Document: GRE-3-33-6

Foliar nutrient contents and concentrations and their relation to stem volume growth in Pinus taeda L. and Pinus elliottii Engelm. stands of differing densities.

BARRON, G.A.*, R.E.WILL and R.O.TESKEY

University of Georgia, Athens, GA, USA ¹

Abstract:
As stand density increases, so does the demand for resources such as light, nutrients, and water. The objective of this study was to determine the relationship between canopy nutrient contents, concentrations, and stand growth for loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm.) pine stands. These stands, established in 1996, were planted at densities ranging between 741 and 4448 trees ha^-1. Total stem volume growth increased curvilinearly with increasing stand density. Overall, loblolly pine had significantly higher foliar concentrations of nitrogen and phosphorous than did slash pine. For loblolly pine, foliar nitrogen concentration decreased significantly from 1.31% to 1.02% as stand density increased. Foliar phosphorous concentration in trees growing at 741 trees ha^-1 was significantly higher than the 2224 and 4448 trees ha^-1 stands, but not than trees growing at 3706 trees ha^-1. For slash pine, foliar nitrogen concentrations decreased from 1.13% to 0.91% as stand density increased. Foliar phosphorous concentrations at these same densities also decreased as trees ha^-1 increased, but the decrease was not significant. Rather than being related to nutrient concentration, total stem volume growth was closely related to total nutrient content of the canopy, which was a function of nitrogen concentration and leaf area.

Keywords: Foliar nutrients, stem volume growth, stand density

This abstract is being presented at: 10:45 AM in session:
Oral Session #61: Plant Responses to Nutrients.