Denitrification Potential and Organic Matter as Affected by Vegetation Community, Wetland Age, and Plant Introduction in Created Wetlands
- Maria E. Hernandez * and
- William J. Mitsch
- Wilma H. Schiermeier Olentangy River Wetland Research Park, Environmental Science Graduate Program and School of Environment and Natural Resources, The Ohio State Univ., 352 W. Dodridge St., Columbus, OH 43202. M.E. Hernandez, current address: Environmental Biotechnology Unit, Institute of Ecology, Km 2.5 Carretera ant. a Coatepec 351, Congregación el Haya, AP 63, Xalapa 91070, Veracruz, México
Denitrification potential (DP) and organic matter (OM) in soils were compared in three different vegetation communities—emergent macrophyte, open water, and forested edge—in two 10-yr-old created riverine wetlands. Organic matter, cold water-extractable organic matter (CWEOM), anaerobic mineralizable carbon (AnMC), and DP varied significantly (P < 0.05) among vegetation communities. The surface (0 to 9 cm) soils in the emergent macrophyte community (EMC) showed highest DP (0.07 ± 0.01 mg N h−1 kg−1), OM (84.90 ± 5.60 g kg−1), CWEOM (1.12 ± 0.20 g kg−1), and AnMC (1.50 ± 0.10 mg C h−1 kg−1). In the deeper layer (9 to 18 cm), DP and CWEOM (0.04 ± 0.01 mg N h−1 kg−1 and 1.13 ± 0.20 g kg−1, respectively) were significantly higher in the open water community (OWC) than in the emergent macrophyte and forested edge communities. Plant introduction did not affect DP or OM content and characteristics. After 10 yr of wetland development, mean DP increased 25-fold in the surface layer (from 0.002 to 0.053 mg N h−1 kg−1); OM content more than doubled to 90.80 ± 19.22 g kg−1, and CWEOM and HWEOM increased 2.5 and 2.7 times respectively from 1993 (prewetland conditions) to 2004. Humic acids were the most abundant form of OM in 2004 and 1993 samples. Significant (P < 0.05) positive relationships between DP and OM, CWEOM, and AnMC were found in the surface layer; in the 9- to 18-cm layer, significant positive relationships were found between DP and CWEOM and AnMC.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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