Canadian Forest Service Publications

Exotic pathogens, resistant seed and restoration of forest tree species in western North America. 2004. Sniezko, R.; Tomback, D.; Rochefort, R.M.; Goheen, E.M.; Hunt, R.S.; Beatty, J.S.; Murray, M.; Betlejewski, F. Pages 21-26 in In Proceedings of the Second Conference on Klamath-Siskiyou Ecology. Siskiyou Field Institute, Cave Junction, OR.

Year: 2004

Available from: Pacific Forestry Centre

Catalog ID: 32487

Language: English

CFS Availability: PDF (download)


Non-native invasive pathogens such as white pine blister rust (Cronartium ribicola) and Port-Orford-cedar root disease (Phytophthora lateralis) are killing trees and disrupting forest ecosystems in western North America. Populations of western white pine (Pinus monticola), sugar pine (P. lambertiana), whitebark pine (P. albicaulis), and limber pine (P. flexilis) are declining precipitously from damage by blister rust. Foxtail pine (Pinus balfouriana) and southwestern white pine (P. stobiformis) populations are also infected by blister rust in parts of their range. Phytophthora lateralis continues to spread and kill Port-Orford-cedar (Chamaecyparis lawsoniana) in Oregon and California. Because resistant individuals in all these species are rare, genetic variation may be reduced to the point where future populations may not be viable without active management. Seeds from resistant parents are now available for western white pine, sugar pine, and Port-Orford-cedar restoration for some areas. Selection and breeding programs for resistance, coupled with active ecological management, will be needed to create opportunities to restore and retain these species in forest ecosystems on federal or crown lands. Restoration strategies for maintaining these species on the landscape must include planting resistant stock and increasing any opportunities for natural regeneration until resistance characterizes populations, and they are able to continue to evolve in the continued presence of the pathogens. Scientists and the public will have difficult decisions to face regarding actions to take in wilderness areas and national parks.

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