WPGA-Whitebark Pine Growth Analysis

Whitebark pine is disappearing from the upper subalpine landscape due to three main factors - white pine blister rust (WPBR) caused by the fungus Cronartium ribicola, mountain pine beetle (Dendroctonus ponderosae) outbreaks, and successional replacement by more shade-tolerant species. WPBR is an exotic disease that attacks most five-needle pines, but is particularly deadly to whitebark pine. These factors have contributed to a nearly rangewide decline in whitebark populations; as a result, the species was recently listed as a candidate species under the United States Endangered Species Act (US Fish and Wildlife Service 2011).

Restoration is the only solution to combat declining whitebark pine populations. Managers are implementing a variety of treatments across the landscape to encourage whitebark pine regeneration and survival such as though the use of selected cuttings and perscribed burning. The objective of this study is to determine how immature whitebark pine respond release treatments, and if there are stand, site, or tree characteristics that managers could use to identify other areas where treatment would be effective. Gathered field data will allow us to assess the effectiveness of release treatment methods in immature whitebark pine stands and allow us to determine if the released trees share any phenotypical characteristics. Tree cookies and cores collected from seedlings, saplings, and poles, in treated areas will be analyzed using an intervention analysis and stem analysis (Keane and others 2007) to determine if and how the treated trees have released, and which of the site, stand, and tree characteristics are associated with the release.

While it is known that older whitebark pine respond well to release treatments (Keane and others 2007), it is unclear if seedling and sapling whitebark will respond or if only those with select phenotypical traits will do the best. In order to address this question we will extensively photograph and document the physical characteristics of the trees which are sampled. Ideally, we will use the photographs to create a field guide that managers will be able to use select stands where release treatments have potential be the most effective based on the phenotypical characteristics of the trees in the stand. We will locate plots in as many high elevation areas as we can travel to during the summers of 2016 and 2017. From these data we should be able to determine if whitebark pine respond positively to release treatment methods. Results from this study can be used to help guide management actions to restore this species across its range.

For geographical information on this project and how it fits with other Fire Lab Whitebark Pine research, visit the Whitebark Pine Story Map.