The Forest Floor: Lateral Variability as Revealed by Systematic Sampling

The forest floor of a mature, naturally regenerated conifer stand on a well-drained podzolic soil in the Central Uplands of New Brunswick was sampled systematically. The forest-floor properties measured were: oven-dried mass per unit area, depth, moisture content, pH, potassium-chloride-extractable NH4-N and NO3-N, water-soluble phosphate, and ammonium-acetate-extractable K, Mg, and Ca. Total elemental C, N, P, K, Mg, Ca, Al, Fe concentrations were also determined. Coefficients of variation varied from 0.066 (total C) to 1.78 (2 N KCl-extractable NO3-N). Concentrations (measured in ppm or percent) were in each case less variable than absolute amounts (measured in kilograms per hectare). Frequency distributions were positively skewed (except for total C and N) and appeared to follow a gamma or Weibull distribution pattern.