The influence of hydrology and time on productivity and soil development of created and restored wetlands

In created and restored wetlands, hydrology (the depth, duration, and dynamics of water in wetlands) and time play an important role in regulating most ecological processes including productivity and soil development. The influence of hydrology on created and restored wetlands was examined using full-scale ecosystems and replicated mesocosm systems at the Olentangy River Wetland Research Park (ORWRP). In one study, twenty 540-liter tubs or 'mesocosms' were planted with either one of two wetland plants common to the region: narrow-leaved cattail (Typha angustifolia L.) or soft-stemmed bulrush ( Schoenoplectus tabernaemontani C.C. (Gmel) Palla). For each species, half the mesocosms were pumped with river water based on a monthly pulsing regime while the other half was pumped on a steady-flow regime (an even amount of water was provided weekly). Overall, Typha wetlands were significantly more productive than Schoenoplectus wetlands; however no significant differences in productivity or morphology were observed between pulsed or steady-flow wetlands among species groups. No significant differences in nutrient concentrations, uptake or uptake efficiency were detected among species groups either; however hydrology did influence plant tissue N:P ratios (P<0.01). For all wetland mesocosms, the mean (+/-1 SE) N:P ratio was 9.2+/-0.6 for steady-flow and 11.7+/-0.5 for pulsed conditions, suggesting that the steady flow wetlands were more N limited than pulsed wetlands.; A second project evaluated the restoration of flood pulses on a 5.2-ha (13-acre) bottomland forest along the Olentangy River at the ORWRP. In June 2000, the bottomland forest hydrology was restored to approximate natural flooding by cutting three breeches in an artificial levee constructed between the river and the north section of the forest and a fourth breech along the natural riverbank at the south section of the forest. Total aboveground net primary productivity (ANPP) was calculated for two sections of the forest (north and south) using estimated forest litterfall and wood production. No significant difference in mean ANPP was detected between the north section (807+/-86 g m-2 yr-1) and the south section (869+/-56 g m-2 yr-1), however productivity at the north section was substantially higher than a previous ANPP estimate conducted before restoration. A notable increase in canopy tree basal growth was noted in the south section and was primarily due to the prevalence of boxelder (Acer negundo L.) which was the dominant species in this section and showed the same shift in basal area increment during 2003 and 2004. (Abstract shortened by UMI.)...