Refugia Sample Clauses

Refugia. On the IDF landscape there are few linear fuel breaks that would result in refugia areas where fire did not burn or burned on an extended cycle (Xxxxxxx et al. 2002). Areas with extensive wetland may have had some smaller fires, but there is potential for fires to spread around or across wetlands (Xxxxxxx et al. 2002). Fire extent was primarily determined by weather during the event, with some events being very large (Xxxxxxx et al. 2002). A type of refugia described by Xxxxxxx is the dry refugia where fuel is so discontinuous and sparse that fire would be exclude from those sites. Xxxxxxx et al. (2002) notes the dry refugia areas as steep south and west facing slopes. A second potential area of fire refugia from the frequent low severity fires is a portion of the study area known as the rock belt where surface rock percentages frequently exceed 50% surface cover (e.g. Enterprise 18 km, Alexis Creek south of the 4600 road). DWB staff have noted some areas where boulder rock surface cover is high enough that there is little to no surface ground fuels, particularly pine grass, available for consumption so these areas may also have offered areas of refugia from low severity surface fires. Xxxxxxx indicates their plots in the rock belt showed no difference in fire frequency (Pers. Comm. 2002). If rock belt areas were subject to less low severity fire there should have been a fuel buildup that resulted in presence of more higher severity fires and more even-aged structures. Even-aged structures have been noted associated with the rock belt areas (CP 113, Xxxx Xxxxxxx, pers. comm. 2003), but DWB staff has also noted numerous areas of uneven-aged Xxxxxxx-fir stands. DWB staff have also noted areas where pine dominated even-aged stands (likely caused by moderate and high severity fires) with little surface rock end abruptly where boulder rock covers the ground surface. In this case the stand in the boulder area was uneven-aged fir. This would seem to indicate that the boulder rock areas were less susceptible to these types of fires. The fact that boulder rock sites typically have less dense regeneration is likely due to the fact that there is not enough growing site to sustain a continuous layer of regeneration (Xxxxxxx pers. comm. 2003). This would mean that fuel buildup and ladder fuels in the absence of fire would not be as high for these areas. There is potential for rock belt areas to be fire refugia and that these areas would have a different stand structure...