Fuel succession in a western hemlock/Douglas-fir forest

Abstract

Fuel succession was quantified for a 515-year chronosequence in a Tsugaheterophylla/Pseudotsugamenziesii forest. Postfire stand ages selected were 1, 3, 19, 110, 181, and 515. After initial reductions due to mortality from fire in the first 3 years, live aboveground biomass in the tree component increased over time to over 1100 t/ha. Shrub and herb layer biomass was highest in year 19 and year 515. Dead aboveground biomass had different trends for different fuel size classes; normalized fuel loadings of five dead and down fuel categories peaked at four different stand ages: 1-h and 10-h timelag (TL) fuels, age 1; 100-h TL fuels, age 19; 1000-h TL fuels, age 110; >1000-h TL fuels, age 515. Surface fire behavior was highest early in the sere and lowest at ages 110–181. Old-growth forest patches appear to be best buffered against forest fire by mature forest patches rather than old growth or recently burned natural stands.

Decomposition and Mass of Woody Detritus in the Dry Tropical Forests of the Northeastern Yucatan Peninsula, Mexico

“…In the forests we studied, levels of woody detritus were increased 1.5-to 1.7-fold by hurricanes and 2.5-to 3.8-fold by fires. These increases are similar to those in a fire-killed PseudotsugalTmga forest in which woody detritus increased 2.7-fold (Agee & Huff 1987) and in a logged tropical forest in which woody detritus increased 3.4-fold (Uhl & Kauffman 1990).…”

“…Our estimates also fall within the amounts reported for total woody detritus in moister tropical forests, where 5-5 1 Mg/ha occur (Edwards & Grubb 1977, Kauffman et al 1988, Uhl & Kauffman 1990). In contrast, woody detrital mass in dry tropical forests is much smaller than in Pacific Northwest conifer forests, which range between 200 and 550 Mg/ha (Grier & Logan 1977, Agee & Huff 1987, Spies et al 1988. Thus, these comparisons suggest that there is no simple correlation between mass of woody detritus and latitude.…”

Lodgepole Pine and White Spruce Crown Fuel Weights Predicted from Diameter at Breast Height

“…This would enable managers to better forecast site preparation or planting costs due to knowledge of residue loadings. Also, this information may provide the forest manager with a better knowledge of how various natural and man-caused activities affect site productivity -by influencing debris build up, decomposition, and eventually, nutrient dynamics (Abbott and Crossley 1982, Agee and Huff 1987, Weber 1987. Information on how biomass changes by size class over time can also be used in predicting future fuel levels.…”

The impacts of forest management activities on carbon stocks and sequestration in the Aleza Lake Research Forest.

“…Much older low points of around 200 years were found in hemlock stands in Olympic National Park, Washington, USA, the dramatic 69 difference due to larger tree sizes taking significantly longer to decay (Agee and Huff 1987).…”

“…In northern forests, a general 'u '-shaped pattern of woody debris biomass or volume accumulation is often found along forest chronosequences (Lambert et al 1980;Agee and Huff 1987;Spies et al 1988). The 'u '-shaped pattern describes the relationship between the addition of new woody debris and the decay of existing woody debris.…”