Fire on the New England landscape: regional and temporal variation, cultural and environmental controls

Aim We use a retrospective approach to reconstruct the past distribution of fire in New England and to investigate the important drivers of this pattern across the period of European arrival to North America. Location Our study sites are in New England, and range from pitch pine and oak forests of coastal Massachusetts, pine and hardwood forests of central Massachusetts, and northern hardwood and spruce fir forests of northern Massachusetts and Vermont. Methods We collected sediment profiles from eighteen lakes across the study area to assess fossil charcoal and pollen abundance over the past 1000 years, including the time period of European arrival and settlement. Results Based on presettlement pollen composition, our study sites are divided into three vegetation types: (1) pitch pine and oak, (2) oak, pine and hardwood and (3) northern hardwoods. The abundance of presettlement charcoal in these lakes is closely related to climate and the composition of surrounding vegetation. Charcoal is most abundant in pitch pine forests and least common in northern hardwood forests. Following the arrival of Europeans, charcoal abundance increased at most sites substantially, and vegetation composition changed in a direction of either greater dominance by pitch pine or white pine, depending on whether the forests were located in the southern or northern part of New England. Main conclusions The major factor influencing the distribution of fire across New England is climate, which has a direct effect on the physical conditions conducive to fire ignition and spread and an indirect effect on fire through its control on the distribution of vegetation at this spatial scale. We find evidence that other factors exert some control over local fire regimes as well including landforms and their impact on vegetation composition, firebreaks and prevailing winds. Native Americans likely influenced the local occurrence of fire, but their impact on regional fire regimes in New England is not apparent from this or other studies. However, additional palaeoecological, archaeological and historical work needs to be carried out to better address this question. In contrast, Europeans had a dramatic effect on fire throughout the New England landscape, increasing its occurrence almost everywhere.