Laboratory of Tree-Ring Research

Donald A. Falk

Adjunct Associate Professor, Dendrochronology

email: dafalk@ltrr.arizona.edu
   
office: 206 West Stadium
   
phone: 520.626.7201
   
mailing address:
Laboratory of Tree-Ring Research
105 West Stadium
University of Arizona
Tucson, AZ 85721
   
fax: 520.621.8229
   
interests: fire history, fire ecology, dendroecology, fire-climate relationships, disturbance interactions, ecological scale, restoration ecology, rare plant conservation



Don Falk: Research Interests

Don Falk’s work focuses on three general areas: fire regimes, disturbance interactions and fire-climate relationships, and restoration ecology. Most fieldwork is conducted in western North America, including ongoing programs in New Mexico and Arizona. New initiatives include fire history and fire-climate analysis in the North American Great Basin and the Sierra Madre of Mexico.
    One set of questions addressed in Falk’s lab revolves around the mathematical foundations of fire regime reconstruction and the development of analytical tools for fire history (Falk & Swetnam 2003, Falk 2004). A central case concerns the existence of scaling relationships in fire regimes, a problem noticed by a number of researchers but not previously studied systematically. We are also working on the development of probability models for surface fire regimes and mathematical theory for sample size analysis in fire history. This model, based on discrete set theory, applies to accumulating sets of experimental objects (such as fire-scarred trees) and provides a basis for the common practice of creating composite fire records in fire history research.
    A new project funded by the JFSP will link fire history, fire behavior, and land management practices in forest-grassland ecotones of the Valles Caldera National Preserve (VCNP), New Mexico. This project will attempt to reconstruct the ecotonal fire regime using remnant tree-ring evidence, and to infer spatial patterns of fire spread and climate regulation. In addition to the VCNP, the USGS Jemez Mountains Field Station is a central collaborator on this project.
    A second emerging area of interest is in fire-climate relationships. Collaborating with Dr. Swetnam, we use multivariate methods to understand persistent cross-scale patterns of synchrony in fire regimes of the western US. We are also taking preliminary steps for meta-analysis of fire history and climate relationships using distributed sampling designs that have been applied in a number of locations. Collaborators include Rocky Mountain Tree-Ring Research, the US Forest Service Fire Sciences Laboratory, Northern Arizona University, and others.
    In 2006 we initiated a program of fire history and climate work in the North American Great Basin, the largest area of the western United States lacking a basic network of fire history sites; the region is also located pivotally with respect to the “dipole” of the El Niño Southern Oscillation (ENSO) teleconnection in North America. We are beginning fieldwork in 2007; collaborators include the Bureau of Land Management and US Forest Service.
    The Falk lab collaborates with Dr. Ann Lynch, US Forest Service, Rocky Mountain Research Station (RMRS), to study disturbance interactions in the Pinaleño Mountains, Arizona. The Pinaleños are one of the highest “sky island” ranges, supporting high-elevation spruce-fir forests as well as extensive areas of mixed-conifer and other forest types. Our work combines reconstruction of historical fires, insect outbreaks, tree demography, and the role of climate variability in regulating short- and long-term forest dynamics.
    Restoration ecology is the third major area of focus in the Falk lab. A key project during this period was a book addressing the theoretical basis for the science of restoration ecology. Falk worked with colleagues Joy Zedler (University of Wisconsin), Margaret Palmer (University of Maryland), and more than 20 colleagues to assemble the first book on this subject. Foundations of Restoration Ecology was published by Island Press in 2006.
    In the field, the Falk group has been working on forest and fire regime restoration at the Monument Canyon, New Mexico site since 2003. We have established a plot-based program to study forest conditions, including annual monitoring of tree condition, understory diversity, and other variables. The project thinned approximately 230 ha in 2005-6, following a “process-centered restoration” model designed collaboratively with the Santa Fe National Forest (SFNF) (Falk 2006). We are also continuing a longitudinal study of old-tree responses to drought and competition in collaboration with the USGS Jemez Mountains Field Station, and a study of ecophysiological response of old trees to competition and release in collaboration with Los Alamos National Laboratory.
    A new restoration project linking forest thinning, fire behavior models, ecophysiology, and restoration of the fire regime is starting for the Sangre de Cristo Mountains, New Mexico. This project, also with the SFNF, will use strategically-placed thinning treatments (“SPLATS”) in heavily overgrown forest areas, followed by reintroduction of fire. Our lab’s role includes monitoring of treatment effects on old trees, as well as expanded fire history and post-treatment monitoring.

Dendroecology Workshop, 14 May -- 1 June 2007: Register now!


Curriculum vitae

Organizations doing important work in biodiversity conservation and ecological restoration:

Society for Ecological Restoration

Center for Plant Conservation




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