Organic Matter and Nitrogen Distribution in Some Mountain Heath Communities of the Source Lake Basin, Washington

The soils and vegetation of subalpine mountain heath communities on colluvial, residual, and organic soils in the Source Lake basin of the west-central Cascade Range, Washington, were described and sampled for organic matter and nitrogen content in foliage, living stems, attached dead stems, roots, litter, and soil. Soil profile descriptions and vegetative cover data are presented. Total organic matter averaged 27.4, 39.3, and 100.2 kg m-2 and total nitrogen averaged 0.55. 1.09. and 1.71 kg m-2 in communities on the colluvial, residual, and organic soils, respectively. Live and attached dead vegetation contained 1.17, 0.74, and 2.38 kg m-2 organic matter and 8.9, 5.0, and 13.7 g m-2 nitrogen in the same communities on colluvial, residual, and organic soils, respectively. In all cases, the mass of live and attached dead vegetation constituted less than 5% of the total organic mass.