Grantee Research Project Results
A Multi-Scale Examination Of The Spatio-Temporal Variations In Fire Regimes And Fire Climate Relationships Throughout The Central Range Of Whitebark Pine (Pinus Albicaulis)
EPA Grant Number: F5C20461Title: A Multi-Scale Examination Of The Spatio-Temporal Variations In Fire Regimes And Fire Climate Relationships Throughout The Central Range Of Whitebark Pine (Pinus Albicaulis)
Investigators: Larson, Evan R.
Institution: University of Minnesota
EPA Project Officer: Hahn, Intaek
Project Period: June 1, 2006 through May 1, 2008
Project Amount: $86,576
RFA: STAR Graduate Fellowships (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
Objective:
Whitebark pine (Pinus albicaulis) is a long-lived tree species that exists throughout high elevation forest communities of western North America. It is the foundation of an ecosystem that supports Clark’s nutcrackers, red squirrels, black bears, and grizzly bears. Whitebark pine facilitates the development of greater biodiversity in subalpine ecosystems and maintains the headwaters of many alpine watersheds throughout its range. The past 80 years have seen a dramatic decline in the whitebark pine ecosystem that is directly related to widespread mountain pine beetle outbreaks and infestations by the invasive white pine blister rust. This decline may be exacerbated by fire suppression and climate change. Efforts to restore whitebark pine ecosystems are increasing, but if management fails to slow current population trends, this species will become extinct from numerous regions over the next 15 - 20 yrs. Whitebark pine is a fire dependent species, and prescribed fire will be a critical tool in the management of this species. However, the broad distribution and wide environmental tolerance of whitebark pine creates many gaps in our knowledge of the fire ecology of this species. An urgent need exists to develop management strategies in accordance with the historical fire regimes of this keystone species.
My research objectives are to reconstruct and characterize the fire regimes of whitebark pine communities throughout the central range of the species, including previously unstudied regions in Montana, Idaho, and eastern Oregon. I will examine these data for spatial variations at local (inter-site variability) and regional scales (climate variability), and temporal variations to describe the historic range of variability for fire regimes of this system. I will also examine the fire-climate relationships in these forests at inter-annual (2 - 5 year) to multi-decadal (25 -100 year) scales, and describe the management implications of my findings.
Approach:
I will use dendroecological methods to reconstruct the fire history and age structure of whitebark pine forests throughout the central range of the species. I will collect data for 2 - 4 individual stands distributed within distinct watersheds that represent variation in slope, aspect, and topography. Multiple watersheds will be sampled within distinct regions to provide components at the site, cluster, and regional scales. I will use the fire history data to determine the potential use of the Poisson distribution in modeling fire activity, with potential benefits for developing ecologically-based fire management plans.
Expected Results:
My dissertation research will construct a framework of the historical range of variability in fire activity for the central distribution of whitebark pine and will provide an opportunity to examine long-term spatiotemporal trends in climate and fire activity in western North America. The long lifespan (1000+ years) of this species, with the addition of remnant wood, may provide fire history information on a millennial scale, at an annual resolution not attainable through other proxy-based paleoclimate investigations. I expect to find distinct differences in whitebark pine fire regimes at different scales and significant fire-climate relationships. The application of the Poisson distribution for modeling fire activity will incorporate the probabilities of fires occurring under specific climate and stand conditions, and may facilitate the timing and application of prescribed fire programs in whitebark pine forests. In addition to providing information on past fire regimes, high elevation ecosystems are highly sensitive to environmental change and I expect whitebark pine will be an excellent indicator of global climate change. My findings may indicate that climate, not 20th century fire suppression, is causing many of the modern changes in whitebark pine fire regimes.