Event Title

Aspen fire ecology and climate change: Disturbance dynamics in an uncertain future

Presenter Information

Doug Shinneman

Location

USU Eccles Conference Center

Event Website

www.restoringthewest.org

Abstract

Aspen is the only deciduous tree species with substantial extent across much of the western United States, and decline of aspen woodlands due to climate change would likely alter ecological processes and result in cascading losses of animal and plant species in the region. Recent aspen mortality events in the western U.S. might be harbingers of future aspen disturbance dynamics under climate change, and some climate-based vegetation models suggest substantial loss of aspen over the next several decades. However, the role of future disturbance, particularly fire, complicates our ability to predict aspen distribution and productivity under climate change. Aspen is typically seral to conifer tree species, re-sprouts prolifically after fire and, thus, is often considered to be a fire-dependent species. However, some aspen populations may be stable in the absence of fire, and a recent review suggests at least five aspen fire regime types are possible. Thus, although hotter and drought-prone future climates may increase aspen mortality in some locations (e.g., at lower elevations), these same climate conditions are also predicted to increase wildfire activity across much of the western United States, and this could be beneficial to aspen in other locations (e.g., at higher elevations where conifers now dominate). Here, I present an overview of aspen-fire dynamics in the western U.S., including describing different aspen fire regimes, and discussing how future climate-fire interactions might affect aspen populations. I also present preliminary modeling results as a case study for potential changes in aspen distribution and abundance under alternative future climate scenarios and fire regimes in the northern Great Basin. I then discuss the relevance of this research to aspen restoration efforts, highlight key areas of scientific uncertainty, and suggest high-priority research areas.

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Oct 16th, 3:30 PM Oct 16th, 4:00 PM

Aspen fire ecology and climate change: Disturbance dynamics in an uncertain future

USU Eccles Conference Center

Aspen is the only deciduous tree species with substantial extent across much of the western United States, and decline of aspen woodlands due to climate change would likely alter ecological processes and result in cascading losses of animal and plant species in the region. Recent aspen mortality events in the western U.S. might be harbingers of future aspen disturbance dynamics under climate change, and some climate-based vegetation models suggest substantial loss of aspen over the next several decades. However, the role of future disturbance, particularly fire, complicates our ability to predict aspen distribution and productivity under climate change. Aspen is typically seral to conifer tree species, re-sprouts prolifically after fire and, thus, is often considered to be a fire-dependent species. However, some aspen populations may be stable in the absence of fire, and a recent review suggests at least five aspen fire regime types are possible. Thus, although hotter and drought-prone future climates may increase aspen mortality in some locations (e.g., at lower elevations), these same climate conditions are also predicted to increase wildfire activity across much of the western United States, and this could be beneficial to aspen in other locations (e.g., at higher elevations where conifers now dominate). Here, I present an overview of aspen-fire dynamics in the western U.S., including describing different aspen fire regimes, and discussing how future climate-fire interactions might affect aspen populations. I also present preliminary modeling results as a case study for potential changes in aspen distribution and abundance under alternative future climate scenarios and fire regimes in the northern Great Basin. I then discuss the relevance of this research to aspen restoration efforts, highlight key areas of scientific uncertainty, and suggest high-priority research areas.

http://digitalcommons.usu.edu/rtw/2013/October16/2