The validated model preformed as a monitor, supplying the knowledge that sediment played an important role in nitrogen cycling, producing twice of the total external nitrogen load to water column. The water column bioactive nitrogen was controlled dominantly by phytoplankton assimilation, which had a nitrogen uptake rate of fifteen fold the external nitrogen loads. The bioactive nitrogen turnover rate by algal growth in this tropical water system was lower than the conditions in the other eutrophic lakes. Fifty-eight percent of the total external nitrogen load was retained via denitrification and burial processes in the Upper Peirce Reservoir.
The discovery of the systematic nitrogen transformations in tropical freshwater systems is proposed to be incorporated into future conceptual models of global nitrogen cycles.