The bark may crack or scale off as it slowly heals, or the tree may be killed. Too much water can be as much of a problem as not enough. However, during flood conditions these air spaces fill with water and the tree roots can literally drown. Trees that are naturally adapted to riparian , or streamside, areas are usually able to survive a lengthy period of flooding, but most forest trees will be damaged or killed. Local flooding is not simply restricted to storm conditions, but can occur as a result of beavers building dams.
Fires can be beneficial or highly damaging, depending on their intensity.
A low intensity fire can effectively thin a stand by removing younger trees and species that are not fire resistant, such as grand fir and western hemlock. However, trees that remain after a fire may be stressed from charring. Pines that have been scorched are often attacked by red turpentine or other bark beetles, which can finish them off. Wind can be a problem in stands that have recently been thinned or are adjacent to clearcuts. Rather than thinning drastically once, a forest manager can thin regularly through the life of a stand, which will permit the trees to grow strong.