Changes in the understory of Canadian southern boreal forest after fire

Abstract

Abstract. We investigated changes in the composition and abundance of understory species after fire in the southern boreal forest around Lake Duparquet, Québec. Ten plots of 100 m2 were sampled in each of eight sites varying in post‐fire age from 26 to 230 yr, with 20 1‐m2 quadrats in each of these 80 plots. Variation in the understory was described by DCA ordination and interpreted as a regeneration succession series. Thickness of the organic layers, stand age and canopy composition were all correlated with vegetational change. This change was not constant throughout succession; some old sites showed an increase in the diversity and abundance of certain pioneer species. This was partly related to openings in the canopy resulting from a major outbreak of spruce budworm, which affected sites dominated by Abies balsamea. The ordinations were performed on both the 100‐m2 plots and the 1‐m2 quadrats. Heterogeneity within sites was larger at the 1‐m2 scale and there was a great deal of overlap in the position of the quadrats in ordination space. At the smaller scale of analysis, stand age and thickness of the organic layers were not correlated with the changes observed in the understory.

Le couvert végétal du Québec-Labrador il y a 6000 ans BP : essai

“…Dans l'ensemble des zones des Sapinières et des Érablières ( fig. 7), l'if du Canada (Taxus canadensis) a par ailleurs constitué des populations arbustives éminemment plus denses et étendues qu'actuellement entre 7000 et 4000 ans avant l'actuel, grossièrement à cheval, donc, sur l'époque des 6000 ans BP II est probable que des intervalles de feux très longs aient favorisé l'accroissement des populations de l'if (De Grandpré et al, 1993).…”

Post-fire succession on abandoned fields in coniferous forest habitat (Nord-East Poland)

“…Fire can consume extensive areas and totally destroy the tree stand (Bradshaw 1993;De Grandpre et al 1993;Engelmark 1993;Engelmark et al 1993). Many scientists ascertain that in the future, also in the temperate climate zone, there will be an increasing number of fire incidents due to changes in climate conditions, an increase in the frequency and intensity of extreme events, and a widening of the differences between wet and dry seasons.…”

Population structure and growth acclimation of mountain maple along a successional gradient in the southern boreal forest

“…mountain maple, Acer spicatum (Farrar, 1996). It grows well in a large range of habitats and persists through all stages of forest development (Post, 1965;Vincent, 1965;De Grandpré, Gagnon & Bergeron, 1993). Mountain maple generally develops as a single dominant stem that produces basal suckers with age or when damaged (Jobidon, 1995).…”