Taking the long view and acting now - prioritizing management of high elevation five-needle pines

Abstract

Some of the most vulnerable ecosystems include subalpine forests where growing space declines with elevation and species distributions are defined by distinct climatic gradients and biotic interactions. Climate change is projected to be rapid and heightened in these habitats, highlighting the importance of genetic diversity and adaptive capacity of plant species that occupy them (Millar et al. 2007). The North American high elevation five-needle white pines (Fig. 1) define the forest-alpine ecotone in many mountain systems and provide watershed protection and wildlife habitat. They are also being challenged be an invasive fungal pathogen, Cronartium ribicola, that was introduced to North America in the early 1900s and causes the lethal disease white pine blister rust (WPBR) on five-needle white pines (subgenus Strobus; Fig. 2). All the high elevation five-needle white pines of North America are susceptible to C. ribicola. The disease spread rapidly through host ranges in the moist forests of the northwest and east and continues to spread, though more slowly, into the drier habitats of the southern Rockies, Great Basin and southwest. WPBR has killed many five-needle white pines in the north although it wasn’t detected in Colorado until the late 1990s, and has yet to be found on trees in Utah or most of Great Basin (Fig. 3). As the pathogen continues to spread, and the disease intensifies, the populations currently less affected may too follow the same trajectory as those to the north if effective management intervention is not pursued.

Citation

Schoettle, Anna. 2019. Taking the long view and acting now - prioritizing management of high elevation five-needle pines. Mountain Views (CIRMOUNT). 13(2): 2-7.