Nutrient Cycling in Managed and Unmanaged Oak Woodland-Grass Ecosystems

Abstract

The influence of oak trees and grazing on nutrient cycling in oak woodland-grass ecosystems was examined at the Sierra Foothill Range Field Station in the northern-Sierra Nevada foothills of California. Nutrient concentrations in ecosystem waterflows (precipitation, canopy throughfall, and soil solutions) were monitored in a non-managed natural area and in an adjacent grazed area. Grazing increased soil solution concentrations of chloride (Cl) and sodium (Na), but had no effect on major nutrient levels. When comparing between oak and nonoak sites, the oak sites had enhanced soil solution concentrations of Ca, Mg, K, SO₄ and PO ₄, and decreased levels of Na. Soil solution pH beneath the oak canopy was 0.5-1.0 units greater than in adjacent grasslands, and appears to be due to neutralization of rainfall acidity by the oak canopy and enhanced base cation cycling by the oak.

Parent Publication

• Proceedings of the symposium on oak woodlands and hardwood rangeland management; October 31 - November 2, 1990; Davis, California

Citation

Dahlgren, Randy; Singer, Michael J. 1991. Nutrient Cycling in Managed and Unmanaged Oak Woodland-Grass Ecosystems. In: Standiford, Richard B., tech. coord. 1991. Proceedings of the symposium on oak woodlands and hardwood rangeland management; October 31 - November 2, 1990; Davis, California. Gen. Tech. Rep. PSW-GTR-126. Berkeley, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; p. 337-341