Event Website

http://www.nafew2009.org/

Start Date

23-6-2009 4:40 PM

End Date

23-6-2009 5:00 PM

Description

We evaluated the applicability of mastication as a fuel treatment alternative within Northern Rocky Mountain moist and dry forests to treat post-harvest activity slash (moist forest) and standing trees (dry forest). On the moist forest site, we compared four different slash treatments, mastication, machine grapple piling, lop and scatter, and a control within a wildland urban interface setting to determine the effects of these treatments on soil nutrition, forest floor depth, and woody debris distributions. We randomly assigned the slash treatments and controls to 12 one-acre plots. Nitrogen, soil carbon, and magnesium concentrations within the soil components were not significantly different among the slash treatments. Lopped and scattered sites had significantly here duff depths than duff depths within the other slash treatments and control. Two years after treatment the structure and character of the masticated fuels was such that these areas resembled the grapple piled sites. We established the dry forest site to treat excess standing non-commercial 80-year old ponderosa pine. We masticated 20 acres in the fall; six one-acre plots were randomly located within the masticated area. We applied prescribed fire the following spring to three of the plots the remaining three plots were post-masticated controls. During the prescribed fire, flame lengths were low (< 0.5 m), although combustion continued to occur from smoldering. The radiation and convection was of sufficient intensity that crown scorching raised canopy base heights by 3 to 5 m. A critical element of the prescription was that lower duff moistures had to be greater than 100 percent during burning, therefore, there was little to no consumption of the forest floor even with the smoldering fire. Based on these results, we recommend that when burning masticated material particular attention to lower duff moisture is critical to minimize the down ward heat pulse.

 
Jun 23rd, 4:40 PM Jun 23rd, 5:00 PM

The Influence of Mastication on Soils and Fuels in Moist and Dry Forests of the Northern Rocky Mountains

We evaluated the applicability of mastication as a fuel treatment alternative within Northern Rocky Mountain moist and dry forests to treat post-harvest activity slash (moist forest) and standing trees (dry forest). On the moist forest site, we compared four different slash treatments, mastication, machine grapple piling, lop and scatter, and a control within a wildland urban interface setting to determine the effects of these treatments on soil nutrition, forest floor depth, and woody debris distributions. We randomly assigned the slash treatments and controls to 12 one-acre plots. Nitrogen, soil carbon, and magnesium concentrations within the soil components were not significantly different among the slash treatments. Lopped and scattered sites had significantly here duff depths than duff depths within the other slash treatments and control. Two years after treatment the structure and character of the masticated fuels was such that these areas resembled the grapple piled sites. We established the dry forest site to treat excess standing non-commercial 80-year old ponderosa pine. We masticated 20 acres in the fall; six one-acre plots were randomly located within the masticated area. We applied prescribed fire the following spring to three of the plots the remaining three plots were post-masticated controls. During the prescribed fire, flame lengths were low (< 0.5 m), although combustion continued to occur from smoldering. The radiation and convection was of sufficient intensity that crown scorching raised canopy base heights by 3 to 5 m. A critical element of the prescription was that lower duff moistures had to be greater than 100 percent during burning, therefore, there was little to no consumption of the forest floor even with the smoldering fire. Based on these results, we recommend that when burning masticated material particular attention to lower duff moisture is critical to minimize the down ward heat pulse.

http://digitalcommons.usu.edu/nafecology/sessions/mastication/5