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Conservation of Forest Genetic Resources in the United States.

Published Aug 13, 2010


Douglas-fir (Pseudotsuga menziesii)

Researchers developed a gap analysis approach to evaluate whether the genetic resources conserved in situ in protected areas are adequate for conifers in Western Oregon and Washington (U.S.A.). Theydeveloped geographic information system layers that detailed the location of protected areas and the distribution and abundance of each tree species (noble fir [Abies procera Rehd.] and Douglas-fir [Pseudotsuga menzeisii Mirb.]). Distribution and abundance were inferred from available spatial data showing modeled potential and actual vegetation. They stratified the distribution of each species into units for genetic analysis using seed and breeding zones and ecoregions. Most strata contained at least 5000 reproductive-age individuals in protected areas, indicating that genetic resources were well protected in situ throughout most of the study region. Strict in situ protection was limited, however, for noble fir in the Willapa Hills of southwestern Washington. An in situ genetic resource gap arguably occurred for Douglas-fir in the southern Puget lowlands, but this gap was filled by extensive ex situ genetic resources from the same region. The gap analysis method was an effective tool for evaluating the genetic resources of forest trees across a large region.

The Result

The gap analysis done with ecoregions is intended to complement and add to the one done with seed zones. Ecoregions are widely used in Oregon and Washington for demarcating areas of similar environmental and ecological characteristics. They can serve as a surrogate for data on genetic structure if genetic structure is well correlated with environmental and ecological characteristics.

Another reason for running the gap analysis with ecoregions is that various U.S. federal and state agencies use them in conservation assessments. Their use should therefore facilitate the integration of these results with those from analyses of other ecosystem components.


Lipow, S. R., K. Vance-Borland, J. B. St. Clair, J. Henderson, and C. McCain, 2004, Gap Analysis of Conserved Genetic Resources for Forest Trees, Conservation Biology, Volume 18 Page 412 Retreived July 27, 2006 from <>.

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