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Individual Highlight

Scientists Find Cause of Yellow-cedar Death in Alaska's Coastal Forests

Yellow-cedar's shallow roots make it vulnerable to freezing injury in spring when snow is not present to provide insulation. Paul Hennon, Forest ServiceSnapshot : Absence of snow to protect shallow roots results in roots freezing and extensive tree death

Principal Investigators(s) :
Hennon, Paul 
Research Station : Pacific Northwest Research Station (PNW)
Year : 2012
Highlight ID : 75


Yellow-cedar decline has affected about 60 to 70 percent of trees in forests covering 600,000 acres in Alaska and British Columbia. The cause of this extensive tree death, called yellow-cedar decline, is now known to be a form of root freezing that occurs during cold weather in late winter and early spring when snow is not present on the ground to protect fine roots.

Yellow-cedar's shallow rooting, early spring growth, and unique vulnerability to freezing injury contribute to its decline in Alaska's coastal forests. The tree thrives in wet soils, but its tendency to produce shallow roots to access nitrogen on these sites makes it more vulnerable to fine root freezing when spring snow levels are reduced by a warmer climate. Yellow-cedar health depends on changing snow patterns, thus, locations for appropriate conservation and management activities need to follow the shifting snow patterns on the landscape.

Forest Service scientists synthesized 30 years of research and offer a conservation strategy framework for yellow-cedar in Alaska. The scientists are working with Federal land managers in Alaska to use this new information as the framework for a comprehensive conservation strategy for yellow-cedar in the context of a changing climate. Coastal Alaska is expected to experience less snow but will retain a persistence of periodic cold weather events in the future. Current and future yellow-cedar health can be predicted in landscapes based on observed patterns of snow and soil drainage.

Forest Service Partners

External Partners

  • Northern Research Station
  • USFS Alaska Region
  • Stanford University
  • University of Vermont

Program Areas