TREES Lab personnel are conducting research across the United States and around the world. Below are short descriptions of several of our current projects and a list of other active areas of research in the TREES Lab. Please contact us if you want to learn more about any of these areas of research.
In 1964 the United States Wilderness Act defined wilderness as “an area where the earth and community of life are untrammeled by man, where man himself is a visitor who does not remain.” This definition has guided management decisions pertaining to some of the most spectacular landscapes in North America yet is based on an incomplete and potentially problematic ignorance of the long-term legacies of past cultural and land-use practices that resonate in vegetation communities to this day. This project will reconstruct the fire history of a network of sites across the Boundary Waters Canoe Area Wilderness (BWCAW) of northern Minnesota to assess the potential impacts of Ojibwe land use on the historical fire regimes and modern vegetation patterns of the study area. This research will update and increase the spatial and temporal resolution of the ground-breaking fire history research conducted in the BWCAW by Miron ‘Bud’ Heinselman in the 1960s and 1970s. The results of this work will advance the debate over the extent and magnitude of human influences on landscapes that are often considered pristine or natural, address the important question of the meaning and usefulness of the concept of an ecological baseline in the management of North American forest systems, and advance innovative thinking around the concept of wilderness in order to help transform the ecological basis and implications of wilderness management as defined under the 1964 Wilderness Act.
This project was funded by the National Science Foundation.
Since the last Ice Age, shoreline elevations of the Great Lakes were influenced by post-glacial isostatic rebound, changing outlet elevation, and climate change. The Dune Undergraduate Geomorphology and Geochronology (DUGG) project focuses on how these processes influence eolian systems along the Wisconsin shoreline of Lake Michigan. Unlike the eastern side of the Lake, large dunes are rare along the Wisconsin shoreline except for a few areas of the Door Peninsula. Students from across the country work with Dr. Rawling and colleagues from the University of Nebraska-Lincoln and the UW-Extension Wisconsin Geological and Natural History Survey for eight weeks during the summer. Methods employed for this student-driven undergraduate research includes ground penetrating radar, optical dating and laser diffraction particle-size analysis. The DUGG project is funded by National Science Foundation Research Experience for Undergraduate program.
Hear more about DUGG in a broadcast by Jeff Strobel on Madison's WORT 89.9 FM.
This project was funded by the National Science Foundation.
Reconstructing Climate from Ancient Whitebark Pine and Limber Pine in the Eagle Cap Wilderness, Oregon
The global climate system varies at all scales of space and time, and only by understanding the past can we develop a better understanding of how climate may change in the future. This project is focused on developing long tree-ring chronologies from whitebark pine and limber pine growing at high elevations in the rugged Eagle Cap Wilderness of eastern Oregon to explore past climate variations in this region. Thus far a 900-year limber pine chronology and a 1,100-year whitebark pine chronology have been developed. Additional sampling is planned in the near future.
In the summer of 2009, Dr. Larson helped film a documentary about one tree in particular; Dielman’s Monarch, an ancient limber pine growing on the slopes of Cusick Mountain, has likely been growing on that spot for over 2,000 years. You can watch the 10 minute film online.
This project has grown out of previous projects funded in part by the National Science Foundation, the United States Environmental Protection Agency.
If you have used an earthworm for fishing bait, picked a worm out of your garden, or noticed a worm crawling across a sidewalk after it rains you have been in the presence of an invasive species. The Great Lakes Region has no native earthworm species as a result of the last Ice Age, during which much of the region was hidden beneath up to a mile of ice and the rest was frozen in permafrost. The earthworms that are now nearly ubiquitous in the Great Lakes Region are of European origin and have followed in the wake of European settlement and agriculture. Known to be beneficial in agricultural ecosystems, it has only recently been realized that the invasions of European earthworms into previously worm-free hardwood forests of the Great Lakes are profoundly influencing nutrient cycles, understory plant diversity, and the patterns of spread among invasive plant species. This project is investigating the effects of invasive earthworms on overstory forest dynamics, through the proxy of tree rings, with potential implications for the forest managers throughout the Great Lakes Region.
This research has been funded by the Wisconsin Louise Stokes Alliance for Minority Participation.
The structure and composition of forests around the world are changing in rapid and unprecedented ways. Human activities, such as logging and expansion of the urban-wildland interface, have resulted in highly fragmented landscapes in areas that were once covered with relatively continuous tracts of forest. The close links between landscape structure, disturbance regimes, and successional processes suggest that modern fragmented landscapes are likely operating outside of their historical ranges of variability, yet the long time scales on which the dynamics of forest communities operate make this difficult to assess. Additionally, landscape structure, legacy effects, and seed source availability and proximity also represent important determinants of vegetation change. Understanding how forest communities will change in the future is key information needed in the development of long-term management plans for these ecologically and economically critical systems. This project is using the naturally fragmented landscape of Granlandet Reserve in northern Sweden as an analog to explore the long-term and unintended consequences of changing landscape structure.
This research was funded by a J. William Fulbright award and by Mid Sweden University.
The White River Badlands of South Dakota have some of the fasted documented modern erosion rates in North America that result in characteristically rugged terrain. These processes are also responsible for vast exposures of Quaternary sediment that provide an opportunity to investigate the long-term evolution of these common arid and semi-arid landscapes. Dr. Rawling’s projects here have focused on eolian systems including cliff-top deposits, sand dunes and loess. These deposits have been intermittently active throughout the last 15,000 years and are dated with radiocarbon and optical age estimates. The White River Badlands were also significant dust sources in the Pleistocene, and the focus of current research is investigating the genesis of dust there.
This research was funded by the American Chemical Society Petroleum Research Fund.
In addition to these projects, other active research in the TREES Lab includes:
- Updating existing tree-ring chronologies in Maine, Wisconsin, and the Upper Midwest
- Developing long tree-ring chronologies from moisture-sensitive piñon pine trees growing in the white mountains of California
- Extending existing longleaf pine chronologies from central and north-central Florida into the 1600s to gain insight into past hydroclimate variability
- Analyzing climate change impacts on forest development and productivity at Arctic treeline in northern Manitoba
- Reconstructing larch sawfly outbreaks using tamarack tree rings in the Boundary Waters Canoe Area Wilderness
- Examining the spatial and temporal dynamics of fire in Jämtgaveln Reserve in central Sweden
- Developing long chronologies and precipitation reconstructions from Scots pine growing on the bluffs above the Baltic Sea in Skuleskogen National Park, Sweden