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Abstract
True fir stands in California (3.5 million acres) were surveyed during 1979-1980 to estimate the prevalence of infection by
Heterobasidion annosum, and to determine stand and tree characteristics associated with the occurrence of annosus root disease. Approximately 4 percent (1.46 billion board-feet) of the live true firs were estimated to be infected by
H. annosum; dead firs associated with the fungus were estimated to be 25 percent (68 million board-feet) of the total dead firs during a 1.5-year period. Annosusroot disease was estimated to infest 18 percent of the surveyed area (632,000 acres), indicating a high prevalence in fir stands. The fungus occurred most often in pure fir stands, red fir stands, in stands where the basal area of live true fir exceeded 20 m2 per hectare, and in stands having patterns of chronic mortality. Larger, older trees, near stumps, had high rates of infection.
Parent Publication
Citation
Slaughter, G. W.; Parmeter Jr., J. R. 1989. Annosus Root Disease in True Firs in Northern and Central California National Forests. In: Otrosina, William J.; Scharpf, Robert F., technical coordinators. 1989. Proceedings of the symposium on research and management of annosus root disease (
Heterobasidion annosum) in western North America; April 18-21, 1989; Monterey, CA. Gen. Tech. Rep. PSW-GTR-116. Berkeley, CA: Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture; p. 70-77
