A study was carried out to investigate the effects of slash-burning on the nutrient status of two Sub-Boreal. Spruce zone ecosystems in the west central interior of British Columbia. The slash, forest floor and mineral soil (0—15 cm depth) in these ecosystems were sampled for mass and nutrient content before and. after burning on a recently clearcut site. The forest floor and mineral soil were also sampled for nutrient concentrations nine months following burning. Average losses of organic matter, N, P, S. K, Ca, and Mg to the atmosphere due to slashburning were 11.1 kg/m2 and 563, 55, 87, 60, 252, and 16 kg/ha, respectively, from the mesic ecosystems and 11.5 kg/m2 and 345, 52, 74, 16, 289, and 177 kg/ha, respectively, from the subhygric/hygric ecosystems. These amounts corresponded to 51, 47, 41, 56, 40, 40 and 20%, respectively, of the total quantities of these nutrients in the slash. and forest floor in the mesic ecosystems before burning, and 25, 9, 13, 14, 5, 6 and 17%, respectively, of the quantities in the subhygric/hygric ecosystems. There were substantial losses of organic matter from coarse (>8 cm diam.) and fine (Li cm diam.) slash and the forest floor components. However, nutrient losses were largely attributed, to fine slash and forest floor consumption. Nutrient losses from the fine slash ap~eared to be independent of fire severity, although losses of most nutrients from the forest floor increased with fire severity; in plots in the mesic ecosystems which received moderate impact burns, and plots in. the subhygric/hygric ecosystems which received low and. moderate impact burns, net gains in forest floor Mg, K, and K and Ca content.