Rocky Mountain Tree-Ring Research, Projects

Recent and Current Projects

Most of our research falls under the subdiscipline of dendroecology, the application of tree-ring data and methods to address ecological questions. Current projects mainly involve reconstructing forest and fire histories across vegetation, landscape, and regional gradients, and as affected by climate variability and changes in human land use. Recent studies include:

The overall goal of these studies is to provide a longer-term perspective on ecosystem patterns and processes, especially to assess where current conditions may be unsustainable and where management intervention - such as ecological restoration - may be needed. Evidence of past ecosystem conditions provides answers for the "what" and "why" of ecological restoration efforts: what do we restore to, and why is it important to do so? Knowledge of historical conditions provides not only guidance but - perhaps more importantly - justification for restoration efforts designed to return an altered or degraded ecosystem to some semblance of its longer-term ecological trajectory. Historical data provide what Aldo Leopold called a "base datum of normality" needed for informed natural resources management.

Other Studies:
Coast redwood: Several studies over the past 15+ years in coastal forests in California have found high fire frequencies in the form of long sequences of episodic fire scars (Brown and Swetnam 1994, Brown et al. 1999, Brown and Baxter 2003). These results were summarized in a recent paper that asked the question, "What was the role of fire in coast redwood forests?" (Brown 2007). While more data are needed from across the range of coast redwood, it is evident that surface fires were common and frequent in many historical forests and that these forests are not burning today anywhere near as often as they did in the past. The lack of fire also has led to associated changes in forest structure and feedbacks to the fire regime, with the result that current forests are likely more susceptible to stand-replacing crown fires that have the potential to affect much of the remaining old-growth coast redwood forest.

Movie of spatial patterns of fires at Cheesman Lake, Colorado (data from Brown, Kaufmann, and Shepperd 1999). The Cheesman landscape was completely burned over during the Hayman Fire in summer, 2002, and just about every tree for which we have age or fire-scar data was killed in the fire.