Effects of Aquatic Vegetation Decomposition River Nutrient Conditions: A Case Study on the Jeonjucheon River, South Korea

Aquatic vegetation plays an important role in maintaining the health of river ecosystems. However, few studies have evaluated the impact of vegetation decomposition on water quality in rivers. Therefore, we aimed to analyze the effect of aquatic vegetation decomposition on nutrient conditions in the Jeonjucheon River in South Korea. To this end, we determined the distribution and biomass of four dominant species: Phragmites japonica Steud., Phragmites australis (Cav.) Trin. ex Steud., Miscanthus sinensis Andersson, and Rumex crispus L. Additionally, we conducted a nutrient leaching experiment to determine the contributions of different species to the nutrient status of the river. We found that the decomposition concentrations of total nitrogen (TN) and total phosphorus (TP) were the highest for P. japonica (7.74 mg/L) and R. crispus (1.59 mg/L). The annual load of TN from decomposition was 536,171.6 kg/yr and that of TP was 57,547.1 kg/yr. The total pollution load for the Jeonjucheon River was 2,903,885.3 kg/yr for TN and 17,602.1 kg/yr for TP. However, the TN and TP contribution from vegetation decomposition was negligible compared to that from other sources. This study serves as a valuable reference for sustainable management of river vegetation and water pollution.