Amanda M. Nahlik

Creating Wetlands: Primary Succession, Water Quality Changes, and Self-Design over 15 Years

The succession of vegetation, soil development, water quality changes, and carbon and nitrogen dynamics are summarized in this article for a pair of 1-hectare flow-through-created riverine wetlands for their first 15 years. Wetland plant richness increased from 13 originally planted species to 116 species overall after 15 years, with most of the increase occurring in the first 5 years. The planted wetland had a higher plant community diversity index for 15 years, whereas the unplanted wetland was more productive. Wetland soils turned hydric within a few years; soil organic carbon doubled in 10 years and almost tripled in 15 years. Nutrient removal was similar in the two wetlands in most years, with a trend of decreased removal over 15 years for phosphorus. Denitrification accounted for a small percentage of the nitrogen reduction in the wetlands. The wetlands were effective carbon sinks with retention rates of 1800–2700 kilograms of carbon per hectare per year, higher than in comparable reference wetlands and more commonly studied boreal peatlands. Methane emission rates are low enough to create little concern that the wetlands are net sources of climate change radiative forcing. Planting appears to have influenced carbon accumulation, methane emissions, and macrophyte community diversity.

The effect of river pulsing on sedimentation and nutrients in created riparian wetlands.

Sedimentation under pulsed and steady-flow conditions was investigated in two created flow-through riparian wetlands in central Ohio over 2 yr. Hydrologic pulses of river water lasting for 6 to 8 d were imposed on each wetland from January through June during 2004. Mean inflow rates during pulses averaged 52 and 7 cm d(-1) between pulses. In 2005, the wetlands received a steady-flow regime of 11 cm d(-1) with no major hydrologic fluctuations. Thirty-two sediment traps were deployed and sampled once per month in April, May, June, and July for two consecutive years in each wetland. January through March were not sampled in either year due to frozen water surfaces in the wetlands. Gross sedimentation (sedimentation without normalizing for differences between years) was significantly greater in the pulsing study period (90 kg m(-2)) than in the steady-flow study period (64 kg m(-2)). When normalized for different hydrologic and total suspended solid inputs between years, sedimentation for April through July was not significantly different between pulsing and steady-flow study periods. Sedimentation for the 3 mo that received hydrologic pulses (April, May, and June) was significantly lower during pulsing months than in the corresponding steady-flow months. Large fractions of inorganic matter in collected sediments indicated that allochthonous inputs were the main contributor to sedimentation in these wetlands. Organic matter fractions of collected sediments were consistently greater in the steady-flow study period (1.8 g kg(-1)) than in the pulsed study period (1.5 g kg(-1)), consistent with greater primary productivity in the water column during steady-flow conditions.

Erratum to: Methane Emissions from Created Riverine Wetlands

P.783, L.7-8: “19 and 68 g CH4-C m −2 y” should read “13 and 47 g CH4-C m −2 y” P.783, L.8-9: “6 and 17 g CH4-C m −2 y” should read “4 and 12 g CH4-C m −2 y” P.783, L.17: “82 g CH4-C m −2 y” should read “57 g CH4-C m −2 y” P.783, L.20: “4 g CH4-C m −2 y” should read “1 g CH4-C m y” P.783, L.20: “16 gCH4-C m −2 y” should read “7 g CH4-C m y” Results P.786, L.80: “19 (68) and 6 (17) g CH4-C m −2 y” should read “13 (47) and 4 (12) g CH4-C m −2 y” P.787, L.1: “80 (151) mg CH4-C m −2 d” should read “55 (105) mg CH4-C m −2 d” P.787, L.1-2: “more than 4 times higher” should read “more than 2 times higher” P.787, L.3: “more than 8 times higher” should read “more than 6 times higher” P.787, L.7: “135 (277) and 87 (297) mg CH4-C m −2 d” should read “94 (192) and 60 (206) mg CH4-C m −2 d” P.787, L.12-13: “37 (122) mg CH4-C m −2 d” should read “25 (85) mg CH4-C m −2 d” P.788, L.14: “approximately 3 mg CH4-C m −2 d” should read “approximately 2 mg CH4-C m −2 d” P.788, L.36: “3 (0.1) mg CH4-C m −2 d” should read “2 (0.1) mg CH4-C m −2 d” P.788, L.39-40: “37 (36) mg CH4-C m −2 d and 77 (160) mg CH4-C m −2 d” should read “26 (25) mg CH4-C m d and 53 (111) mg CH4-C m −2 d” P.788, L.49-50: “23 (82) g CH4-C m −2 y—the mean rate of which is over 2.5 times” should read “16 (57) g CH4-C m −2 y—the mean rate of which is over 15%” Table 1 Methane Emission (g CH4-C m −2 y) should read 12, 47, and 29 for the Current Study 2006–2008 Wetland 1, Wetland 2, and ORW Mean, respectively. The Current Study 2006–2008 Natural Wetland methane Emission (g CH4-C m −2 y) should read 57. Discussion P.789, L.50: “42 g CH4-C m −2 y” should read “29 g CH4-C m −2 y” P.790, L.33: “16 g CH4-C m −2 y” should read “7 g CH4-C m −2 y” The online version of the original article can be found at http:// dx.doi.org/10.1007/s13157-010-0038-6. A. M. Nahlik (*) :W. J. Mitsch Wilma H. Schiermeier Olentangy River Wetland Research Park, Environmental Science Graduate Program and School of Environment and Natural Resources, The Ohio State University, 352 W. Dodridge Street, Columbus, OH 43202, USA e-mail: nahlik.amanda@epa.gov W. J. Mitsch e-mail: mitsch.1@osu.edu Present Address: A. M. Nahlik U.S Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Western Ecology Division, 200 SW 35th Street, Corvallis, OR 97333, USA Wetlands (2011) 31:449–450 DOI 10.1007/s13157-011-0164-9