Canadian Forest Service Publications
Unusual drought symptoms in Douglas-fir. 1970. McMinn, R.G.; Funk, A. Canadian Journal of Botany 48(12): 2123-2127.
Issued by: Pacific Forestry Centre
Catalog ID: 19759
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Defoliation of the mid crown of Douglas-fir trees on Vancouver Island followed the hot, dry summer of 1967. Reddening of foliage in a similar mid crown position occurred on other trees in the spring of 1968. The position of these effects could not be attributed to localized fungus infections, insects, or microclimatic influences. A differential response to moisture stress by affected tissues is thought to have caused the unusual patterns. Other effects are also described.