The effects of light on the production and relative abundance of periphytic algae in the Maple River, Pellston, Michigan.

Abstract

Light is an important resource for periphytic freshwater algae. To examine the importance of this abiotic factor, we sampled algae from two areas of differing light intensity. The location was a river ecosystem in northern lower Michigan. We tested the differences in chlorophyll a production, biomass, and relative abundance of different genera of algae between an open site and a shaded site. We found that greater light led to greater production in the form of chlorophyll a and biomass. Pennate diatoms were the dominant type of periphytic algae in both areas, and thus the major contributors to the total production in the river. We also found that relative abundance of pennate diatoms was uniform between sites, whereas certain other algae seemed to prefer one of the two areas.