Northeastern forests of the United States are currently acting as a carbon (C) sink following land abandonment in the early 1800s. Northeastern forests are also managed for a variety of purposes, including timber harvest, wildlife habitat, and ascetic value. There is widespread interest in management strategies that can maximize the carbon storing potential of forests as a tool to offset carbon emissions and mitigate climate change, while also supporting a diverse set of other objectives. The goal of this project is to assess the legacy of alternative management strategies on above ground biomass carbon sequestration in a central Adirondack forest with a long and documented history of timber harvest and management. This study utilizes continuous forest inventory (CFI) data collected from a 6000 hectare (15,000 acre) experimental forest over the last five decades. The CFI network consists of 288 plots in a systematic grid with 0.4 km (0.25 mile) spacing. Species, diameter at breast height (DBH), crown class, and vigor data was collected from every tree within a plot. Management was determined using historical records that describe silviculture treatments. Carbon density (Mg C ha-1) was estimated for each plot using biomass allometric equations and biomass/carbon fractions.
Results/Conclusions
High compartment-level variability in average carbon density indicate significant effects of management histories and intensities on carbon storage in distinct regions of the study site. The trajectories of aboveground forest carbon density of individual CFI plots were highly divergent, reflecting varying responses to management during the study period. This suggests that site and forest structure are likely to affect local responses to silviculture treatments. The site wide average carbon density in 1970 was 80.87 Mg C ha-1 (SE = 2.24) and dropped to 72.62 Mg C ha-1 (SE = 2.36) in 1981 following a series of shelterwood and clearcutting operations that affected ~1650 hectares (~4080 acres) of the study site. These operations extracted ~12 million board feet of timber from the property during that decade. Following these harvests, average carbon density increased at a rate of ~ 0.75 Mg C ha-1 year-1 to an average carbon density of 95.17 Mg C ha-1 (SE = 2.07) in 2011. These results indicate that aboveground live tree biomass carbon pools of northern hardwood and mixed-hardwood forests are resilient to timber harvest. This is consistent with studies that show other components of northeastern forests to be highly resilient to natural and anthropogenic disturbance.