Treesearch

The slow growth and long generation time of the five-needle pines have historically enabled these trees to persist on the landscape for centuries, but without sufficient regeneration opportunities these same traits hinder the species' ability to adapt to novel stresses such as the non-native disease white pine blister rust (WPBR). Increasing the frequency of resistance to WPBR is the foundation for options to sustain five-needle pine species in the presence of the pathogen. Depending on the condition of the ecosystems, increasing resistance can be achieved via outplanting resistant...

Across western North America mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae, Scolytinae), populations are growing at exponential rates in pine ecosystems that span a wide range of elevations. As temperature increased over the past several decades, the flexible, thermally-regulated life-history strategies of mountain pine beetle have allowed for increased population success in numerous habitats. Of particular concern are the high-elevation five-needle white pines that are currently being infested. In a recent study of high-elevation whitebark pine forests, mountain...

Whitebark pine (Pinus albicaulis), a keystone high-elevation species, is currently at risk due to a combination of white pine blister rust (WPBR) (Cronartium ribicola), forest succession, and outbreaks of mountain pine beetle (MPB) (Dendroctonus ponderosae). While recent mortality is often quantified by aerial detection surveys (ADS) or ground surveys, little information is presented to describe what stands look like following MPB outbreaks. This information may help prioritize areas for restoration. In 2008 and 2009, the severity of MPB impacts was measured in 42 whitebark pine stands in...

We initiated a multi-year project to protect individual cone-bearing whitebark pines (Pinus albicaulis) from mountain pine beetle (MPB), Dendroctonus ponderosae (Hopkins), attack with the anti-aggregating pheromone, verbenone (4,5,5-trimethylbicyclo [3.1.1] hept-3-en-2-one). Our objective was to protect trees through the course of the epidemic that began ca. 2000 in central Idaho. The study population was a subalpine stand of whitebark pine at 9,400 feet elevation near Clayton, ID. Associated conifer species included lodgepole pine, Douglas-fir and subalpine fir.

Verbenone is a known anti-aggregation pheromone of mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, and has been tested in protecting susceptible host trees from attack since 1988. Inconsistent performance of verbenone during field trials caused formulations and release devices to change through time, resulting in three products currently registered with the Environmental Protection Agency - two pouch formulations containing 7 grams of verbenone that are stapled to tree boles (available from Synergy Semiochemicals Corp. and Contech Enterprises, Inc.), and a flake formulation...

Conservation genetics examines the biophysical factors influencing genetic processes and uses that information to conserve and maintain the evolutionary potential of species and populations. Here we review published and unpublished literature on the conservation genetics of seven North American high-elevation five-needle pines. Although these species are widely distributed across much of western North America, many face considerable conservation challenges: they are not valued for timber, yet they have high ecological value; they are susceptible to the introduced disease white pine blister...

Levels of genetic variation within and among 163 individual- tree collections and one bulk lot of whitebark pine were estimated using isozymes, mitochondrial DNA and chloroplast DNA; 79 of the samples are also part of a common garden study evaluating survival, rust resistance, late winter cold hardiness, and early height-growth. Within the species, 100 percent of the isozyme loci are polymorphic, with the number of alleles per locus (Na) equal to 4.0. Genetic diversity is high (He = 0.271) relative to other conifers in the same forest cover type and is comparable to quaking aspen (Populus...

Whitebark pine (Pinus albicaulis) decline has altered trophic interactions and led to changes in community dynamics in many Rocky Mountain subalpine forests (McKinney and Tomback 2007). Here we discuss how altered species interactions, driven by disproportionate whitebark pine mortality, constrain the capability of whitebark pine forests to contribute genetic material to subsequent generations. The degree to which whitebark pine forests are reproductively limited, however, depends in large part on tree species composition and forest structure. The results of these changed dynamics have...

Whitebark pine (Pinus albicaulis), one of five stone pines worldwide, is found at treeline and subalpine elevations in the mountains of western North America (McCaughey and Schmidt 2001). Considered a keystone species, it helps maintain subalpine biodiversity, protects watersheds and promotes post-fire regeneration (Tomback and others 2001). The Clark's nutcracker (Nucifraga columbiana) and whitebark pine are co-evolved mutualists (Tomback 1982). Nutcrackers remove seeds from whitebark pine cones and cache them in high- and low-elevation forests and terrain, returning to feed on the seeds...

Limber pine (Pinus flexilis) reaches the northern limit of its range at about 52 degrees latitude in Alberta (AB) and 51 degrees latitude in British Columbia (BC). Most populations are found on the eastern slopes of the Rocky Mountains, with a few disjunct populations west of the Continental Divide in southeastern BC.