Treesearch

Whitebark pine (Pinus albicaulis) populations are declining across western North America due to synergies of disturbances, both natural and anthropogenic. Losses at treeline may result in significant changes to the upper subalpine zone, which may result in a regime shift, thus affecting the ecological goods and services whitebark pine systems provide for other species, including humans. Management and restoration should acknowledge the coupled social-ecological dynamics of high-elevation forest systems. Resilience is proposed as an appropriate framework for understanding social-ecological...

Efforts to maintain and restore whitebark pine (Pinus albicaulis) forests in western North America have increased dramatically over the last two decades and now include the planting of nursery-grown rust resistant seedlings in openings and burned areas. Over 200,000 nursery seedlings have been planted in the western U.S. but survival rates are low and in many areas approach zero. One possibility for enhancing seedling survival is application of mycorrhizal fungi in the greenhouse before out-planting. All pines require ectomycorrhizal fungi (ECM) to survive in nature, including whitebark pine.

The imminent invasion of the non-native fungus, Cronartium ribicola J.C. Fisch., that causes white pine blister rust (WPBR) and the current mountain pine beetle (Dendroctonus ponderosae Hopkins, MPB) epidemic in northern Colorado limber pine forests will severely affect the forest regeneration cycle necessary for functioning ecosystems. The slow growth and maturity of limber pine enables trees to persist on the landscape for centuries, but without sufficient regeneration opportunities these traits will inevitably hinder the ability of limber pine to adapt to novel stresses such as WPBR or...

Whitebark pine (Pinus albicaulis) and limber pine (Pinus flexilis) are keystone species important to watersheds, grizzly and black bears, squirrels, birds, and other wildlife. Both high elevation five-needled pines have dramatically declined in Glacier National Park primarily due to white pine blister rust (Cronartium ribicola) and fire exclusion, with mountain pine beetle (Dendroctonus ponderosae) as a potential threat. In 1997, we began collecting seed from trees that show phenotypic rust resistance in order to establish a restoration and monitoring program to maintain healthy whitebark...

Whitebark pine (Pinus albicaulis) has been declining across much of its range in North America because of the combined effects of mountain pine beetle epidemics, fire exclusion policies, and widespread exotic blister rust infections. Whitebark pine seed is dispersed by a bird, the Clark's nutcracker, which caches seed in open, pattern-rich landscapes created by fire. This study was initiated in 1993 to investigate the effects of various restoration treatments on tree populations, fuel dynamics, and vascular plant cover on five sites in the U.S. northern Rocky Mountains. The objective of...

Whitebark pine is a keystone species of high elevation forests in western North America that is experiencing rapid decline due to fire exclusion policies, mountain pine beetle, and the introduced pathogen, white pine blister rust. Restoration activities include collecting cones and growing seedlings from individuals that show mechanisms for resistance to blister rust infections. Collecting viable whitebark pine seeds is challenging due to high rates of cone harvest by wildlife prior to seed maturation. This has led to the practice of placing protective coverings over the cones early in the...

In 2005, Forest Health Protection (FHP) initiated a rangewide health assessment for whitebark pine (Pinus albicaulis). This assessment summarized the forest health condition of whitebark pine throughout its range and also documented information needs, potential restoration strategies, and challenges to restoration that need to be addressed (Schwandt 2006). This led to the creation of a national whitebark pine restoration program coordinated by FHP.

Whitebark pine (Pinus albicaulis) is a critical species in many high elevation ecosystems and is currently in serious decline due to white pine blister rust (Cronartium ribicola), mountain pine beetle (Dendroctonus ponderosae), and competition from other species (Schwandt 2006; Tomback and Achuff 2010; Tomback and others 2001). Many areas needing restoration are very remote or in areas where the planting of seedlings may not be logistically or politically feasible. Consequently, it is important to determine if direct planting of seeds is practicable and which treatments enhance germination...

Resistance to white pine blister rust based on a hypersensitive response (HR) that is conferred by a dominant gene has been identified as functioning in needles of blister rust-resistant families of sugar pine, western white pine and southwestern white pine. The typical HR response displays a characteristic local necrosis at the site of infection in the needles during the early stages of needle colonization by Cronartium ribicola. The localized host cell death early in the infection process is thought to prevent the pathogen from reaching the shoot tissue, thereby preventing further...

All nine species of white pines native to the U.S. or Canada are susceptible to the introduced pathogen Cronartium ribicola. Of the six high elevation white pine species, the severe infection and mortality levels of Pinus albicaulis have been the most documented, but blister rust also impacts P. aristata, P. balfouriana, P. flexilis and P. strobiformis; only P. longaeva has not been documented to be infected in its natural range. Early evaluations of resistance included relatively few seedlots and demonstrated that these species have some genetic resistance to blister rust but generally...