Patterns of White Pine Regeneration after Fire and its Implications for Forest Establishment in the Presence of White Pine Blister Rust

National Fire Plan Project 01.RMRS.B.6

GOALS AND OBJECTIVES

Bristlecone pine and limber pine are white pines that are appreciated by the public – they are often used as symbols of perseverance, tolerance and wildness. These species are now threatened by a non-native invasive pathogen and their ecosystems are at risk.
The goal of this program is to gain and provide information to facilitate the development of proactive management options to mitigate the impacts of the exotic blister rust on white pine ecosystems and reforestation after fires. In addition, this program is expanding and learning from the experiences with whitebark pine.

Limber Pine
Pinus flexilis Engelm

Bristlecone Pine
Pinus aristata Engelm

THE THREAT OF A NON-NATIVE INVASIVE PATHOGEN

White pine blister rust (Cronartium ribicola) was introduced to the Vancouver area of North America in the early 1900s and is spreading southward through the white pine ecosystems. Blister rust causes high rates of mortality in American white pines.
White pine blister rust was identified in Colorado in 1998 on limber pine and the advancing infection front is only 60 miles from the distribution of bristlecone pine. The distribution of Rocky Mountain bristlecone pine almost entirely in Colorado.

Mortality caused by the rust

Blister rust on limber pine

Implications on ecosystem function

White pine blister rust and the resultant pine mortality is likely to affect ecosystem boundaries (treelines), post-fire successional trajectories, stability of plant communities and structure in xeric habitats as well as populations of birds, bears, and red squirrels which feed on white pine seed.

The role of fire in possible management strategies

Fire may provide a management tool to aid in the coexistence of white pine populations with the exotic pathogen white pine blister rust.
Protecting seed source stands from wildfire while creating or using nearby burns as colonization opportunities to accelerate natural selection of rust resistant genotypes may mitigate the ecological impacts of the rust on white pine ecosystems.

Bristlecone (left) and limber pine (right) seed

THE RESEARCH PROGRAM

FY01 - Present

The program is applying ecological, physiological, genetic and meta-population approaches to improve our ability to develop and assess potential management and conservation options for white pine ecosystems. Four research areas are actively being studied.

Cone cages must be used for seed collection

Regeneration Dynamics

Field studies are being conducted to examine the spatial and temporal regeneration dynamics of white pine and Ribes ssp. and the effects, or potential effects, of the rust following the Yellowstone fires of 1988, Packer Gulch fire of 1978 (CO), Ouzel fire of 1978 (CO), and the Topaz fire of 2002 (CO).
Partners with RMRS include Univ. of Colorado at Denver (Denver, CO) and Yellowstone National Park.

Adaptive Variation of Pines

Seeds from throughout the range of bristlecone pine are being grown to provide an understand of landscape scale adaptive variation and provide information for seed transfer guidelines. The distribution of stress tolerant traits are also being studied among the seed sources.
Partners with RMRS include Colorado State Forest Service Nursery (Ft. Collins, CO) and USDA-ARS National Center for Genetic Resources Preservation (Ft. Collins, CO)

Rust resistance

Tests are being conducted to identify bristlecone and limber pine trees that are resistant to the rust. Because the functioning of white pine ecosystems depend on the ability of the trees to withstand the harsh environment we are also conducting physiological studies to improve our understanding of the environmental tolerances of the future rust-resistant populations.
Partners with RMRS include Canadian Forest Service Laurentian Forestry Centre (Quebec) and USDA FS PSW Institute of Forest Genetics (Placerville, CA).

Pine Population Genetics

Building on the adaptive variation and rust screening studies, molecular genetic approaches are being used to further assess the genetic structure of bristlecone and limber pine populations and to examine gene flow and pine seed source/colonization dynamics across the landscape.
Partners with RMRS include USDA-ARS National Center for Genetic Resources Preservation (Ft. Collins, CO) and Rocky Mountain Tree-Ring Research, Inc. (Ft. Collins, CO)

For more information on this program contact:
Dr. Anna W. Schoettle
Rocky Mountain Research Station
240 West Prospect Road, Fort Collins, CO.
(970) 498-1333 aschoettle@fs.fed.us.