MSRA Webinar – Effects of Stream Restorations on Fluxes of Nutrients and Suspended Solids from Rural and Urban Streams, presented by Dr. Tom Jordan
In response to COVID-19, and in attempt to continue offering opportunities for discussion and to promote advancement of the Maryland stream restoration industry, MSRA is excited to announce a series of webinars featuring leading industry researchers and partners. The series will highlight CBT-funded pooled monitoring grant research projects. Stay tuned through our website and social media channels for the series schedule. Continuing Education Credits will be offered for these events. We hope you will join us for the sixth webinar in this series:
When: Thursday, March 25, 2021
Time: 12:00 p.m. – 1:00 p.m.
Cost: Free for members, $10 for non-members
Tom Jordan, Ph.D., is an Emeritus Scientist at the Smithsonian Environmental Research Center (SERC), Tom’s research investigates the transport and transformation of nitrogen and phosphorus in ecosystems. Since starting at SERC in 1980, he has studied the sources of nutrient releases from watersheds, the uptake of nutrients by wetlands, streams, and riparian forests, and the fates and effects of nutrients in estuaries, especially in Chesapeake Bay and its watershed. Tom has a B.S. in Biology from Bucknell University and Ph.D. in Biology from Boston University.
Presentation Abstract: Effects of Stream Restorations on Fluxes of Nutrients and Suspended Solids from Rural and Urban Streams
We monitored fluxes of nutrients and suspended solids into and out of restored reaches of an urban and a rural stream. The restorations included rock weirs installed to reconnect the eroded streams with their floodplains, prevent further erosion, and establish pools and riffles. The restored reach of the rural stream, with a watershed that is 49% forest, 37% agricultural land and 14% residential land, retained higher amounts of nutrients after restoration, retaining over 40% of the phosphate, total phosphorus (TP), ammonium (NH4), total nitrogen (TN), and total suspended solids (TSS) that entered from upstream. In contrast, the restored reach of the urban stream, in a watershed with 64% impervious surface, did not retain nutrients or TSS, except for nitrate (NO3), 70% of which was retained. In addition to measuring mass balances of fluxes in one urban restored reach, we compared discharges from five urban watersheds (31-66% impervious) that included stream restorations and various other management practices designed to reduce discharges of nutrients and TSS. We found no correlation between the discharges and total credits given for removal of TP, TN, and TSS by the management practices. Nutrient concentrations in the urban streams were relatively low, with NO3 and NH4 concentrations similar to those found in rain, except in the summer when stream NO3 declined to levels below those in rain. In one stream NH4 concentration also declined in summer. This suggests that the urban streams may be removing NO3 (and in one case NH4) from the water in summer, possibly because of the pools created in the restored reaches.