The yellow cedar (Callitropsis nootkatensis) was recently denied being listed as an endangered or threatened species under the Endangered Species Act.
A group petitioned the U.S. Fish and Wildlife Service on June 24th, 2014 when they became concerned about the widespread mortality of the yellow cedar.
The tree has been in decline since the late 1800s, but the reasons why weren’t known until recently. Biotic causes such as higher fungi, oocmycetes, insects, nematodes, viruses, mycoplasmas, and bears were ruled out. Several early studies noted that the decline occurred mainly on sites with saturated soil.
The yellow cedar has shallow fine roots, an adaptation for nutrient uptake. These fine roots are less cold hardy compared with roots of other species and tend to lose hardiness early in spring at relatively low temperatures. These adaptations allow the yellow cedar roots to begin taking up nutrients in early spring when the soil thaws, but make them vulnerable to damage if temperatures in the upper soil horizon drop below about -5°C.
Throughout much of the yellow cedar’s range in Alaska, the snow cover has been historically adequate to protect these shallow roots from freezing damage during periods of cold weather. Since the early 1900s early thaws and reduced snow cover have resulted in the mortality of the tree.
Early this month, the U.S. Fish and Wildlife Service released their findings and denied protection under the Endangered Species Act. They did note the decline of the species but said that only 6 percent of the species’ range is currently impacted.
“The species is expected to persist in thousands of stands across its range, in a variety of ecological niches, with no predicted decrease in overall genetic diversity into the foreseeable future.”