Ef. Wright et al., Regeneration from seed of six tree species in the interior cedar-hemlock forests of British Columbia as affected by substrate and canopy gap position, CAN J FORES, 28(9), 1998, pp. 1352-1364
Citations number
53
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
Canopy gap size can play a major role in determining composition of tree re
generation after disturbance. The effect of different positions within gaps
and within the intact forest has received less study. We seeded six tree s
pecies onto two substrates (organic and undisturbed moss) in three position
s along a north-south gradient within eight replicate 600-m(2) canopy gaps
and in the intact forest south of each gap (the gap positions), in 1995 and
1996. Emergence of all species was strongly affected by gap position, seed
bed substrate, and year, but there was little evidence of partitioning by g
ap position among the species. Average emergence was higher in the shady so
uthern position in gaps and within the intact forest and significantly high
er on organic than undisturbed moss substrates (with the exception of Abies
lasiocarpa (Hook.) Nutt., which showed no preference for seedbed). Seedlin
g survival was greatest for all species in the south end of the gap, where
soil moisture remained highest and light levels of approximately 20% full s
un were adequate for survival. A species trade-off was observed in the unde
rstory of the intact forest, where differential survival based on shade-tol
erance ranking occurred. To predict regeneration success in these forests,
for either silvicultural purposes or to permit a better understanding of co
mmunity dynamics and succession, it is important to consider the influence
of position inside and outside of gaps and the nature of the seedbed substr
ate.