Estimating total soil mass, nutrient content, and trace metals in soils under a low elevation spruce-fir forest

The concentration, contents, and distribution of nutrients, metals, and soil materials were quantified at the Howland Integrated Forest Study (HIFS) site in eastern Maine. The site is a mature, low-elevation spruce-fir forest on Podzolic soils developed from dense basal till. Standard morphologically based soil sampling and quantitative soil pits were both used to characterize the soil component of this ecosystem. Vertical trends in nutrient concentrations at the site were largely governed by the distribution of organic matter. Standard morphological soil sampling techniques tended to overestimate soil pools of labile cationic nutrients and C, and underestimate trace metals and P, as a result of underestimations of coarse fragment content. These discrepancies can be critical if extrapolations for nutrients, metals, and C are made using existing databases to regional or global scales.Key words: Forest soils, spruce-fir, quantitative pits, sample size