Plant and Molecular Biology
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/22641
Browse
Item Impact of climate and irrigation practices on hydrological aspects of Bundala wetlands in Sri Lanka(Irrigation and Drainage, 2023) Patabendige, K. M. K.; Amarasinghe, M. D.; Ratnayake, R. M.Bundala wetlands are the first to be declared a Ramsar wetland reserve in Sri Lanka. Two wetlands of this complex have transformed from seasonally inundated saline areas into permanent freshwater ecosystems, resulting in spatial and temporal changes that presumably have favoured plant invasions. We hypothesized that climate/rainfall changes and irrigation practices would be the most potential drivers of this change, and the objective of this research is to empirically determine the influence of rainfall and irrigation practices in the catchment on inundation pattern and plant nutrient availability that could potentially change ecology of these wetlands. Monthly rainfall data for the Bundala area (1988–2017) from Sri Lanka's meteorological department were analysed by parametric and nonparametric statistical methods, and a statistically significant change in rainfall was not discernible, confirming climate change is unlikely to be a driver to increase the lagoon water level. Irrigation data analysis revealed that these wetlands receive nearly 1.28 × 107 m3 of irrigation drainage annually from an irrigation scheme in the immediate catchment, which has resulted in decreased salinity, while inundation and plant nutrient content increased, changing the wetlands' ecology and socioeconomic status of the dependent rural communities.Item Spatial distribution and dynamics of selected mangrove forests on the east and west coasts of Sri Lanka(Sri Lanka Journal of Aquatic Sciences, 2022) De Silva, W.; Perera, K.A.R.S.; Amarasinghe, M. D.The climate and edaphic characteristics primarily determine the spatial distribution and dynamics of mangrove forests. The present study was initiated to determine how species composition and structural characteristics vary along with climate and substrate salinity of six mangrove forests located on the west coast, i.e., Negombo estuary, Chilaw lagoon, and Malwathu oya estuary, and east coast, i.e., Batticaloa lagoon, Uppar lagoon, and Urani lagoon. The structural parameters in terms of tree height, basal area, biomass, and density were obtained to determine the vegetation structure of mangrove forests. The current study found that although the structure of mangrove communities of the two coasts does not differ significantly (P<0.05), plant diversity in mangrove areas on the west coast is significantly higher than that of the east coast mangroves. In contrast, the biomass accumulation in west coast mangroves is relatively lower than that of east coast. Tree height was found to influence the productivity in terms of biomass increment of mangrove forests under investigation. As such, our study suggests that regional variations in salinity, temperature, and rainfall primarily serve as drivers of variation in mangrove species composition and vegetation structure of mangrove forests along the coasts of Sri Lanka.