Conifer regeneration Sample Clauses

Conifer regeneration. Xxxxxxx et al. (2002) found that historical regeneration densities could not be determined as smaller stems did not persist on the forest floor for extended periods and therefore have left no trace from historical times. Some envision historic IDF Xxxxxxx-fir forests as being open and park like, with little if any regeneration. Others contest this idea. Results from recent grass-land burning in the Chilcotin show high fire survival rates of Xxxxxxx-fir regeneration 1 to 1.5m in height, suggesting Xxxxxxx-fir regeneration may have survived low severity events (X. Xxxxx, Pers. Comm. 2003). Xxxxxxx suggests that this Xxxxxxx-fir regeneration was quite old and had short height due to the severity of the growing site. This older regeneration would have developed thicker bark and been more able to withstand the effects of fire than younger regeneration (Pers. Comm. 2003). Another consideration is that grassland and understory thickets are different sites. In the more open grassland heat from the fire would be more dissipated than under a continuous canopy. The trapped heat in the timbered stand would be more likely to cause mortality (Xxxxx Xxxxxxx, Per. Comm. 2003). Sampled old Xxxxxxx-fir trees indicate that when they were saplings they grew at a much faster rate than current understory saplings, indicating that historical densities were much less than they currently are (X. Xxxxx, Pers. Comm. 2003). The general consensus is that there was significantly less dense regeneration and poles in historic Xxxxxxx-fir stands than there is today, but there is no data available to set any numerical targets. Observation from burning trials may be able to provide this data and growth and yield modeling may shed further light. In frost prone areas Xxxxxxx-fir has difficulty establishing in the absence of an overstory. In the current fire excluded landscape dense layers of Xxxxxxx-fir have established under pine stands. In the past this regeneration would likely have been restricted to ridges or frost draining slopes (Xxxxxxx et al. 2002) Low severity fires have a tendency to burn in a patchy distribution so it is likely that regeneration was spatially distributed in patches (X. Xxxxx, Pers. Comm. 2003) and that these patches would have ranged from single stems to small dense patches (Xxxxxxx Pers. Comm. 2003). Xxxx and XxXxxx (1998) estimated that thickets of regeneration likely covered about 5% of the area in their historic target stand in the IDFdm2 located in the east K...