Assessing Wetland Health Through Decomposition: A Case Study of Lubigi and Nambigirwa Wetlands, Uganda

The assessment of ecological functions offers a more dependable measure of the health of an ecosystem. In 2023, a study examined the decomposition process in two urban wetlands with different degree of disturbance to evaluate their health and functionality. The study also examined the influence of environmental (physicochemical) parameters on decomposition rates. 20g of <i>Pennisetum purpureum</i> was dried to a constant weight and was within litter bag decomposition experiments. Changes in leaf mass over time, leaf breakdown rates using a single exponential decay model, and wetland physicochemical characteristics (pH, temperature, TDS, Dissolved oxygen &amp; conductivity) were measured. Pearson’s correlation test was conducted to validate the relationship between the physico-chemical parameters and decomposition rates. Results revealed a significant difference in mean decomposition rates, with the degraded wetland exhibiting a higher value (0.20 kd^-1) compared to the semi-intact wetland (0.015 kd^-1). The decomposition rate was found to positively correlate with temperature, conductivity, and pH, while showing a slight negative correlation with TDS and dissolved oxygen. The study concluded that litter decomposes more rapidly in degraded wetlands, attributed to human disturbances altering their physical characteristics and that the wet-dry cycles experienced within the study areas predominantly controlled the decomposition rates.