Nutrient partitioning in a clay-based surface flow wetland

A constructed, clay-based, surface flow wetland located in Byron Bay, New South Wales, Australia, was studied to determine the relative importance of living plant tissue, plant litter, sediment, and the water column as nutrient stores. The nitrogen, phosphorus and carbon contents of each nutrient compartment were determined throughout the wetland. The nitrogen and phosphorus content of the plants was higher at the inlet end of the wetland and declined with distance away from it. Nutrient levels in the sediment and water column did not vary significantly with distance through the wetland. Phosphorus concentrations in the sediments were high, but plants were shown to be responsible for the majority of nutrient accumulation from this system. The plants had failed to penetrate the clay substrate and a solid mat of adventitious roots had developed in the overlying water. In essence the plants, mainly grasses, were growing hydroponically.