Initial Understory Vegetation Response to Mechanical Mastication Fuel Treatments: Balancing Biodiversity and Fire Hazard Reduction

Ecologically sound fuels management actions are often desired, but ecological and fuels-based management goals may not be synchronous. The MAST treatment generated heavy loadings of woody fuel on the surface, which may inhibit the germination and establishment of shrubs, but also reduced richness of native understory species. Fuel treatments where the masticated material was partially removed by incorporation into the soil or prescribed burning, resulted in greater understory species establishment, but also resulted in higher abundance of fire-stimulated shrubs. The MAST/RX treatment removed the most fuel, but heat from the fire resulted in greater shrub density and higher levels of overstory tree mortality (Knapp and others, this proceedings). None of the mastication treatments investigated provide for an ecological and fuels management panacea. Instead evaluation of tradeoffs will be necessary to aid managers in determining the best management practices for ecosystem management in fire-prone environments.