PHYSICAL-PROPERTIES OF DEAD AND DOWNED ROUND-WOOD FUELS IN THE BOREALFORESTS OF ALBERTA AND NORTHWEST-TERRITORIES

Dead and downed woody fuels in forests are commonly estimated using th e line intersect method, which requires appropriate values for specifi c gravity, piece tilt angle, and piece diameter. We present data for t hese variables for six commercially important tree species based on ex tensive surveys of slash and naturally fallen dead wood in four region s of the western Canadian boreal forest. The considerable variation by diameter size class, species, cover type, and, to a lesser extent, re gion suggests that specific values will improve fuel load estimates. W e combine the three variables into a single factor so that fuel load ( megagrams per hectare) can be simply calculated by multiplying this fa ctor by the number of intersects per metre of sample transect.