Juniper is relatively resistant to wood rots and has few other serious defects. Pinyon, however, is affected by rots and other diseases and should be inspected carefully. Because of the inherent differences in these tree species, they are discussed separately. Areas with predominant pine cover are commonly used for campgrounds and picnic areas. From the standpoint of potential tree hazards, the major difference between lodgepole pine and ponderosa pine is that lodgepole pine has very thin bark which is easily damaged resulting in increased susceptibility to decay.
Dwarf mistletoe is the major disease of pines in the Rocky Mountains.
Large witches'-brooms should be removed to eliminate this hazard and improve tree vigor. Wood-rotting fungi are common in pines. Burls and cankers commonly occur on pines, but do not constitute a hazard unless they are so extensive as to weaken stem structure or are complicated by rot. Increment cores should be taken to determine the amount of sound wood in trees exhibiting signs of decay. Aspen stands usually contain many defective trees.