Crown condition and nutrient status of red spruce (Picea rubens sarg.) in West Virginia

Abstract

The appearance, foliar nutrient status, and soil nutrient availability were determined for 9 trees in each of 39 red spruce stands in West Viginia. Visual evaluation of crown conditions for all 351 trees sampled resulted in median values of 5% for discoloration and 10% for defoliation. The most common symptom of discoloration was needle chlorosis, found on the upper surface of collected branches. Defoliation generally occurred beginning with the older year-classes of needles and progressed outward toward the branch tips. The levels of discoloration and defoliation varied to such an extent among stands, plots, and trees within a plot that a single causal agent was not likely responsible for the observed symptoms. Foliar nutrient levels were compared to observed crown condition but were inconclusive in proving a definite relationship between crown condition and any individual nutrient; levels of foliar N and P were negatively correlated to defoliation, but not to discoloration or live crown ratio; yet, foliar K was negatively correlated to both discoloration and defoliation and positively correlated to live crown ration. While individual sample trees exhibited symptoms of reduced health and vigor, the majority of red spruce sampled during the course of this study appeared healthy.