NEAFWA 2018

AUTHORS: Michelle L. Brown, Vermont Cooperative Fish and Wildlife Research Unit, University of Vermont; Charles D. Canham, Lora Murphy - Cary Institute of Ecosystem Studies; Therese M. Donovan, U.S. Geological Survey, Vermont Cooperative Fish and Wildlife Research Unit, University of Vermont

ABSTRACT. Federal and state governments in the Northeast U.S. are actively engaged in assessing the potential role of forest biomass in meeting renewable energy goals. While current rates of timber harvest are generally sustainable, there is considerable pressure to increase the contribution of forest biomass for renewable energy. We estimated current harvest regimes for different forest types and regions across New York, Vermont, New Hampshire, and Maine using data from the Forest Inventory and Analysis Program. We implemented the harvest regimes in SORTIE-ND, an individual tree-based forest stand model, and simulated the effects of current harvest regimes and five additional harvest scenarios that varied by harvest frequency and intensity for 150 years. Forests were predicted to increase in adult aboveground biomass in all harvest scenarios in all forest type and region combinations, however, the magnitude of the growth varied dramatically (ranging between 3% and 120%). The variation in biomass growth can be largely explained by the disproportionately high harvest rates estimated for Maine as compared with the rest of the region. Despite steady biomass accumulation across the landscape, stands that exhibited older growth characteristics (defined as >=300 metric tons of biomass/hectare) were rare (8% or less of stands). Intensified harvest regimes had little effect on tree species composition, due to a predominance of partial harvesting that contributed to the prevalence of later successional species over time. Changes in forest structure, however, are known to affect wildlife distribution patterns. To test this, we developed expert-informed regional occupancy models for 12 forest bird species and predicted the impact of the various harvest regimes on the occupancy probability of each species. Our results suggest that forest biomass can represent a viable component of renewable energy policy in the Northeast, however, tradeoffs between biomass stock, supply, and wildlife distribution must be considered.