Populus tremuloides mortality near the southwestern edge of its range

Abstract

Mortality and crown dieback of quaking aspen (Populus tremuloides) were extensive on the Williams Ranger District, Kaibab National Forest in northern Arizona. We collected data from a random sample of 48 aspen sites to determine the relationship of predisposing site and stand factors and contributing agents to ramet mortality. Mortality of overstory (P10.1 cm DBH) aspen stems averaged 50% (44% by basal area). Pine-oak type aspen stands suffered greater basal area mortality (57%) than stands in mixed conifer type (38%). An average of 48% of live overstory aspen stems had >33% crown dieback, and mortality significantly increased with increasing crown dieback. Based upon univariate relationships, elevation was the most significant site factor and relative conifer basal area was the most significant stand factor related to overstory mortality. Canker diseases and wood-boring insects were significantly related to overstory mortality. Sapling (≥5.1-10.1 cm DBH) and tall regeneration (80% and 70%, respectively), while short regeneration (

Citation

Zegler, Thomas J.; Moore, Margaret M.; Fairweather, Mary L.; Ireland, Kathryn B.; Fule, Peter Z. 2012. Populus tremuloides mortality near the southwestern edge of its range. Forest Ecology and Management. 282:196-207.