Gap Analysis of Conserved Genetic Resources for Forest Trees

Gap Analysis of Conserved Genetic Resources for Forest Trees SARA R. LIPOW,∗†† KENNETH VANCE-BORLAND,∗ J. BRADLEY ST. CLAIR,† JAN HENDERSON,‡ AND CINDY MCCAIN§ ∗Department of Forest Science, Oregon State University, Corvallis, OR 97331, U.S.A. †U.S. Forest Service, Forestry Sciences Laboratory, Corvallis, OR 97331, U.S.A. ‡U.S. Forest Service, Supervisor’s Office, Mt. Baker–Snoqualmie National Forest, Mountlake Terrace, WA 98043, U.S.A. §U.S. Forest Service, Siuslaw National Forest, Corvallis, OR 97339, U.S.A. Abstract: We 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.). We developed geographic information system layers that detail 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. We 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. Análisis de Claros de Recursos Genéticos Conservados para Arboles´ de Bosque Resumen: Desarrollamos un método de analisis´ de claros para evaluar si los recursos genéticos conservados in situ en areas´ protegidas son adecuados para con´ıferas en el oeste de Oregon y Washington (E. U. A.). Desarrollamos capas de sistema de informacion´ geografica´ que detallan la localizacion´ de areas´ protegidas y la distribucion´ y abundancia de cada especie de arbol´ (Abies procera Rehd. y Pseudotsuga menzeisii Mirb). La distribucion´ y abundancia fueron inferidas a partir de datos espaciales disponibles que muestran la vegetacion´ potencial modelada y la vegetacion´ existente. Estratificamos la distribucion´ de cada especie en unidades para el analisis´ genético utilizando zonas de semillas y reproduccion´ y ecoregiones. La mayor´ıa de los estratos conten´ıan por los menos 5000 individuos en edad reproductiva en areas´ protegidas, lo que indica que los recursos genéticos estaban bien protegidos in situ en casi toda la region´ de estudio. Sin embargo, la proteccion´ in situ estricta estaba limitada para A. procera en las Colinas Willapa del suroeste de Washington. Se podr´ıa decir que ocurrio´ un claro de recursos genéticos in situ para P. menzeisii en las tierras bajas del sur de Puget, pero este claro fue llenado por recursos genéticos extensivos ex situ de la misma region.´ Encontramos que el método de analisis´ de claros es una herramienta valiosa para evaluar los recursos genéticos de arboles ´ de bosque en una region´ amplia. ††Current address: 2600 State Street, Oregon Department of Forestry, Salem, OR 97310, U.S.A., email [email protected] Paper submitted February 19, 2002; revised manuscript accepted July 29, 2003. 412 Conservation Biology, Pages 412–423 Volume 18, No. 2, April 2004 Lipow et al. Genetic Gap Analysis for Forest Trees 413 Introduction fir and Douglas-fir, respectively. These ex situ collections are a valuable component of the total available genetic Biological diversity refers to the variety and abundance of resources for the species. species and the communities in which they occur and to The goal of our in situ analysis was to identify places the genetic composition of individual species. Land-use where large populations of each species are protected changes, disease conditions, and climatic change directly in reserves and places where few or no trees are pro threaten forest species and communities. They also jeop tected (gaps). We did this by performing a gap analysis ardize the genetic variation that enables tree species to in a geographic information system (GIS). Gap analysis evolve and thrive under changing environmental condi typically refers to a scientific process that identifies the tions. Threats to tree species can affect the long-term sur degree to which native species and natural communities vival of the associated flora and fauna. Genetic variation are represented in present-day conservation lands (Scott of forest trees is also essential for sustainable production & Jennings 1997). Those species and communities not ad of forest products and therefore has important social and equately represented in the existing network of conserva economic implications. tion lands constitute conservation “gaps.” The methods Concerns for biological diversity and the genetic as of gap analysis were originally developed for application pects of sustainable forest management prompted a group to vertebrate species and land-cover types (Scott & Jen of public and private organizations in western Oregon and nings 1998), but they are relevant to a wide range of taxa Washington to form the Pacific Northwest Forest Tree and hierarchies of biodiversity. We applied them to de Gene Conservation Group. One objective of this group is termine whether the genetic variation within species is to identify whether areas in the region exist where addi adequately represented. Gap analysis involves intersect tional conservation measures are necessary to ensure that ing digital maps displaying protected areas with those the adaptation and evolutionary potential of important showing species occurrences and, in this case, patterns tree species are maintained. To identify possible areas, of genetic variation. we have compiled data on genetic resources conserved both at their original location (in situ) and at some other location (ex situ). Methods We developed a gap analysis approach to investigate ge netic resources conserved in situ in protected areas. We Study Area present results for Douglas-fir (Pseudotsuga menziesii The study area included a wide region extending from [Mirb.] Franco var. menziesii) and noble fir (Abies pro the coast of Oregon and Washington through the eastern cera Rehd.). Results for six other tree species are reported slopes and foothills of the Cascades (Fig. 1). Douglas-fir separately: Tsuga heterophylla (Raf.) Sarg., Thuja plicata occurs throughout much of the study area. Noble fir is Donn ex D. Don, Pinus ponderosa Dougl. ex Laws, Picea found from the Cascades of northern Washington to the sitchensis (Bong.) Carr., Pinus monticola Dougl. ex D. McKenzie River Valley in Oregon and at high peaks in Don, and Pinus lambertiana Dougl. (S.R.L., K.V.-B., J.B.S., the Coast Range and Willapa Hills (Fig. 2a). South of the J.A.H., & C.M., unpublished data). These species are com McKenzie River, noble fir overlaps the range and intro mon in western Oregon and Washington (U.S.A.) and are gresses with Shasta red fir (Abies magnifica shastensis commercially important. Lemm.) (Sorenson et al. 1990). The in situ genetic resources we evaluated are only one component of an overall gene conservation strat Protected Areas egy (Yanchuk & Lester 1996; Lipow et al. 2001). The tree species also have extensive genetic resources in ex We projected all GIS coverages and grids (Table 1) in Uni situ collections, including progeny tests, seed orchards, versal Transverse Mercator Projection, Zone 10. Analyses and seed stores (Lipow et al. 2001; S.R.L., K.V.-B., J.B.S., were done with ARC/INFO and Arcview software (Envi J.A.H., & C.M., unpublished data). In Oregon and Wash ronmental Systems Research Institute 1999, 2000). ington, progeny from >1679 noble fir selections from A protected-areas coverage was developed following natural populations are maintained in genetic tests or conventions employed by the National Gap Analysis Pro in 1 of 14 seed orchards. The tested selections span gram (GAP). This program assigns land to four status levels the species’ range, excluding the Willapa Hills of south (Scott et al. 1993). We considered all status 1 and 2 lands western Washington. Hundreds of additional selections protected. Management plans for status 1 lands call for are maintained in Europe. For Douglas-fir, over 1 million maintaining a natural state and allowing natural distur progeny from >29,000 selections are maintained in re bance events to proceed; examples include wilderness gional first-generation progeny tests. Second-generation areas, national parks, and U.S. Forest Service (USFS) re tests will contain >2000 of the selections evaluated in search natural areas. Status 2 lands are generally managed the first-generation tests. Regional seed stores include for natural values but may be used in ways that degrade >1460 and >20,000 seed lots stored by family for noble the quality of existing natural communities; examples Conservation Biology Volume 18, No. 2, April 2004 414 Genetic Gap Analysis for Forest Trees Lipow et al. The protected-areas coverage combined data from sev eral available coverages (Table 1; Fig. 3). In Oregon most status 1 and 2 lands were identified on the land manage ment and stewardship coverage (Oregon GAP). Most pro tected areas in Washington were identified on the major public lands coverage (Washington Department of Nat ural Resources) or the natural areas coverage (Interior Columbia Basin Ecosystem Management Project). We fol lowed the Oregon GAP land designations when assign ing reserve status to these lands. For example, because the Oregon GAP designated wilderness areas as status 1, we assigned them to status 1 in Washington. Preserves of The Nature Conservancy and natural-area preserves and natural-resource conservation areas of the Wash ington Department of Natural Resources were also in cluded as status 1 lands.

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