Engber, Eamon A.,  J.M. Varner, III, Leonel A. Arguello, and Neil G. Sugihara

A study conducted in the Bald Hills of Redwood National Park, California, USA, looked at the influence of overstory structure on fire intensity and fuels in oak dominated woodlands and savannas. Three sites that were prioritized for prescribed burns in 2008 and 2009 were the burn sites for the study. Site one had been burned five times since 1991, while sites two and three had been burned three times since then. It is important to note that grazing has also taken place on this land, sites one and two were grazed up until 1980, and site three was grazed until the year 1991, the year that particular site was added to Redwood National Park. Burn units were systematically split up into five categories of grassland, oak savanna, oak cluster, oak woodland, and invaded woodland based on their probable fuel structure and composition. Plots were then randomly selected for analysis. Fuels were sampled in four grades of leaf litter, woody material, combined live and dead herbaceous material, and shrub surface fuels.

Sampling of sites one and two were done in August of 2008, while sampling for site three was done in August of 2009. No sites were re-sampled. Prescribed burns were administered by Redwood National Park managers in the autumn of 2008. Sites one and two were burned in the autumn of 2008, however site three, which was scheduled to be burned in the autumn of 2009, could not be burned due to poor weather conditions.

Data needed for this study was behavioral because the forest ecologists were determining how encroachment of conifers affected the forest floor. This is just observing the tree’s behavior. Data was analyzed by running ANOVA tests on all of the different elements of the study. The largest differences in fuelbed were between grasslands and invaded woodlands, at opposite ends of the spectrum. Grasslands had heavier herbaceous mass and lower fuel moisture, while invaded woodlands were just the opposite. The invaded woodland sites had much more woody fuel, and lower herbaceous mass, resulting in lower community flammability. This suggests greater overstory shading and development of forest floors with denser woody material is somewhat responsible for less frequent fire.
Engber, Eamon A.,  J.M. Varner, III, Leonel A. Arguello, and Neil G. Sugihara. “The Effects of Conifer Encroachment and Overstory Structure on Fuels and Fire in an Oak Woodland Landscape.” Fire Ecology 7.2 (2011): 32-50. Agricola. Web. 22 Mar. 2017.