Freshwater Plant Diversity in Punakha District, Bhutan

Abstract

Freshwater plant diversity in different waterbodies of Punakha District was studied to determine and compare the diversity among different waterbodies, study the correlation of freshwater plant diversity with environmental variables, and to record and assess the ideas and knowledge of the locals about freshwater plants. Area based survey was used to record the plant species from a total of 80 plots, 100m2 area consisting of 4 plots of 5m × 5m from each water body. The area-based survey method directly compares the plant diversity of different waterbodies with different dimensionality and characteristics. Simpson’s diversity index, Pearson correlation, Canonical correspondence analysis and Chi Square analysis were used to analyze the diversity, correlation of the freshwater plant species with environmental variables and social data. A total of 72 freshwater plant species distributed among 57 genera and 37 families were recorded. The diversity index for the freshwater plant was found to be the highest in the ponds (0.951), followed by ditches (0.939), streams (0.928), and lakes (0.913). Correlation and Canonical correspondence analysis showed decreasing diversity with increase in water velocity, depth, and altitude. Chi Square statistics analysis showed the association of gender, age, and education level of the respondents with awareness on freshwater plants. Although the locals are aware of the benefits of freshwater plants, their awareness and knowledge did not include the vital ecological roles of the freshwater plants.