Competitive interactions between juvenile trembling aspen and lodgepole pine: A comparison of two interior British Columbia ecosystems

Birch (Betula papyrifera) × white spruce (Picea glauca) interactions in mixedwood stands: implications for management

“…Moreover Mitchell (2003) and Newsome et al (2010) reported that diameter is an excellent response variable for competition studies because interspecific competition affects diameter growth more than it affects height growth. In many investigations (DeLong 1991;Simard et al 2001;Newsome et al 2008) it was reported that diameter responds more quickly than height to external sources whereas height responses tend not to be expressed until conifers are experiencing extreme stress and low vigour. The most appropriate functional forms between the response variables and each competition index were identified according to .…”

Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

“…This strategy ignored the important role that trembling aspen plays in forest health (e.g., [3,4]) and landscape-level development [5][6][7]. In recent years, efforts have been made to identify competition indices and ecosystem-specific thresholds that would increase the retention of trembling aspen in juvenile stands [8][9][10]. Some progress has been made.…”

“…Some progress has been made. We now know that within a relatively small geographic range in south-central British Columbia, aspen has greater ability to intercept light and to compete with neighbouring lodgepole pine in productive Sub-Boreal Spruce (SBS) ecological units than in the drier, less productive Interior Douglas-fir (IDF), and the even drier and colder Sub-Boreal Pine Spruce (SBPS) units [9][10][11][12]. However, competitive interactions have been highly variable between sites even within the same ecological unit, which Filipescu and Comeau [13] also observed for trembling aspen-white spruce (Picea glauca (Moench) Voss) interactions.…”

“…Until now, studies in south-central British Columbia have focused on lodgepole pine responses to neighbouring trembling aspen of equal or greater height [9,10]. Less effort has been put into characterizing competitor aspen and their size relationships with lodgepole pine in different ecological units.…”

“…The original studies examined and reported on aspen-lodgepole pine competitive relationships. Competition thresholds based on aspen density were identified, where competitors were defined as aspen that were as tall or taller than target pine [9,10]. The present study makes use of the same data sets, plus additional information collected in 2008 and 2009 at two of the sites, to more precisely characterize the most important competitor aspen.…”