Community Structure of Aquatic Plants in Bung Khong Long, Nongkhai Province, A Ramsar Site of Thailand

Abstract

The community structure of aquatic plant in Bung Khong Long, a Ramsar site of Thailand was conducted during July 2001 to April 2002 to study the species diversity, density and distribution. Six 1 m² quadrates were randomly sampled in five different plant communities during three seasons. A total of 75 species, 62 genera, and 38 families was found with an average biomass of 296.50 g/m². The dominant species were Utricularia aurea, Hydrilla verticillata and Eleocharis dulcis var. dulcis with the Important Value Index (IVI) 84.66, 54.30 and 31.09%, respectively. This area had a high species diversity with H value 3.24 (Shannon-Weaver diversity index). The aquatic plants grew profusely in the rainy season especially the submerged and the free floating groups whereas the emerged and marginal groups grew profusely in summer. In the northern part of the reservoir, water surface was evenly covered by islets and free floating plants whereas the central part was the habitat of emerged plants such as Nelumbo nucifera and Nymphaea lotus. In contrast, the southern part was open water area and deeper. It was the habitat of submerged plants such as Najas sp.1 and Chara sp.1 without islets and free floating plants. A marginal plant, Caldesia sp.1 was found in the northern part. In addition, at least 34 species of aquatic plants were collected by local people for using as food, fodder and other purposes.