| Abstract
| - Dead-tree (snag) density (stems per hectare), diameter, species distribution and input rate were examined in Newfoundland boreal forests dominated by black spruce (Picea mariana (Mill.) B.S.P.) and balsam fir (Abies balsamea (L.) Mill.). Examinations were based on permanent sample plot data. Total snag densities were higher in fir than spruce and were densest in 40- to 59-year-old stands of both species. Densities of >9 cm diameter at breast height (d.b.h.; 1.3 m, hereafter all dimensions are dbh) snags and live trees and larger live and dead trees (>19 cm stems) were also higher in fir than spruce. Fir also generated more larger snags at a younger age than spruce. Precommercial thinning reduced snag densities, virtually eliminating >9 cm snags from 37- to 48-year-old forests. Disturbance regime had a minor impact on snag densities in >40-year-old forests. The annual rate of >9 cm snag production in >60-year-old forests was <1.6 and <1.2 per cent of live trees per year in fir and spruce, respectively. The annual rate of live >9 cm tree fall down in >60-year-old forests was <0.6 and <0.9 per cent in fir- and spruce-dominated forests, respectively.
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