Monday, November 5, 2007 - 9:30 AM
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Annual Fluctuations of CO2, CH4 and N2O and Soil Properties in a Secondary Forest of Central Missouri.

Robert Paro, Lincoln University, 820 Chestnut St , Gis Lab (307) Founders Hall, Jefferson City, MO 65102-0029

Every year new accumulation of forest leaf litter and debris amass on the forest floor. These accumulations need to be broken down by various decomposers and this may have impact upon the emissions of greenhouse gases. The objective of this study was to assess the annual fluctuations in emissions of CO2, CH4 and N2O from a soil of a secondary forest and any relationships that may exist between these emissions and soil temperature (T), thermal conductivity (K), resistivity (R), and diffusivity (D). The study began in 2006 at Lincoln University Busby Forest. The forest geographic coordinates are 38o34’53”N and 92o08’07”W. It is dominated by Oak and Hickory trees on a Waldron Silty Clay (Aeric Fluvaquent) soil type. To collect soil air samples for analysis of CO2, CH4 and N2O, twenty static chambers of 0.30 m long and 0.20 m diameter were installed permanently on a 0.49 ha plot. These chambers were made from a PVC pipe and had two holes on sides with an open top. During sampling, the chambers holes and top were sealed for 30 minutes and air samples were collected and analyzed within two hours after collection using a GC-14A. Soil T, K, R, and D were directly measured inside the chamber using a KD2 probe. Results for 2006 sampling showed that CO2 fluxes ranged from 11.86 to 172.90 mg C-CO2 m-2 h-1, N2O from -5.72 to 18.80 ug N-N2O m-2 h-1 with CH4 uptake from -203.48 to -91.94 ug C-CH4 m-2 h-1. CO2 was linearly correlated with (K), (R), (T) and (D) whereas N2O only linearly correlated with (R). CH4 only correlated with (T). Correlation coefficients ranged from 0.40 to 0.60. Current data for sampling 2007 shows that greenhouse gases (CO2, CH4 and N2O) fluxes are following similar patterns as previously found in 2006.