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Quantifying Carbon Dioxide and Methane Emissions and Carbon Dynamics from Flooded Boreal Forest Soil
Author(s) -
Oelbermann Maren,
Schiff Sherry L.
Publication year - 2008
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2008.0027
Subject(s) - environmental chemistry , delta , carbon dioxide , environmental science , soil carbon , podzol , fractionation , taiga , methane , greenhouse gas , chemistry , soil horizon , soil water , soil science , ecology , organic chemistry , biology , engineering , aerospace engineering
The boreal forest is subject to natural and anthropogenic disturbances, but the production of greenhouse gases as a result of flooding for hydroelectric power generation has received little attention. It was hypothesized that flooded soil would result in greater CO 2 and CH 4 emissions and carbon (C) fractionation compared with non‐flooded soil. To evaluate this hypothesis, soil C and nitrogen (N) dynamics, CO 2 and CH 4 mean production rates, and 13 C fractionation in laboratory incubations at 14 and 21°C under non‐flooded and flooded conditions and its effect on labile and recalcitrant C sources were determined. A ferro‐humic Podzol was collected at three different sites at the Experimental Lakes Area, Canada, with a high (19,834 g C m −2 ), medium (18,066 g C m −2 ), and low (11,060 g C m −2 ) soil organic C (SOC) stock. Soil organic C and total N stocks (g m −2 ) and concentrations (g kg −1 ) were significantly different ( p < 0.05) among soil horizons within each of the three sites. Stable isotope analysis showed a significant enrichment in δ 13 C and δ 15 N with depth and an enrichment in δ 13 C and δ 15 N with decreasing SOC and N concentration. The mean CO 2 and CH 4 production rates were greatest in soil horizons with the highest SOC stock and were significantly higher at 21°C and in flooded treatments. The δ 13 C of the evolved CO 2 (δ 13 C‐CO 2 ) became significantly enriched with time during decomposition, and the greatest degree of fractionation occurred in the organic Litter, Fungal, and Humic forest soil horizons and in soil with a high SOC stock compared with the mineral horizon and soil with a lower SOC stock. The δ 13 C‐CO 2 was significantly depleted in flooded treatments compared with non‐flooded treatments.