White pine blister rust is a disease caused indirectly when mountain pine beetle destroys lower elevation pine stands forcing bears and other critters to higher elevations in search of flood.
I thought the following point about de-forestation was interesting.
“…..The wider ecological effects could be serious. These forests slow the rate of spring snowmelt; without them, the spring runoff will happen faster and streams and rivers will see reduced flow and higher temperatures later in the season…. ”
Full New York Times editorial about the effects of mountain pine beetle on bears.