%0 Research article
%T Age and size structure of gap-dynamic, old-growth boreal forest stands in Newfoundland
%A McCarthy, John W.
%A Weetman, Gordon
%D 2006
%J Silva Fennica
%V 40
%N 2
%R doi:10.14214/sf.339
%U https://silvafennica.fi/article/339
%X The age and size structure of trees in old Abies-Picea-Betula forests on  Newfoundland’s Great Northern Peninsula were examined. It was  hypothesized that the size and age structure of both the tree and  regeneration “strata” of these stands display the complex structural  heterogeneity characteristic of classic, self-regenerating, uneven-aged  old-growth stands, and that the development and dynamics of such  structures occur over long periods of time. With all tree species  combined, dbh (diameter at breast height) and height distributions  exhibited a strong reverse-J character, with well-defined,  semi-logarithmic rotated sigmoid height and size frequencies. Seedling  height and basal diameter frequency distributions were reverse-J in  character. Live tree ages for all species, except white birch (Betula  papyrifera Marsh), ranged from 25 to 269 years, and were characterized  by all-age frequency distributions. Tree age and size were poorly  correlated. On average, balsam fir (Abies balsamea (L.) Mill.) required  62 years to reach breast height (1.3 m), with black spruce (Picea  mariana (Mill.) B.S.P.) and white spruce (Picea glauca (Moench) Voss)  requiring 40 and 48 years, respectively. Total age of dead standing  trees ranged from 45 to 232 years. Reverse-J age frequencies  characterized the seedling bank, with balsam fir seedlings present in  nearly all age classes up to 110, 120 and 85 years in three sample  stands. Seedling size (height and basal diameter)-age relationships were  characteristic of decades-long suppression. The combination of tree and  seedling bank size and age structure provide strong evidence of  quasi-equilibrium, small-scale, gap dynamic old-growth boreal forest  stands.