An aspen-dominated forest in Alberta in late August.

Trembling aspen is the most widespread tree species in North America. It is also common in the aspen parkland. Massive mortality and dieback has been described for aspen forests in Colorado (Anderegg et al. 2012, 2013) and Alberta (Michaelian et al. 2011). How this dieback relates to drought, cavitation resistance and other hydraulic traits is an active area of research.

Photo: Uwe Hacke