Modeling Forest Change and Management Alternatives on a Restored Landscape

Final Report to the Joint Fire Sciences Program

Project ID Number 06-3-3-05

Caption: Mt Trumbull ecosystem restoration project in northwestern Arizona. This study modeled management alternatives and climate change effects over a century in a treated forest landscape (foreground) and untreated control landscape (background). Photo: J.P. Roccaforte.

Authors:

Corinne Diggins, Peter Z. Fulé, W. Wallace Covington

School of Forestry and Ecological Restoration Institute
Northern Arizona University
P.O. Box 15018, Flagstaff AZ 86011
Tel 928-523-1463, Fax 928-523-0296, This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Jason Kaye

The Pennsylvania State University, Department of Crop and Soil Sciences
116 ASI Building, University Park, PA 16802-3504
Tel 814-863-1614, This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Download Full Report (IE)

Links:
ERI Mount Trumbull Research Page
Bureau of Land Management-Arizona

FUTURE CLIMATE AFFECTS MANAGEMENT STRATEGIES FOR
MAINTAINING FOREST RESTORATION TREATMENTS

ABSTRACT Maintenance of forest treatments is a critical issue for forest management because millions of ha of forests adapted to frequent-fire regimes are being treated or proposed for treatment to reduce fuel hazards and restore ecosystem processes. We modeled forest change for 100 years on actual restored and control ponderosa pine forest landscapes in the southwestern USA, comparing alternative management regimes that included prescribed burning, tree cutting, and no-management. We applied the Forest Vegetation Simulator, a widely used model, both in its standard form and with modifications to simulate the effects of two levels of predicted climate change causing reduced tree growth and increased mortality. Climate change effects had the greatest influence on the future forest. Under any scenario, the no-management alternatives led to the highest forest density after 100 years. In the absence of climate change effects, several management regimes, including the application of frequent surface fires emulating the historical frequency (~ 5 yr), were capable of maintaining future forest structure within a target range of variability. Simulations that accounted for climate change effects, however, indicated that burning intervals should be lengthened (~ 20 yr) and future tree thinning should be avoided to minimize forest decline. The decisions that managers make in the near future have long-term ramifications for the forest. Until more information is available about future climate and its effects, a conservative management strategy using surface fire at relatively long intervals could maintain beneficial treatment effects without foreclosing options for future forest structure; this approach may also have advantages in terms of reduced cost and smoke outputs. While it has been widely predicted that future climate conditions will support more burning (warmer, drier fuels, longer fire season), our modeling suggests that the production of fuels will decline, so there will eventually be a tradeoff between increased fire driven by climate vs. less fuel, also driven by climate.