Fig. 4

Shift in denitrification rates of tile (a) and surface water (b) sediments over time associated with different ratios of C:N. Denitrification rates from tile water sites are means of the Moga, Durbin, and Gully wetlands. Denitrification rates from the surface water sites are means of East Floodplain, Frog, and West Floodplain wetlands. Rates measured on Day 0 were subtracted from subsequent days assayed. Negative rates of denitrification represent a decrease in activity from Day 0. Treatments are denoted as follows: control (filled triangel), 2:1 (filled square), and 4:1 (filled circle). Wetland sediments from surface and tile water sites did not differ significantly in response to nutrient amendments