Applicability of Phosphorus Budget Models to Small Precambrian Lakes, Algonquin Park, Ontario

Abstract

Phosphorus and hydrological budgets were constructed for four small lakes with Precambrian drainage in Algonquin Park, Ontario. Lake outflow discharge ranged from 21.7 × 105 to 177 × 105 m3∙yr−1. Annual phosphorus input to the lakes from terrestrial drainage and precipitation totaled 36.3–188 kg∙yr−1. The lakes retained 16–41% of the annual input. These data were used to test a series of models that predict the spring total phosphorus concentration in lake water and the mean summer chlorophyll a. The predicted spring phosphorus concentration agreed well with measured values (within 1.3 mg∙m−3) except where human-associated phosphorus input may have contributed to the phosphorus budget of the lake. Agreement between predicted and measured chlorophyll a was not as close. A figure of 0.48 kg P∙capita−1∙yr−1 was calculated as the human-associated supply. Key words: phosphorus budget, chlorophyll a, predictive model, Precambrian lake