Pacific Southwest Research Station

Threats to White Pines

The introduced fungus Cronartium ribicola, cause of white pine blister rust (WPBR), is the greatest threat to sustainability and survival of white pines. Genetic resistance provides the best chance for survival of white pines under threat of WPBR. This study provides opportunity to test whitebark pine from established locations, to develop a seedbank of genetically diverse material for the Lake Tahoe basin, and to inform strategies for conserving and restoring these trees.

Full title: Natural and anthropogenic threats to white pines from lower montane forests to subalpine woodlands of the Lake Tahoe basin: an ecological and genetic assessment for conservation, monitoring, and management

Proposal [pdf-769KB]      Presentation [pdf-3.2MB]

Lead Researchers: Detlev R. Vogler, Pacific Southwest Research Station; Patricia E. Maloney, University of California, Davis; Annette Delfino-Mix, Pacific Southwest Research Station; Joan Dunlap, USDA-Forest Service, Placerville Nursery; Valerie Hipkins, Geneticist, USDA-FS, National Forest Genetics Lab

Goals

1. Identify and conserve trees with genetic resistance.
2. Identify populations that are declining owing to lowered recruitment and reproduction.
3. Test reforestation strategies of planting seeds versus planting seedlings.

Sites: 13 transects, 0.5- to 1.0-ha plots encompassing three 15- by 15-m regeneration plots, and 40- by 40-m forest vegetation plots

Timeframe: October 2007 through May 2011 (3.5 years)

Products

1. Report on genetic structure and diversity of populations
2. Report on severity of threats from white pine blister rust infection
3. Data on mechanism and frequency of WPBR resistance
4. Seed bank of local and potentially rust-resistant seed
5. Species and site-specific demographic models
6. Identification of WPBR wave years
7. Evaluation of recruitment dynamics for each species
8. Establishment of long-term ecological monitoring plots
9. Testing of practical restoration treatments