Effects of forest-floor disturbance on soil-solution nutrient composition in a black spruce ecosystem

Abstract

This study summarizes the effects of forest-floor disturbance on soil-solution chemistry. For comparative purposes chemical analyses are also presented of soil solution collected beneath undisturbed black spruce (Piceamariana (Mill.) B.S.P.) stands, stream water, and precipitation in the same area. The disturbance treatments were superimposed on the forest floor following removal of the black spruce overstory. These included burning of the forest floor, and mechanical removal of one-half and all of the forest floor. Conductivity, pH, and the concentrations of [Formula: see text], [Formula: see text], phosphates, K, Ca, and Mg were determined in the various water samples. Only in the case of the most severe treatments, one-half and all of the forest floor removed, was there substantial changes in conductivity, pH, and the concentrations of Ca and Mg. Potassium and P showed no consistent treatment effects. Lack of significant change in solution N concentration may reflect increased microbial activity and N immobilization in the forest floor in response to disturbance.