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Abstract. Logging is a larger cause of adult tree mortality in northeastern U.S. forests than all other causes of mortality combined. We used Forest Inventory and Analysis (FIA) data to develop statistical models to quantify three different aspects of aggregate regional forest harvest regimes: (1) the annual probability that a plot is logged, as a function of total aboveground tree biomass, (2) the fraction of adult tree basal area removed if a plot was logged, and (3) the probability that an individual tree within a plot was removed, as a function of the fraction of basal area removed at the plot level, the species of tree, and its size. Results confirm that relatively frequent partial harvesting dominates the logging regimes, but with significant variation among different parts of the region and different forest types. The harvest regimes have similarities with natural disturbance regimes in imposing spatially and temporally dynamic mortality that varies predictably as a function of stand structure as well as tree species and size.

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Short-rotation woody crops like shrub willow are a potential source of biomass for energy generation and bioproducts. However, since willow crops are not widely grown in North America, the economics of this crop and the impacts of key crop production and management components are not well understood. We developed a budget model, EcoWillow v1.4 (Beta), that allows users to analyze the entire production-chain for willow systems from the establishment to the delivery of wood chips to the end-user. EcoWillow was used to analyze how yield, crop management options, land rent, fuel, labor, and other costs influence the Internal Rate of Return (IRR) of willow crop systems in upstate New York. We further identified cost variables with the greatest potential for reducing production and transport costs of willow biomass. Productivity of 12 oven-dried tons (odt) ha −1 year −1 and a biomass price of $ (US dollars) 60 odt −1 results in an IRR of 5.5%. Establishment, harvesting, and transportation operations account for 71% of total costs. Increases in willow yield, rotation length, and truck capacity as well as a reduction in harvester down time, land costs, planting material costs, and planting densities can improve the profitability of the system. Results indicate that planting speed and fuel and labor costs have a minimal effect on the profitability of willow biomass crops. To improve profitability, efforts should concentrate on (1) reducing planting stock costs, (2) increasing yields, (3) optimizing harvesting operations, and (4) co-development of plantation designs with new highyielding clones to reduce planting density.

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Forest carbon cycles play an important role in efforts to understand and mitigate climate change. Large amounts of carbon (C) are stored in deep mineral forest soils, but are often not considered in accounting for global C fluxes because mineral soil C is commonly thought to be relatively stable. We explore C fluxes associated with forest management practices by examining existing data on forest C fluxes in the northeastern US. Our findings demonstrate that mineral soil C can play an important role in C emissions, especially when considering intensive forest management practices. Such practices are known to cause a high aboveground C flux to the atmosphere, but there is evidence that they can also promote comparably high and long-term belowground C fluxes. If these additional fluxes are widespread in forests, recommendations for increased reliance on forest biomass may need to be reevaluated. Furthermore, existing protocols for the monitoring of forest C often ignore mineral soil C due to lack of data. Forest C analyses will be incomplete until this problem is resolved.