HR: 1400h
AN: B13A-03    [Abstracts]
TI: Does Forest Management Affect The Structure Of The Soil Carbon Pool? Insights From A Long-Term Incubation Of Soils From A Managed Red Spruce Forest Chronosequence
AU: * Diochon, A
EM: adiochon@stfx.ca
AF: Environmental Sciences Research Centre, St. Francis Xavier University, Physical Sciences Complex PO Box 5000, Antigonish, NS B2G 2W5, Canada
AU: Kellman, L
EM: lkellman@stfx.ca
AF: Environmental Sciences Research Centre, St. Francis Xavier University, Physical Sciences Complex PO Box 5000, Antigonish, NS B2G 2W5, Canada
AB: Changes in the rate of microbial respiration throughout a long-term incubation of a soil have been used to empirically partition the soil carbon (C) pool into fractions. Using the rates at which the microbial community consumes each fraction, we can estimate turnover times and use these estimates to comment on a fraction's functional significance in the soil. An assumption of this approach is that the microbial community will consume the most labile fraction of the pool first. Since several studies have demonstrated that this pool of C is sensitive to management-induced changes in soil carbon cycling, long-term incubation of soils may be a useful technique for examining management-induced changes in soil C cycling. Using rates of respiration measured over a 526 d aerobic incubation conducted at 16 C, we present estimates of C fraction sizes and their turnover times for soils collected at six depths in the mineral soil from five managed red spruce forests representing ecologically significant stages of post-harvest regeneration. Our findings indicate that the structure of the C pool changes significantly on the timescale of ecological succession.
DE: 0400 BIOGEOSCIENCES
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0469 Nitrogen cycling
SC: Biogeosciences [B]
MN: 2009 Joint Assembly