Nutrient Accumulations in Jack Pine Stands on Deep and Shallow Soils over Bedrock

Abstract

Nutrient concentrations and distribution were studied in jack pine (Pinus banksiana Lamb.) stands on soils developed in shallow till (<30 cm) over three different bedrock types; granite, greenstone, and gabbro; and on soils developed in deep till (>1 m) in northeastern Minnesota. Plant nutrient concentrations varied among rock types, with plants on shallow soils over granite having low concentrations of Ca and Mg and plants on shallow soils over gabbro having low concentrations of P. Stands were separated into the following components: soil, forest floor, ground vegetation (mosses and lichens, herbs and low shrubs), tall shrubs, overstory boles, and overstory crowns. The distribution of nutrient mass paralleled the biomass of stand components. Stands on deep soils had more nutrients in every component, except ground vegetation, than did stands on shallow soils; and had more total nutrient mass. On shallow soils a larger proportion of total ecosystem nutrients was in the vegetation than on deeper soils. The removal of nutrients by timber harvesting may have more impact on nutrient status of stands growing on shallow soils than those on deep soils. Forest Sci. 26:325-333.