Benthic organic matter dynamics in Texas prairie streams

Concentrations of benthic particulate organic matter (POM) in six Texas prairie streams (2nd-4th order, intermittent and perennial) were monitored over a 20 month period to determine temporal and spatial dynamics. Benthic POM mass was highly variable, having coefficients of variation (CV) in excess of 300%. Benthic POM mass in all streams was similar with the exception of the 4th order intermittent stream which had significantly higher concentrations. Benthic POM at all sites was dominated by coarse POM (CPOM), followed by fine POM (FPOM), ultrafine POM (UPOM), and medium POM (MPOM). The dominance by CPOM is especially noteworthy in the 4th order intermittent stream where it accounted for 83% of the annual POM mass. Seasonally, benthic POM was highest in summer and lowest in the fall.