In ponderosa pine (Pinus ponderosa Dougl. ex Laws.) forests of the western USA, fire exclusion by Euro-American settlers facilitated pine invasion of grass openings, increased forest floor detritus, and shifted the disturbance regime toward stand-replacing fires. We evaluated the impacts of two replicated ecological restoration treatments involving tree thinning alone (thinning restoration) and a combination of tree thinning, forest floor reduction, and prescribed burning (composite restoration) on soil microbial activity, biomass, and function approximately 8 yr after initial treatments. Microbial-N levels in the two restoration treatments were not significantly different from the control during either the dry or wet periods of the [...]
