VARIATION IN SHORELINE MACROPHYTES AND WATER QUALITY OF BEESHAZARI LAKE, CENTRAL NEPAL

Abstract

The research has been designed to examine the variation of macrophyte diversity with references to water parameters, which determines the ecological status of Beeshazari Lake (a Ramsar site). Field data were collected in two seasons (monsoon and winter) from 42 plots with 1 m x 1 m quadrat size, laid down at shoreline of the Beeshazari Lake, each plot being 30 m apart from adjacent plot along the lake perimeter for the quantitative analysis of the macrophytes. A total of 42 macrophytes (40 in monsoon and 31 in winter) were recorded during the sampling seasons. Poaceae was the dominant during both seasons, followed by Asteraceae and Euphorbiaceae families during monsoon, whereas Asteraceae and Polygonaceae were found to be dominant during winter seasons. On the basis of growth form, emergent macrophytes were dominant during both seasons. The Shannon-Weiner Diversity Index (SWI) value of macrophytes was higher during the winter (H = 0.98± 0.04) than monsoon (H = 0.97± 0.04). Lemna perpusilla (Importance Value Index, IVI = 22.8) was the dominant species during the monsoon and Azolla pinnata (IVI = 38.2) during the winter. Macrophytes species richness was positively correlated with temperature, pH, DO, and conductivity whereas negatively correlated with TDS during the monsoon season. Further, in the winter season, the richness was positively correlated with pH, DO, TDS, and electric conductivity, whereas negatively correlated with temperature.