Effect of flow pulsing on periphyton Sample Clauses

Effect of flow pulsing on periphyton. Slide periphyton was sampled before and after the period of high flows (described earlier in this report) to examine P uptake potential by the periphyton community, as well as potential effects of the flow pulse on enzyme activity. In contrast to expectations, P contents were lower following the flow pulse, as compared to tissue levels prior to the pulse (Figure 48). Areal biomass of periphyton on glass slides was lowest in the middle region of the PSTA Cell on both dates, with little change between dates (Figure 49). A similar trend was found for chlorophyll a (Figure 50). The enzyme activity of periphyton scraped from the slides was high for all sites on both dates, with a slight increase in activity per unit dry weight in the outflow region, relative to inflow and middle regions of the PSTA Cell (Figure 51). 6/19/2014 7/7/2014 800 600 400 200 0 Inflow Middle Outflow 6/19/2014 7/7/2014 4 3 2 1 0 Inflow Middle Outflow Slide Periphyton Areal Biomass (mg/cm2) Slide Periphyton TP (mg/kg) Figure 48. Tissue phosphorus contents in periphyton growing on glass slides, collected along internal transects within the PSTA Cell, on two dates before and after a flow pulse. Figure 49. Areal biomass of periphyton grown on glass slides along transects internal to the PSTA Cell, before and after a flow pulse. 6/19/2014 7/7/2014 3 2 1 0 Inflow Middle Outflow 6/19/2014 7/7/2014 250 200 150 100 50 0 Inflow Middle Outflow Slide Periphyton APA (µmol MUF released/g/hr) Slide Periphyton Chlorophyll (µg/cm2) Figure 50. Chlorophyll a contents for periphyton grown on glass slides along transects internal to the PSTA Cell, before and after a flow pulse.