Algal community ecology of two Rocky Mountain Front Range streams

Abstract

This study examined the composition and ecology of benthic algal communities within two streams of the Colorado Rocky Mountains. Algal community samples as well as physical and chemical habitat parameters were collected from Boulder Creek and St. Vrain Creek between July and August, 2013. Sampling began in the high elevation montane headwaters for each stream and continued downstream to the low elevation plains locations with a total of 41 samples collected. Algal communities from each stream were dominated by diatoms. Algal cell densities and species diversity were highly variable within each stream, and there was no difference in overall cell density or species diversity between the streams. Despite the close proximity of Boulder Creek and St. Vrain Creek, differences in algal community composition were found between the two streams. Differences in the algal communities between the two streams were found to be a result of higher conductivity, temperature, and pH and increased levels of total nitrogen in Boulder Creek compared to St. Vrain Creek.