Collaborative Research: Legacies of Ojibwe Land Use in the Fire Regimes and Vegetation Communities of the Boundary Waters Canoe Area Wilderness

This collaborative research project will reconstruct fire histories across a network of sites in the Boundary Waters Canoe Area Wilderness in northern Minnesota in order to assess the potential impact of Native American land-use activities on fire regimes and vegetation patterns of the region. The project will advance basic knowledge about the extent and magnitude of human influence on landscapes often considered pristine and address the inclusion of humans as agents of change within ecological baselines of North American forests. The findings of this project should contribute to innovative thinking about the concept of wilderness as defined under the 1964 Wilderness Act. During the conduct of this project, research, education, and mentoring activities will be fully integrated to enhance undergraduate learning and prepare graduate students for future scientific careers. The investigators and collaborations built through the research will provide critical information to resource managers that will aid their long-term planning and management of wilderness landscapes.

The suppression of fires over the 20th century is one of the most visible and dramatic human impact on forest fires, leading directly to increasing tree densities and subsequent fuel-driven fire events that may be unprecedented over the last several centuries. The potential role of Native American burning on landscape structure and composition prior to the advent of effective fire suppression has received much less attention, however, but burning by the Ojibwe who lived in the study area and other Native Americans may have a substantial impact on present forest structure and composition. The use of fire by Native American groups to manipulate their surroundings may have augmented fire frequencies in many areas that are today considered relatively natural. If Native Americans historically augmented fire frequencies beyond the frequencies that would have occurred from lightning ignitions, vegetation patterns in areas that today are managed as natural areas might be a legacy of past human activity than previously had been realized. Understanding the relative impact of Native American fire use therefore is critically important as management agencies shift to active management strategies designed to mitigate external pressures, such as invasive species and climate change, through the application of disturbance processes like fire. To conduct this project, the investigators have worked with USDA Forest Service archaeologists to identify sites with known Ojibwe use alongside sites with little or no evidence of Ojibwe use. The researchers will use tree-rings to reconstruct past fire and forest demographic patterns at each site. They will compare the characteristics between each set of sites in terms of fire regime characteristics (fire frequency, fire synchrony, and fire-climate relationships) and vegetation patterns (forest age structure, composition, and canopy structure). Systematic differences in the fire history and vegetation patterns between the groups will provide quantitative evidence of the legacies of Ojibwe land use in contemporary forests, with direct implications for defining the concept and management of wilderness. Past fire history patterns also will be compared with modern records of fire and lightning to assess whether past fire history is similar to ignition or lightning strike density observed within the modern landscape.