Aboveground nutrient distribution within trees and stands in thinned and fertilized Douglas-fir

Abstract

The aboveground distribution of five elemental nutrients (N, P, K, Ca, Mg) among seven tree components was studied in Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) 9 years after thinning and urea fertilization at Shawnigan Lake, British Columbia. Thinning increased the concentration of N but decreased Mg within trees and increased the total gain in weight per hectare of all elements. Fertilization reduced the concentration of N, P, and K within trees after 9 years but increased the total weight per hectare of all elements except P. Each element was distributed heterogeneously among seven components of the trees.