White Bark Pine
Ben Roth Installs Environmental Art in Teton Village
Local artist Ben Roth has installed “Fallen,” a 20’ high by 60’ long sculpture located just off the Pathway in Teton Village. The sculpture was constructed with multiple branches from one deceased whitebark pine tree found at an elevation of about 9,000 feet at Jackson Hole Mountain Resort. A team including Charley Gorskey, an experienced climber and budding arborist and the Jackson Hole Mountain Resort trail crew employees cut the massive branches using climbing gear and transported them by truck to the base. Over three days, with the help of, Watsabaugh and the JHMR Trail Crew, Roth installed the sculpture and a viewing bench.
The Fight Against Whitebark Pine
In conjunction with the Bridger Teton National Forest, JHMR is trying to preserve the amazing “grandfather” Whitebark Pine trees which grow above 8500 feet at the Resort.
Whitebark pine (Pinus albicalus) is a slow growing, long-lived, stone pine of high-elevation forests and timberlines of the northwestern United States and southwestern Canada. The oldest whitebark pine exceeds 1275 years in age and occurs in the mountains of central Idaho (Perkins and Swetnam 1996).
Because of the dependence of many animal species on this food source, whitebark pine is considered keystone species of the subalpine forests (Tomback et al. 2001). Whitebark seeds develop within indehiscent cones that are harvested by Clark's nutcracker (Nucifraga columbiana). Nutcrackers pry cone scales with their bills and slip seeds into a pouch under their tongues for transport. The birds cache as well as consume seeds and those seeds not retrieved from caches may germinate and become established as seedlings. Whitebark pine seeds weigh an average 180 mg compared to 3 – 13 mg for the seeds of other trees in subalpine whitebark pine forests. The whitebark seeds also contain by weight about 52% fat, 21 % carbohydrates, and 21% protein (Lanner, 1996). Their large size, high nutrient content, and durability, remaining viable when buried for 1 year or more in nutcracker caches or squirrel middens, make whitebark pine seeds an attractive food source. For example, black bears (Ursus americana) and the endangered grizzly bear (Ursus arctos horriblis) raid caches or middens for the energy-rich seeds.
White pine suffers from three distinct threats that have severely reduced its populations, which JHMR is attempting to control in collaboration with the U.S. Forest Service. White pine blister rust, a fungal disease caused by the pathogen Cronartium ribicola, was inadvertently introduced to Vancouver, British Columbia in 1910. The alternate host for the fungus is Ribes genus, otherwise known as current plants. Damage to plants includes mortality, topkill, branch dieback, and predisposition to attack by other agents, including bark beetles. Two methods of control are employed at JHMR in coordination with the US Forest Service: (1) cutting blisters found on branches over 10 cm from the main trunk or bole; (2) identifying phenotypically resistant whitebark pines (called "plus" trees), gathering their seed to propagate “plus” tree seedlings in a nursery, and outplanting seedlings in suitable sites.
Intermittently for over a hundred years, widespread outbreaks of native mountain pine beetle have killed whitebark pine. For example, in 2004 in the Greater Yellowstone Ecosystem, more than 700,000 whitebark pines were effectively girdled by beetles. Individual whitebark pine trees can be protected by application of verbenone, a terpene repellent naturally found in plant tissue, prior to annual spring flights of beetles overwintering beneath tree bark. In 2010, over 250 trees at JHMR were sprayed, and trees outside of the spray range had pheromones applied to also deter beetle landing and aggregation.
Advanced succession is another factor leading to regional declines in whitebark pine communities, compounding losses caused by blister rust and mountain pine beetles. Decades of fire suppression have led to progressive successional replacement of whitebark pine by more shade-tolerant trees, such as spruce and fir. JHMR may address this issue with prescribed fire in the future in consultation with the U.S. Forest Service. Against multiple odds, JHMR is working to maintain the ecological character of alpine Rocky Mountain forests.
Lanner, R.M. 1996. Made for each other: A symbiosis of birds and pines. New York, NY: Oxford University Press.
Perkins, D.L. and Swetnam, T.W. 1996. A dendro-ecological assessment of whitebark pine in the Sawtooth-Salmon region, Idaho. Canadian Journal of Forest Resources 26:2123-2133.
Tomback, D.F., Arno, S.F., and Keane, R.E. eds. 2001. Whitebark Pine Communities: Ecology and Restoration. Washington, D.C.: Island Press.
Watch this space for further updates about this program and the prestigious “plus” trees and more.
Check out www.treefight.org for more information!