Yellow Cedar Vulnerable to Spring Cold
In a further attempt to unravel the mystery of what is killing yellow cedar in southeast Alaska, scientists have turned to climate change as a possible culprit.
Disease and insects were previously eliminated as perpetrators.
This research uncovered new clues by showing that cold tolerance in yellow cedars, particularly those growing below 130 m, declines much earlier in spring and to a greater extent, compared with their more vigorous co-habitants, western hemlock.
By early May, cedar tolerates temperatures down to -11 C, compared with about -14 C for hemlock. This makes yellow cedar more susceptible to cold snaps following an early spring thaw, conditions expected to occur more often amid climatic warming. These results are consistent with some aspects of the mortality pattern experienced here by yellow cedar.
Paul G. Schaberg, Paul E. Hennon, David V. D'Amore, Gary J. Hawley and Catherine H. Borer. 2005. Seasonal differences in freezing tolerance of yellow-cedar and western hemlock trees at a site affected by yellow-cedar decline. Canadian Journal of Forest Research. 35(8): 2065-2070.