|A perfect storm of several threats — white pine blister rust, mountain pine beetles, climate change and absence of fire — are jeopardizing the health of our high-elevation forests.
- White pine blister rust is a non-native and deadly disease preventing nutrient and water dispersion throughout white pine trees, which ultimately reduces cone and seed production and severely limits regeneration. Only a small number of white pine trees are naturally resistant to white pine blister rust.
- Mountain pine beetles are a native pest that bore into a tree’s bark, killing the tree. As a result of our warming atmosphere, these beetles have shortened their hibernation period, increased their population and reproduction rate and migrated into higher elevations, attacking tree species that previously were rarely exposed to the beetle.
- Our changing climate limits where these high-elevation pine can flourish, as they require cooler, high-elevation mountain conditions. Also, these trees are more vulnerable to invaders like blister rust and mountain pine beetles because of the effects of climate change, including warmer temperatures and drought.
- Decades of preventing natural fires has created denser forests, which allow pine beetles more trees in which to roam and reproduce. These same policies also stymie the growth of the white pine population, which depends on naturally occurring disturbances like fire to clear open spaces in which they can grow.
Read more about how these threats attacking these forests and why you
see red or graying trees.
How are the unprecedented outbreak of mountain pine beetles and climate change connected? Dr. Diana Six delves into the connection in our web-exclusive article “Mountain Pine Beetle Expansion in the West.”
Pine tree tries to combat a mountain pine beetle by pitching out resin.