Seed Bank Analysis Post Fuels-Reduction Treatments

Pinyon-Juniper (P-J) ecosystems are extensive throughout the western U.S. and have been expanding into shrublands and grasslands. A variety of tree-removal methods have been used in an attempt to restore herbaceous cover and reduce the risk of catastrophic fire with unknown effects on plant communities. I examined the impact of three different fuels reduction treatments on the local seed bank. The treatments were: mastication, where fuels are mulched and left in the plot; broadcast burn, where fuels are spread evenly across the plot and burned; and pile burn, where fuels are placed in discrete piles and burned. Treatments were adjacent to an untreated control site. The plot subjected to the pile burn treatment had a significantly higher seedling density (P = 0.04) than plot subjected to the broadcast burn treatment. Additionally, the plot subjected to the pile burn treatment had significantly higher species diversity (P = 0.0004) than the control. Artificial seeding, preformed by the Bureau of Land Management, had no effect on seedling density (P \u3e 0.05), but did significantly lower species diversity (P \u3c 0.0001). This study indicates that treatment, most notably the pile burn treatment, has an effect on seedling density and species diversity, while seeding nly affected species diversity