HR: 0800h
AN: B41C-0642    [Abstracts]
TI: Forest type affects the influence of harvest on annual and cumulative litter decay in forest and wetland sites across Canada.
AU: * Trofymow, J A
EM: ttrofymow@pfc.forestry.ca
AF: Natural Resources, Canadian Forest Service, 506 Burnside Rd. W., Victoria, BC V8Z 1M5, Canada
AU: Thompson, E
AF: Environment Canada – Climate Research Br., 11 Innovation Blvd, Saskatoon, SK S7N 3H5, Canada
AU: Cameron, A
AF: Natural Resources, Canadian Forest Service, 1219 Queen Street E, Sault Ste. Marie, ON P6A 5M7, Canada
AU: Pare, D
AF: Ressources Naturelles, Service Canadien des Foręts, 1055 rue du P.E.P.S, Ste-Foy, QC G1V 4C7, Canada
AU: Lavigne, M
AF: Natural Resources, Canadian Forest Service, Regent St. S, Fredericton, NB E3B 7P7, Canada
AU: Flanagan, L
AF: Dept. Biological Sciences, Univ. Lethbridge, Lethbridge, AB T1K 3M4, Canada
AU: Moore, T
AF: Dept. Geography, McGill University, Montreal, QC H3A 2K6, Canada
AU: Amiro, B
AF: Dept. Soil Science, Univ. Manitoba, Winnipeg, MB V8Z 1M5, Canada
AU: Smyth, C
AF: Natural Resources, Canadian Forest Service, 506 Burnside Rd. W., Victoria, BC V8Z 1M5, Canada
AB: A litter decomposition study was established in 16 sites at 7 stations of the Fluxnet Canada Research Network. These sites included paired mature and clearcut forest sites at 5 upland stations (BC, SK, ON, QC, NB) as well as one site at each of two wetland stations (AW, QW) . All sites are instrumented for in situ measurements of soil moisture and temperature. Litterbags were prepared using one of four standard material types (aspen leaves - AL, black spruce needles BS, Douglas fir needles DF and birch wood sticks BW). Six replicate plots were located at each site, each plot contained sufficient numbers of surface litterbags of each material type to allow for four annual collections (2004 – 2007). As well unconfined birch chopsticks were placed at three depths down the soil profile (surface, 5cm, 15cm) and replaced annually to examine the effects of interannual variability on decay. Cumulative litter decay after three years litters rank by % mass remaining had AL<BS<DF<BW and most litters decay more rapidly in clearcut than forests, other than birchwood at one site (QC). Decay of surface birch sticks were similar and interannual variability was less than variability down the soil profile. The effects of clearcut varied with forest site type, on wetter sites surface BW decayed faster in clearcuts than closed forest, however this was reversed in drier forest site types. At lower soil depths on drier sites, decay was more rapid in clearcuts than closed forest. Work is continuing to relate insitu microclimates to decay rates.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0434 Data sets
DE: 0486 Soils/pedology (1865)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting