**2. Study area**

The study area is located west of Williams Lake in the Chilcotin plateau of interior British Columbia (52--53-N, 123--124-W) in the very dry and cold subzone of the Sub-Boreal Pine Spruce biogeoclimatic zone (SBPSxc). Average monthly temperatures range from -13.8-C in January to +11.6-C in July. The mean daily temperature is below 0oC from November to March. Average annual precipitation is 464 mm, of which 195 mm is snow. Soils are well drained brunisols and luvisols of sandy or sandy loam texture. Soil parent material is primarily glaciofluvial or morainal. The forest is relatively pure lodgepole pine with trembling aspen (*Populus tremuloides* Michx) in some of the newly disturbed stands. White spruce (*Picea glauca* (Moench) Voss) is the theoretical climax tree species over most of the SBPS. In the very dry and cold SBPSxc subzone area, however, the abundance of pine regeneration and the virtual absence of spruce regeneration on zonal sites suggests that lodgepole pine is the climatic climax tree species (Steen and Demarchi, 1991). Lodgepole pine grows relatively slow under such a dry and cold subzone. Average diameter and height are 17.8 cm and 14.4 m in mature stands, respectively.

Wildfire is a common, natural disturbance which cycles this type of forest about every 100 - 125 years (mean fire return interval in the SBPS Zone, J. Parminter, Ministry of Forests, Victoria, British Columbia). Other natural disturbance agents such as mountain pine beetles (*Dendroctonus ponderosae* Hopk) and dwarf mistletoe (*Arceuthobium americanum* Nutt) are common in the study area. The former can cause extensive tree mortality, and much of the harvesting in the study area was in stands where some (about 5-25%) of the dominant trees had been killed by mountain pine beetles. Dwarf mistletoe does not usually kill lodgepole pine but can cause severe losses of volume production.

There are two types of timber harvesting including stem-only harvesting (SOH) and wholetree harvesting (WTH) applied in lodgepole pine forests in the central interior of British Columbia. WTH removes most of the above-ground woody biomass including crown materials while SOH removes most of the above-ground woody biomass but leaves crown materials on the site. Concern has focused on the ecological impacts of the removal of nutrient-rich crown materials, and in WTH such removal may result in considerably more site nutrient depletion. For this study, we included both harvesting methods.
