Bird community composition after mechanical mastication fuel treatments in southwest Oregon oak woodland and chaparral

To evaluate ecological effects of vegetation management in southwest Oregon oak woodlands and chaparral, we compared bird abundance and vegetation structure at four untreated stands and four stands where shrub cover had been reduced by using mechanical mastication thinning. Treated stands had less shrub cover than untreated stands. Three bird species were consistently more abundant on untreated stands. Species that were more abundant on untreated stands were associated with shrub cover, while those that tended to be more abundant on treated stands were associated with open areas, providing further evidence that the treatments were responsible for the observed differences in bird community composition. These results demonstrate a stronger response of shrub-associated species than was documented in an earlier study of smaller-scale shrub removal treatments. This difference suggests that managers can design treatment prescriptions that benefit particular species by altering the size and shape of project areas as well as the tools that are used to reduce shrub cover (e.g., mechanical vs. manual treatments).