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Recent increases found in yellow-cedar in Alaska

Photo of Yellow-cedar (Callitropsis nootkatensis) in Cedar Bay, Alaska. Yellow-cedar (Callitropsis nootkatensis) in Cedar Bay, Alaska. Snapshot : In most unmanaged forests in Alaska, yellow-cedar has recently increased, as measured by live tree basal area, and the average mortality rate has been relatively low.

Principal Investigators(s) :
Barrett, Tara M. 
Research Location : Alaska
Research Station : Pacific Northwest Research Station (PNW)
Year : 2017
Highlight ID : 1368


Climate change is expected to impact forests worldwide, and yellow-cedar (Callitropsis nootkatensis) decline has been used as an example of how changing climate can impact a tree species. However, most previous research has not placed yellow-cedar decline within the overall context of yellow-cedar. The large numbers and wide geographic range of yellow-cedar trees in Alaska, and the recent (1995–2013) stability in the monitored population serve as important contextual information for yellow-cedar decline. This research also illustrates that understanding the spatial and temporal complexities of how tree species respond to climate change will be improved if focused studies are accompanied by regional monitoring. Tara Barrett, a research forester with the Forest Service’s Pacific Northwest Research Station, and her former colleague Robert Pattison, used a 2004–2013 regional inventory of the temperate rainforest of Alaska (671 plots with yellow-cedar) to estimate current attributes and a subset of 564 remeasured plots (established 1995–1998) to estimate recent change. Current attributes apply to about 98 percent of the yellow-cedar range in Alaska. Change estimates exclude national forest wilderness and apply to about 65 percent of yellow-cedar range in Alaska. Results show that in unmanaged forests, yellow-cedar live tree basal area recently (1995–1998 to 2004–2013) increased, with a 95 percent confidence interval of a 0.3 percent to 3.3 percent increase per decade. Yellow-cedar has a relatively low mortality rate, 0.41 percent of trees per year. An analysis of live tree to snag (standing dead or dying tree) ratios was consistent with elevated mortality of yellow-cedar prior to 1995 but also indicated that little range contraction had occurred.