Ex situ gene conservation for conifers in the Pacific Northwest.

Abstract

Recently, a group of public and private organizations responsible for managing much of the timberland in western Oregon and Washington formed the Pacific Northwest forest tree Gene Conservation Group (GCG) to ensure that the evolutionary potential of important regional tree species is maintained. The group is first compiling data to evaluate the genetic resource status of several species of conifers both at their original location (in situ) and at some other location (ex situ). We summarize the ex situ genetic resources present in seed orchards, provenance and progeny tests, seed stores, and clone banks both in western Oregon and Washington and in other countries with germplasm that originated in western Oregon and Washington. Some species, such as ponderosa pine (Pinus ponderosa Dougl. ex Laws.), noble fir (Abies procera Rehd.), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) are found to have extensive genetic resources in ex situ forms. The resources for western redcedar (Thuja plicata Donn ex D. Don), for example, are more limited. Disease greatly influenced the development of ex situ genetic resources for western white pine (P. monticola Dougl. ex D. Don), sugar pine (P. lambertiana Dougl.), and Sitka spruce (Picea sitchensis (Bong.). The summaries of genetic resources are, therefore, placed in the context of issues affecting each species. This provides land managers with the accurate information necessary for assessing the potential value of each resource for gene conservation and for prioritizing future actions.

Allozyme variation, differentiation, and inbreeding in populations ofPinus mugoin Bulgaria

“…Spatial genetic substructure and past extinctions and recolonizations have probably reduced the effective population sizes (N e ) in all studied populations to levels considerably lower than those expected in panmictic populations with the same number of trees (Whitlock and Barton 1997). Conservation efforts are often more critical for tree species growing under severe environmental conditions and having small fragmented populations than for species of interest for tree improvement (Yanchuk 2001;Lipow et al 2002). All P. mugo populations in the Rila and Pirin Mountains fall within national parks and are protected from logging by law.…”

Gap Analysis of Conserved Genetic Resources for Forest Trees

“…The in situ genetic resources we evaluated are only one component of an overall gene conservation strategy (Yanchuk & Lester 1996; Lipow et al 2001). The tree species also have extensive genetic resources in ex situ collections, including progeny tests, seed orchards, and seed stores (Lipow et al 2001; S.R.L., K.V.‐B., J.B.S., J.A.H., & C.M., unpublished data). In Oregon and Washington, progeny from >1679 noble fir selections from natural populations are maintained in genetic tests or in 1 of 14 seed orchards.…”