Influence of invasive vegetation on salinity in southern coast wetlands, Sri Lanka

Abstract

Invasive plants affect overall wetland quality. This study investigates how invasive species influence soil salinity processes in lagoon-based wetlands along the southern coast of Sri Lanka. A comprehensive literature review identified soil salinity, water contamination, & distance from contamination points, including proximity to the sea & to irrigation inlet connection points, as key parameters affecting wetland water quality. Invasive plant types & invasive plant density were identified as parameters influencing invasive vegetation patterns. Wetland water-quality data were collected through soil & water sampling at selected nodes, as well as distance measurements to the nearest sea-connecting point & irrigation inlet. Invasive-plant data were gathered through field observations, interviews, & recorded data sources. The data were analysed using soil & water quality assessments, spatial distance analysis, & vegetation–spatial analysis. The wetland water-quality analysis revealed that distance from the sea-connecting point & the irrigation inlet affects wetland salinity levels. The invasive-plant analysis demonstrated an inverse relationship between soil salinity levels & invasive plant type & density, indicating that specific invasive plant species & higher plant densities correlate with increased salinity concentrations. Overall, the study confirms that invasive vegetation plays a crucial role in regulating salinity levels in wetlands.