrogen in ammonium (Nl-l,") form and eEe showed strong positive correlation with available nitrogen in nitrate (Na,) form (r = 0.762), organic carbon (r = 1.00" at 0.01 level of significance), ea2+ (r = 0.973), available nitrogen in ammonium (NH/) form (r = 0.66), respectively. Soil pH and organic matter showed strong negative correlation with eEe (r = -0.973' at 0.05 level of significance) and available nitrogen in ammonium (NH4+) form (r = -0.820), respectively. Dhanmondi Lake was totally devoid of rooted attached hydrophytic species.