Phosphorus chlorophyll relationship in temperate streams and its variation with stream catchment area

Regression analysis of a data set compiled from the literature (n = 292) showed that summer mean chlorophyll concentration (Chl) among temperate streams bore a strong (R 2 = 0.67) curvilinear relationship with summer mean total phosphorus concentration (TP). The predicted slope of the TP-Chl relationship (Chl:TP) ranged between 0.22 at TP = 50 mg·m -3 and 0.08 at TP = 1030 mg·m -3 , the highest value of TP in our data set. A bivariate model indicated that stream catchment area had a significant effect on Chl at all levels of TP and predicted a 2.3-fold increase in Chl:TP as the stream catchment area increased from 100 to 100 000 km 2 . We suggest that TP may provide a reliable basis for predicting Chl in small and large temperate streams worldwide.