Nitrogen Concentrations in the Current Foliage and in Fresh Litter of Fertilized Black Spruce Stands

Abstract

In three separate fertilization experiments in black spruce stands, the concentration of nitrogen in foliage collected from the trees and the needles of litter samples gathered from screens on the soil surface were closely correlated. Nitrogen concentrations in litter samples collected in October were more closely correlated with nitrogen level in the trees at that time of year than the litter samples gathered in May. Nitrogen in the twigs was weakly correlated with foliar nitrogen status. Nitrogen concentrations in litter samples collected in May were highly correlated with the foliar nitrogen measured during the previous year. The coefficient of correlation differed between the stands. Regression coefficients were not time-stable in all the stands.