Seasonal dynamics of wetland flora in response to physico-chemical parameters of Pravas Wetland, Palpa, Nepal

Abstract

The wetland plant communities are effective indicators of wetland status. The fluctuations in seasonal environmental factors and water quality exert a significant influence on the growth and proliferation of aquatic species in freshwater ecosystems. The relationships between the seasonal variation of physico-chemical parameters and the diversity of plant species were investigated in Pravas wetland using correlation analysis and CCA. Seven water quality parameters were selected and analyzed from different 32 sampling points. A wooden framed quadrat of sized (1m×1m) was laid down for species sampling. The presented flora was evaluated by species composition, species richness and the ecological indices. Total of 73 plant species were recorded with the dominancy of emergent species, Poaceae was the dominant family followed by Cyperaceae and Asteraceae in two seasons. Shannon- Weiner Index was high during post-monsoon season than pre-monsoon. Digitaria species was dominant during the post-monsoon and Cynodon dactylon was dominant during pre-monsoon season. Among all studied characteristics, temperature and phosphorous were the most responsible characters affecting the species abundance during both post and premonsoon season. The physico-chemical characteristics of the water (temperature and

dissolved oxygen) exhibited significant variations between the seasons with the change

in species composition. The post-monsoon season was found to be more favourable for

macrophyte

growth due to the flushing of nutrients through high rainfall. It was revealed that the wetland plant diversity was changed accordance with the season with the change in nutrient level in the water quality. The prevalence of emergent indicates an escalation in increasing productivity of the lake ecosystem.