PARENT SESSION
Poster Session #18: Fire Ecology I.
Tuesday, August 6. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

The Interaction of climate, productivity, and decay rate on fuel loading in North American Forests.

Ryu, Soung-Ryoul^*,1, Chen, Jiquan¹, Crow, Thomas², Saunders, Sari³, Song, Bo⁴, Cleland, Dave⁵, Jurgensen, Martin³, ¹ University of Toledo, Toledo, OH² USDA Forest Service, Grand Rapids, MN³ Michigan Tech University, Houghton, MI⁴ Clemson University, Georgetown, SC⁵ USDA Forest Service, Rhinelander, WI

ABSTRACT- Fuel loading is a critical variable for predicting fire regimes. Using a generic model, we evaluated fuel loadings under various climate conditions, ecosystem productivity, and decay rates in 9 contrasting biomes along the longitudinal and latitudinal gradients in North America. Appropriate parameter values (i.e. decay rate) for each biome were adapted from the literature. Our initial simulations (400 years) under management (40 years rotation clearcutting) suggest that boreal, temperate, and tropical forests produce 6.01~42.31, 2.56~35.79, and 2.35~48.91 t/ha as fuel on the forest floor, respectively. Boreal forests had higher minimal values than temperate and tropical forests, which was due to low decay rates in the boreal forest rather than high productivity. We believe that the high minimal values for boreal forests are the primary reason for frequent forest fires. The maximum values for each biome reflect slash remaining after harvesting and the large maximal values for tropical forests suggest the necessity for careful harvesting strategies in tropical forests. Similar disturbance scenarios (e.g., harvesting frequency and intensity) produced significant differences among biomes. Sensitivity analysis of model parameters reveals that the decay rate of litter has the main impact on the maximal amount of fuel on the forest floor, while ecosystem productivity and the amount of litterfall are the key factors for determining average amounts of fuel. To continue this research, we will collect published data to examine the effect of productivity and decay rates on fuel loading across North America with using the generic model. We hypothesized that the main factor controlling fuel loading will be different along longitude, such as continental, Mediterranean (western coast), and marine (eastern coast) climates, and decay rates will be the most important factor along latitude.

KEY WORDS: fuel loading, decay rate, productivity