Climate change and fire management in the mid-Atlantic region

Abstract

In this review, we summarize the potential impacts of climate change on wildfire activity in the mid-Atlantic region, and then consider how the beneficial uses of prescribed fire could conflict with mitigation needs for climate change, focusing on patters of carbon (C) sequestration by forests in the region. We use a synthesis of field studies, eddy flux tower measurements, and simulation studies to evaluate how the use of prescribed fire affects short- and long-term forest C dynamics. Climate change may create weather conditions more conducive to wildfire activity, but successional changes in forest composition, altered gap dynamics, reduced understory and forest floor fuels, and fire suppression will likely continue to limit wildfire occurrence and severity throughout the region. Prescribed burning is the only major viable option that land managers have for reducing hazardous fuels in a cost-effective manner, or ensuring the regeneration and maintenance of fire-dependent species. Field measurements and model simulations indicate that consumption of fine fuels on the forest floor and understory vegetation during most prescribed burns is equivalent to <1–3years of sequestered C, and depends on pre-burn fuel loading and burn intensity. Overstory tree mortality is typically low, and stands have somewhat reduced daytime C uptake during the next growing season following burns, but may also have reduced rates of ecosystem respiration. On an annual basis, net ecosystem productivity is negative the first year when consumption losses are included, but then positive in following years, and stands can reach C neutrality within <2–3years. Field data and model simulations suggest that increases in prescribed burning in fire-prone areas would have little appreciable effect on long-term forest C dynamics in some fire-prone forest types. Large-scale conversion to young pine plantations for fiber and biofuels will potentially increase the risk of wildfires, as had occurred previously in the late-19th and early-20th centuries in the region.