Whitebark Pine (Pinus albicaulis)
Have you ever eaten pinyon pine nuts on a salad? Most autumns, whitebark pines are loaded with cones holding a very similar nut, and any animal who depends on fat to make it through the winter knows when the whitebarks are ripe.
Whitebark pines don’t look like much. They are usually less than twenty feet tall in the Waterton-Glacier International Peace Park. They have relatively smooth, gray bark, two-inch needles in bunches of five, and closed purplish cones. Near the treeline, they are often misshapen and scrubby looking, “bonsai-d” by the sometimes 100 mph winds into a form called krummholz. Because Clark’s nutcrackers typically cache their seeds in groups of three to five, whitebark pine stands often have trees with multiple trunks. The short, tough growing season at high elevations where the whitebark pines grow, keep the trees from growing very large. Whitebark pines in these communities can have 400 year old trees whose trunks are only 6-inches in diameter!
Whitebark pines grow best in small openings on south slopes from 2,000 to 3,000 meters (6,000 – 9,000 feet). The pines create micro-climates in these severe habitats that allow other trees to grow. Trees like the subalpine fir and Englemann spruce, which usually live in wetter and shadier habitats, eventually invade the areas where whitebark pines grow because the firs and spruces are shade-tolerant and can grow under the pines.
Whitebark pines are considered a "keystone" species because of the their importance to other organisms. In Glacier National Park, whitebark pine communities have been disappearing and their loss could have a profound effect of many other species. Read the resource brief at www.nps.gov/articles/whitebark-pine-brief.htm.
Finally, scientists in the Waterton-Glacier International Peace Park have begun to match the growth rings of the most ancient whitebark pines, some over 1200 years old, with changes in climate. Both glaciers and whitebark pines are proving to be accurate windows on the climate changes that have happened in the recent past.