Drought a concern for aspens

Aspens along Armstrong Pass. Photos/Kathryn Reed

By Daniel R. Cluck

Concern for the health of California’s quaking aspen (Populus tremuloides) habitat has increased in recent years due to heavy wild ungulate and domestic livestock browsing, competition from conifers and other vegetation in the absence of fire, the impacts of drought and the potential negative impacts of climate change.

In response, land managers are taking inventory of California’s aspen resources and identifying the magnitude of these threats. These inventories have thus far included assessments of aspen regeneration, conifer encroachment and animal browsing as indicators of aspen health. Restoration treatments have also been implemented to rejuvenate and protect individual aspen stands. These include removal of competing conifers,
fencing, prescribed burning and/or a combination of treatments.

Spotted aspen leaves are the norm this year.

Recent California aspen studies have examined regeneration response to conifer removal treatments (Jones et al. 2005, Shepperd et al. 2006), simulated browsing (Jones et al. 2009), and white fir competition (Pierce and Taylor
2010). To date, no inventories or studies in California have assessed the impacts of native insects
and diseases to aspen health or their responses to various restoration treatments.

Daniel R. Cluck is a forest entomologist with the U.S. Forest Service. Here is a link to the full report.

With a change in weather coming this week, autumn colors may quickly fade.