A comparison of pre-European settlement (1857) and current (1981-1995) forest composition in central Ontario

Abstract

Presettlement forest composition along a 278 km long transect through central Ontario was recreated from Ontario land survey notes (1857) and compared with existing forest composition as derived from Forest Resource Inventories (1981-1995). Trends through time were analyzed by means of detrended correspondence analysis and univariate statistics (paired t tests and Wilcoxon matched-pair signed-ranks tests). Ordinations based on the first tree taxon listed in a stand and on all tree taxa provided similar results. The eastern half of the transect was initially dominated by boreal conifers, whereas the western half supported stands typical of Ontario's Great Lakes - St. Lawrence (GLSL) region. Significant reductions of yellow birch (Betula alleghaniensis Britt.), balsam fir (Abies balsamea (L.) Mill.), and eastern white cedar (Thuja occidentalis L.) and significant increases of poplar (Populus spp.) and white birch (Betula papyrifera Marsh.) were observed within the boreal half. A significant reduction in eastern white cedar and an increase poplar were observed in the western half. Changes in the boreal region strongly support previous studies conducted over shorter time periods and may be attributed to clear-cut harvesting. The persistence of shade-tolerant hardwoods within the GLSL region can be attributed to the prevalence of small-scale disturbances associated with partial-cut harvesting systems.

Effects of natural resource development on the terrestrial biodiversity of Canadian boreal forests

“…Root damage and exposure during harvesting often results in post-logging decline and mortality of larger residual white birch within a few years (Farrar 1995). Post-disturbance regeneration may be higher following wildfire than harvesting (Nguyen-Xuan et al 2000;Simon and Schwab 2005;Ilisson and Chen 2009b;Boan et al 2011), depending on the degree of forest floor disturbance (i.e., seedbed availability) (Harvey and Bergeron 1989) and, for harvested stands, vegetation control Belle-Isle and Kneeshaw 2007) but see Jackson et al (2000) and Pinto et al (2008).…”

Cover type, environmental characteristics, and conservation of terrestrial gastropod diversity in boreal mixedwood forests

“…Canadian boreal mixedwood forests are increasingly being managed in ways that favor large stands of tree monocultures rather than the natural mosaic of smaller scale mixedwood patches (Hobson and Bayne 2000;Jackson et al 2000;Lieffers et al 2008). If forest management aims to re-establish preharvest forest conditions following harvest, maintaining a variable tree species mixture that includes fine-grained mixes of both broadleaved and coniferous trees may best ensure broad-scale persistence of forest flora and fauna in more natural patterns, including forestdwelling gastropods in the boreal mixedwood.…”

“…This is particularly true because present management systems for boreal mixedwood forests tend to favor large stands of homogeneous composition rather than the mosaic of smaller scale patches of varying broadleaf-conifer dominance that characterizes many unmanaged mixedwood stands (Hobson and Bayne 2000;Jackson et al 2000;Lieffers et al 2008). In this paper, we describe gastropod distribution patterns in mature, unmanaged mixedwood stands in northern Alberta.…”

Anthropogenic Disturbances Create a New Vegetation Toposequence in the Gatineau River Valley, Quebec

“…For example, "plaine" (n = 1) and "soft maple" (n = 9) were associated to red maple and consequently to maple, "épinette rouge" (n = 3) to tamarack, and "black birch" (n = 16) to yellow birch. Taxa were apparently noted from the most important to the least important, as suggested by many authors [39][40][41] and statistically demonstrated by Terrail et al [42]. Position on the list was transformed into a measure of abundance following the broken-stick model [43].…”

“…The "Pine" forest type, which was the most common during the preindustrial period, is rare today and confined to thin or coarse-textured deposits. Pine has decreased similarly in many other regions of northeastern North America [5,8,13,14,[17][18][19]24,39,[49][50][51][52][53][54]. Several factors may be responsible for the decrease in pine.…”