Assessment of Aspen Condition of the Okanogan and Wenatchee National Forests

Aspen stands occupy less than 1 percent of the Okanogan and Wenatchee National Forests but the species is an important resource. 105 aspen stands considered to be representative of the aspen population on the Forests were surveyed in the summer of 2003 to assess their condition. Most aspen stands occupy small areas and contain small numbers of stems. 56% of the stands were estimated to cover 2 acres or less, 28% covered 5 or more acres. 56% were rated as stable, 41% were classed as successional to conifers, and 3% were rated decadent. Similarly, area occupied by living aspen stems was classed as 43% stable, 19% expanding, and 38% retreating. 24% of the stems were dead from a variety of causes. 15% of the mortality could not be identified to causal agent, 5% were killed by fire, but less than 1% was killed by diseases. 7.4% of the sprouts were dead. 47% of the stands had active sprouting. 57% of the sprouts had been browsed. Elk were believed to be responsible for the almost total lack of seedling size aspen stems on the southern-most District. Many damage agents, including canker fungi, decay, wood borers, and ungulates were found affecting aspen stems.
Coauthor Roy Magelssen