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October 10, 2025

Emergence and Mortality of Douglas-Fir, Western Hemlock, and Western Redcedar Seedlings

Key Points

Douglas-fir showed an average first-year mortality rate of 82%, largely due to animal factors and weather.
Western hemlock experienced a 97% first-year mortality rate, primarily caused by weather conditions and disease.
Western redcedar also faced significant mortality at 95%, with weather being the major factor affecting survival.
Most seedlings emerged in the spring, specifically between April 15 and May 15, indicating seasonal patterns.

Abstract

Abstract Emergence of natural seedlings on the H. J. Andrews Experimental Forest in west-central Oregon between 1956 and 1967 was irregular from year to year; but most seedlings appeared between April 15 and May 15. Average percentage of first-year mortality was: Douglas-fir 82, western hemlock 97, and western redcedar 95. Major causes of first-year mortality, in percent, were: Douglas-fir—animal 58, weather 27, and disease 6; hemlock—weather 58, disease 21, and animal 11; redcedar—weather 80, animal 8, and disease 2. Cumulative losses of Douglas-fir seedlings, in percent, were: 1 year 83, 2 years 86, 3 years 86, 4 years 88, 5 years 88, and 6 years 89. Seedling protection might be most productive if directed toward animals for Douglas-fir and toward weather for hemlock and redcedar. Forest Sci. 17:230-237.

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