117-4 A Regional Compilation of Sedimentary Charcoal Records from the White Mountains, NH: Initial results

Abstract:

As climate change and other anthropogenic activities increase wildfire risk across the United States, including the Northeast, a larger proportion of the population and ecosystems are projected to be impacted by large, damaging fires. As federal, state, local, and private forest stakeholders develop future best practices, including the use of fire as an ecosystem management tool, records of past fire occurrence, utilization, and impact are crucial in the development of forest management. To help provide this context, we present initial results from sedimentary charcoal records from 5 lakes and bogs in the White Mountains of New Hampshire covering the period of deglaciation at each site (~13-14 ka) to modern. Amongst all the cores, charcoal particle concentrations fluctuate but are persistent throughout each sediment record, indicating the consistent, though variable, presence of fire on the landscape. Thus far, several cores show higher, and more variable, charcoal concentrations immediately following deglaciation before decreasing to lower, less variable concentrations at ~7.5 ka. These lower concentrations persist through to modern, punctuated by discrete peaks; some of which are shared between cores. Separation and analysis of charcoal particles sizes (125-250, 250-500, >500µm) broadly show coherence within each record, although some peaks in the 125-250µm particle size are not mirrored in the larger grain sizes. These particle size relationships suggest that lake and bogs are generally capturing more local fire events, with periodic larger, farther afield events recorded across multiple records. Additionally, comparison of these charcoal records to tree-ring fire scar records from adjacent fire adapted tree stands will provide further insight into the preservation and interpretation of sedimentary charcoal. We continue to investigate chronological issues related to bog sedimentation and interpretation of charcoal peaks given the limits of our sampling resolution (~20-70 yr cm^-1). Forthcoming pollen assemblage analyses will add to these results and provide ecological trends, relationships, and responses to fire regimes. The finished sedimentary charcoal records, tree-ring fire scar histories, and pollen analyses will provide important context for the development of forest best management practices under projected climate and ecological changes.

Geological Society of America Abstracts with Programs. Vol. 58, No. 5, 2026

doi: 10.1130/abs/2026AM-18673

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