Tuesday, November 14, 2006

Soil organic carbon composition in boreal forests and peatlands.

Sylvie Quideau, 3-40C Dept. of Renewable Resources, University of Alberta, University of Alberta, Edmonton, AB T6G 2E3, CANADA, S.-W. Oh, Mokpo National University, Department of Chemistry, Muan, Chonnam 534-729, South Korea, and D. Paré, Service canadien des forêts, Centre de Foresterie des Laurentides, 1055, rue du PEPS , C.P. 3800, Sainte-Foy, QC G1V4C7, Canada.

The overall objective of this study is to examine the effects of climate, vegetation, natural (fire) and human-induced disturbance (harvesting) on soil chemical composition in boreal forest floors and peatlands as determined by solid-state CPMAS 13C NMR spectroscopy.  Analyses of samples from the Fluxnet-Canada research network, including 17 sites along an east-west national transect from New Brunswick to British Columbia were carried out using ramped-cross-polarization (RAMP-CP) on a Bruker Avance 400 spectrometer.  Integrated areas of spectral regions were ordered by non-metric multidimensional scaling (NMS).  Preliminary results indicate that samples clustered together by vegetation type regardless of their sampling location. Five to 35% of total soil carbon was mineralized during a one-year incubation at room temperature.  Analyses are underway to characterize the chemical composition of post-incubation samples.