Ponderosa Pine Restoration at Lick Creek

See: A Century of Change in a Ponderosa Pine Forest for more information about the Historical Photopoints in the Lick Creek Drainage.

The Lick Creek Demonstration/Research Forest (Lick Creek) on the Darby Ranger District of the Bitterroot National Forest, MT provides a unique opportunity to assess 25-year-effects of burning and cutting restoration treatments. In 1991, a cooperative venture among the Bitterroot National Forest, University of Montana, and Forest Service Intermountain Research Station (now Rocky Mountain Research Station) initiated a new research experiment with seven prescribed burning and cutting treatment variants to test restoration alternatives in restoring the site’s ponderosa pine vegetation community and reduce fuel loads to historically-appropriate levels. Silvicultural treatments were implemented in 1992, followed by prescribed burning in 1993 and 1994, under a fully replicated experimental design involving randomization of treated units and a permanent, systematic plot sampling network.

The goals of the initial project were to increase knowledge of forest vegetation and fuel dynamics following restoration treatments, study how these differ among restoration treatment alternatives, and gain understanding of the efficacy and longevity of prescribed treatments. Study results have provided managers with guidelines for restoring ponderosa pine systems in the northern Rocky Mountain region.

In 2015 the Joint Fire Science Program funded a re-measurement of the Lick Creek study plots. This new work will result in many benefits, including:

• Complete 25-year (1991-2016) effects of seven silvicultural cutting and burning treatments on fuels and vegetation.
• Archived data with complete documentation of study protocols to encourage future data analysis.
• Demonstration site that is easily accessible to a large population center to communicate forest restoration and management treatment results to both the public and managers.
• Photo-history of the effects of fire exclusion and restoration treatments from 1909 – 2016.

In addition, re-measurement gives added value to past data collection through modern data analysis techniques to examine treatment effects on aspects of forest resilience, including:

• Resistance to bark beetle outbreaks: Mountain pine beetle populations are currently high on the Bitterroot National Forest (Egan et al. 2013), providing a unique opportunity to directly test treatment effects on resistance to bark beetles, a natural disturbance enhanced by warming and drought associated with climate change. This is possible because we have past censuses of tree mortality causes through 2005. We will combine these results with similar studies of mid-term treatment effects in the region (Hood et al. In Prep) to help inform how management actions impact forest resistance to bark beetles.
• Resilience from drought: We will apply newly developed methods (Lloret et al. 2011) to quantify tree resilience from drought in the different treatments. This novel method has already been advocated as a very promising resilience metric for use in the Sierra Nevada (North and Stine 2012).
• Resilience from wildfire: Potential fire behavior using canopy fuel loading and different weather scenarios has never been simulated for Lick Creek. Methods to quantify canopy fuels were not available at the time the study was established, but all required data to calculate canopy fuels were collected. Re-measurement will allow us to assess differences in fire hazard among treatments over time using modern fire behavior systems (e.g., BehavePlus, FFE-FVS, Nexus) with real surface, canopy, and vegetation data as inputs to models.
• Treatment longevity and successional trajectories: Ten-year physiological responses to treatments reported in Sala et al. (2005) indicated that trees in the cutting and burning treatments had less water stress and faster growth compared to trees in the control treatment. Re-measurement will allow us to assess the degree to which treatment-specific differences in vegetation characteristics have changed over time. More sophisticated multivariate analyses techniques are now available that allow incorporation of both vegetation and fuel variables to examine the successional trajectories of treatments over 25 years.