Whitebark Pine: A species at risk in western Alberta

Josh Davis, Pincher Creek Voice

Reg Ernst at Lebel Mansion
J. Davis photo

On Wednesday September 4 the Castle-Crown Wilderness Coalition delivered a presentation on Whitebark Pine at the Lebel Mansion in Pincher Creek.  Botanist Reg Ernst of the Alberta Wilderness Association, equipped with a slide show, discussed threats to this vital organism, as well as protective efforts that may be taken to preserve the species.

Whitebark is listed as endangered both provincially and federally. Whitebark Pine is typically at the highest-elevation of pine tree, and is important for regulating stream flows by slowing the process of snow melting and run down. Additionally, Whitebark seeds provide high fat, high protein meals for bears stocking up in preparation for hibernation, and serves as important cover for other animals living in its ecosystem. Unlike its relative, Limber Pine, Whitebark Pine cones cannot open on their own. As a result, it relies exclusively on the small, black billed bird know as Clark’s Nutcracker to propagate its seeds. If Whitebark Pine declines into extinction, the Clark's Nutcracker will lose an important source of food.


The three greatest threats to Whitebark are Blister Rust, drought and fire exclusion. Ernst explained that the according to his surveys, Mountain Pine Beetle infestation is mostly a non-issue here in Alberta. Blister Rust is a caused by cronartium ribicola, a species of fungus accidentally introduced into the Rocky Mountain’s ecosystem when Western White Pine trees were brought over from France. As Whitebark has little to no genetic resistance to this rust, mortality rates are high among affected trees. Over 51% of trees surveyed showed signs of Blister Rust, while 29% were already dead. This survey was taken over 20 plots of land, including a total of 984 Whitebark Pine trees.

Fire exclusion has led to fir and spruce species to become dominant in many areas where Whitebark once prospered. Whitebark evolved in an environment of naturally occurring wildfires, which clears up land in areas where Clark’s Nutcracker plant seeds. Human intervention has created an environment in which Whitebark Pine cannot effectively compete. Local drought creates further stress on Whitebark Pine strains infected with Blister Rust. These effects may be further exacerbated by potential climate changes in the future.

In order to combat the decline of Whitebark, several recommendations were made. There are attempts to propagate rust resistant trees through cone collection, seeking trees that have successfully fought off infection in order to improve Whitebark’s resistance over generations. Additionally, Ernst suggested manual removal of competing species. Removal of immature infected branch cankers has been suggested, but may be ineffective if it reaches the trees main body.

A 2 day conference is to be hosted in Kimberly, BC on September 14 and 15 on Whitebark Pine preservation.