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Three modes of aspen regeneration are known to occur on the Ashley National Forest. Many stands, especially serial aspen, depend upon large-scale catastrophic disturbances to trigger new sprouting and maintain dominance on a site. Without fire and other catastrophic events, aspen decline in the western United States is expected and has been well documented. Continuous regeneration is relatively uncommon mode of aspen regeneration. Stands with this capability are multi-tiered with continuous sprouting occurring underneath the mature tree canopy. On the Ashley National Forest, relatively few aspen stands with continuous regeneration have been observed, which leads us to believe that there are less stands with this capability than was documented in western Colorado (Kruzel et. al. 2007). Episodic regeneration is found to be common in most persistent aspen stands. In the absence of fire and other catastrophic events, pulses of new sprouting following senescence has been repeatedly documented across the Ashley National Forest. Senescing aspen stands weaken or remove apical dominance, which typically stimulates root suckering. In most aspen stands, apical dominance is the controlling factor in aspen sprout abundance and survival (Schier et al. 1985). Closed stands typically produce a few, inconspicuous sprouts each growing season, but these seldom survive to maturity.� Such conditions persist until catastrophic disturbances or dieback during senescence remove or deplete aspen canopies. To expect numerous sprouts in all mature and vigorous stands is contrary to the apical dominance concept described by Schier (1985a).