The maximum growth rates and the relative abundances of several benthic diatom species grown at various concentrations of NO3-N.

Abstract

The maximum growth rates of 10 species of diatoms from the East Branch of the Maple River in northern Michigan were determined by sampling algal populations grown in artificial streams with varying levels of nitrogen. The maximum growth rates were found to be significantly different among the species. These values were then compared to the relative abundances of each of the species. Species' abundances were not found to be significantly correlated with their maximum growth rates. I concluded that factors other than growth rates, such as export and import of cells and interspecific competition, must determine the abundances of each of the species in the population.