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  1. Nuclear genetic variation across the range of ponderosa pine (Pinus ponderosa): Phylogeographic, taxonomic and conservation implications

    Ponderosa pine (Pinus ponderosa) is among the most broadly distributed conifer species of western North America, where it possesses considerable ecological, esthetic, and commercial value. It exhibits complicated patterns of morphological and genetic variation, suggesting that it may be in the process of differentiating into distinct regional...

    Author(s):
    Kevin M. Potter; Valerie D. Hipkins; Mary F. Mahalovich; Robert E. Means
    Year:
    2015
    Keywords:
    Biogeography . Gene conservation . Inbreeding . Isozymes . Microevolution . Microsatellites
    Source:
    Tree Genetics & Genomes (2015) 11:38

  2. Levels of genetic variation in trees: influence of life history characteristics

    In a previous study, levels of genetic variation, as measured by isozyme analyses, were compared for 113 taxa of vascular plants. Each species was classified for 12 life history and ecological traits and three measures of genetic variation were calculated. Plants with large ranges, high fecundities, an outcrossing mode of reproduction, wind pollination, a long...

    Author(s):
    J. L Hamrick; J. B. Milton; Y. B. Linhart
    Year:
    1981
    Keywords:
    Source:
    Gen. Tech. Rep. PSW-GTR-48. Berkeley, CA: Pacific Southwest Forest and Range Exp. Stn, Forest Service, U.S. Department of Agriculture: p. 35-41

  3. Genetic variation in California oaks

    In forestry the importance of genetic variation for successful reproduction, survival and growth has been widely documented for commercial conifers; until recently, little genetic work has been done on the California oaks. Even before the nature of genetic variation was scientifically investigated, its importance was suspected in operational forestry. Many failures of...

    Author(s):
    Constance I. Millar; Diane L. Delany; Lawrence A. Riggs
    Year:
    1990
    Keywords:
    Source:
    Fremontia 18(3):20-21

  4. Conservation genetics of bull trout: Geographic distribution of variation at microsatellite loci.

    We describe the genetic population structure of 65 bull trout (Salvelinus confluentus) populations from the northwestern United States using four microsatellite loci. The distribution of genetic variation as measured by microsatellites is consistent with previous allozyme and mitochondrial DNA analysis. There is relatively little genetic variation...

    Author(s):
    P. Spruell; A.R. Hemmingsen; P.J. Howell; N. Kanda; F.W. Allendorf
    Year:
    2003
    Keywords:
    Source:
    Conservation Genetics. 4: 17-29

  5. Genetic variation in tree structure and its relation to size in Douglas-fir: II. crown form, branch characters, and foliage characters.

    Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found for relative crown width; stem increment per crown projection area; leaf...

    Author(s):
    J.B. St. Clair
    Year:
    1994
    Keywords:
    Source:
    Canadian Journal of Forest Research. 24: 1236-1247

  6. Genetic differentiation among populations of Pinus ponderosa from the upper Colorado River Basin

    Genetic variation among 62 populations of ponderosa pine was studied by comparing seedlings from all populations according to (1) growth and development of 4-yr-old seedlings in three disparate common gardens and (2) patterns of shoot elongation of 2-yr-old seedlings in a greenhouse. Genetic variation was detected among populations for 19 of the variables, most of...

    Author(s):
    Gerald Rehfeldt
    Year:
    1990
    Keywords:
    genetic variation, Pinus ponderosa, upper Colorado River Basin
    Source:
    Botanical Gazette. 151(1):125-137.

  7. A model of genetic variation for Pinus ponderosa in the Inland Northwest (U.S.A.): applications in gene resource management

    Models were developed to describe genetic variation among 201 seedling populations of Pinus ponderosa var. ponderosa in the Inland Northwest of the United States. Common-garden studies provided three variables Jhat reflected growth and development in field environments and three principal components of six variables that reflected patterns of shoot elongation....

    Author(s):
    Gerald Rehfeldt
    Year:
    1991
    Keywords:
    Pinus ponderosa, Inland Northwest
    Source:
    Canadian Journal of Forest Research. 21: 1491-1500.

  8. Indicator 1.07. Number and geographic distribution of forest-associated species at risk of losing genetic variation and locally adapted genotypes

    This indicator provides information on the number and distribution of forest-associated species at risk of losing genetic variation across their geographic range. Comparing a species' current geographic distribution with its historic distribution is the basis for identifying those species whose range has contracted significantly. Human activities are accelerating...

    Author(s):
    C. H. Flather; M. S Knowles; C. H. Sieg
    Year:
    2011
    Keywords:
    indicator, species, at-risk, genetic variation, geographic range
    Source:
    In: National report on sustainable forests - 2010. FS-979. Washington, DC: U.S. Department of Agriculture, Forest Service: II-27-II-29.

  9. Incorporating latitudinal and central–marginal trends in assessing genetic variation across species ranges

    The genetic variation across a species’ range is an important factor in speciation and conservation, yet searching for general patterns and underlying causes remains challenging. While the majority of comparisons between central and marginal populations have revealed a general central–marginal (C-M) decline in genetic diversity, others show no clear pattern. Similarly...

    Author(s):
    Qinfeng Guo
    Year:
    2012
    Keywords:
    α-, β- and γ-diversity, climate change, genetic diversity, history, novelty, phylogeography, range geometry and orientation, species invasion
    Source:
    Molecular Ecology 21:5396–5403

  10. Collecting genetic variation on a small island

    Genetic variation is the most powerful factor in ensuring the long term success of trees and forests in times of change. In order to protect against loss of genetic variation from threats, including pests and diseases and climate change, the Royal Botanic Gardens, Kew, is developing a national tree seed collection for the United Kingdom.
    This paper...

    Author(s):
    S. Kallow; C. Trivedi
    Year:
    2017
    Keywords:
    Source:
    In: Sniezko, Richard A.; Man, Gary; Hipkins, Valerie; Woeste, Keith; Gwaze, David; Kliejunas, John T.; McTeague, Brianna A., tech. cords. 2017. Gene conservation of tree species—banking on the future. Proceedings of a workshop. Gen. Tech. Rep. PNW-GTR-963. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 129-136.

  11. Assessing temporal genetic variation in a cougar population: Influence of harvest and neighboring populations

    The geography of the Black Hills region of South Dakota and Wyoming may limit connectivity for many species. For species with large energetic demands and large home ranges or species at low densities this can create viability concerns. Carnivores in this region, such as cougars (Puma concolor), have the additive effect of natural and human-induced mortality;...

    Author(s):
    Rebeca L. Juarez; Michael K. Schwartz; Kristine L. Pilgrim; Daniel J. Thompson; Stephanie A. Tucker; Joshua B. Smith; Jonathan A. Jenks
    Year:
    2016
    Keywords:
    cougar, genetic variation, Black Hills, harvest, South Dakota, microsatellite
    Source:
    Conservation Genetics. 17: 379-388.

  12. The timing of flowering in Douglas-fir is determined by cool-season temperatures and genetic variation

    Trees have evolved to time flowering to maximize outcrossing, minimize exposure to damaging frosts, and synchronize development with soil moisture and nutrient availability. Understanding the environmental cues that influence the timing of reproductive budburst will be important for predicting how flowering phenology of trees will change with a changing climate, and...

    Author(s):
    Janet S. Prevey; Constance A. Harrington; J. Bradley St. Clair
    Year:
    2018
    Keywords:
    Climate change, Pseudotsuga menziesii, reproductive budburst, seed orchards, tree phenology.
    Source:
    Forest Ecology and Management. 409: 729-739.

  13. Linking genetic variation in adaptive plant traits to climate in tetraploid and octoploid basin wildrye [Leymus cinereus (Scribn. & Merr.) A. Love] in the western U.S.

    Few studies have assessed how ploidy type within a species affects genetic variation among populations in relation to source climates. Basin wildrye (Leymus cinereus (Scribn. & Merr.) A. Love) is a large bunchgrass common in the intermountain Western U.S. found in both octoploid and tetraploid types. In common gardens at two sites over two years differences in...

    Author(s):
    R. C. Johnson; K. Vance-Borland
    Year:
    2016
    Keywords:
    climate, basin wildlrye, Leymus cinereus, population
    Source:
    PLoS ONE. 11: e0148982.

  14. Genetic variation and seed zones of Douglas-fir in the Siskiyou National Forest.

    Provisional seed zones and breeding zones were developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Siskiyou National Forest in southwestern Oregon. Zones were based on maps of genetic variation patterns obtained by evaluating genotypes of trees from 260 locations in the region. Genotypes controlling growth vigor and growth...

    Author(s):
    Robert K. Campbell; Albert I. Sugano
    Year:
    1993
    Keywords:
    Pseudotsuga menziesii, geographic genetic variation, adaptation, ecological genetics, genecology
    Source:
    Res. Pap. PNW-RP-461. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 23 p

  15. Genetic Variation in Seed and Fruit Characters in Sugar Maple

    A study of the seeds and fruits of sugar maples from 32 provenances has shown that: (1) dry weight of seed and percentage of filled fruit varied genetically among and within provenances; (2) dry weight of seed and latitude of provenance are positively correlated; provenances from higher latitudes and colder temperatures exhibited higher weights; (3) the percentage of...

    Author(s):
    William J. Gabriel
    Year:
    1978
    Keywords:
    Source:
    Res. Pap. NE-404. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 4p.

  16. Genetic variation and seed transfer guidelines for ponderosa pine in central Oregon.

    Adaptive genetic variation in seed and seedling traits for ponderosa pine from the east slopes of the Cascade Range in Oregon was analyzed by using 307 families from 227 locations. Factor scores from three principal components based on seed and seedling traits were related by multiple regression to latitude, distance from the Cascade crest, elevation, slope, and...

    Author(s):
    Frank C. Sorensen
    Year:
    1994
    Keywords:
    Pinus ponderosa, seedlings, provenance, geographic genetic variation, ecological genetics, genecology, genetic diveristy
    Source:
    Res. Pap. PNW-RP-472. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 24 p

  17. Genetic variation and seed transfer guidelines for ponderosa pine in the Ochoco and Malheur National Forests of central Oregon.

    Adaptive genetic variation in seed and seedling traits was evaluated for 280 families from 220 locations. Factor scores from three principal components were related by multiple regression to latitude, longitude, elevation, slope, and aspect of the seed source, and by classification analysis to seed zone and elevation band in seed zone. Location variance was significant...

    Author(s):
    Frank C. Sorensen; John C. Weber
    Year:
    1994
    Keywords:
    Pinus ponderosa, seedlings, breeding zones, provenance, genetic variation, adaptive variation, genetic diversity
    Source:
    Res. Pap. PNW-RP-468. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 30 p

  18. Genetic variation in tolerance of Douglas-fir to Swiss needle cast as assessed by symptom expression.

    The incidence of Swiss needle cast on Douglas-fir has increased significantly in recent years on the Oregon coast. Genetic variation in symptoms of disease infection, as measured by foliage traits, was assessed in two series of progeny trials to determine whether these "crown health" indicators were under genetic control and correlated with tolerance;...

    Author(s):
    G.R. Jonhson
    Year:
    2002
    Keywords:
    resistance, Phaeocryptopus gaeumannii, Pseudotsuga menziesii, genetic gain
    Source:
    Silvae Genetica. 51(2-3): 80-88

  19. Population genetic analysis of Bromus tectorum (Poaceae) indicates recent range expansion may be facilitated by specialist genotypes

    The mechanisms for range expansion in invasive species depend on how genetic variation is structured in the introduced range. This study examined neutral genetic variation in the invasive annual grass Bromus tectorum in the Intermountain Western United States. Patterns of microsatellite (SSR) genotype distribution in this highly inbreeding species were used to make...

    Author(s):
    Keith R. Merrill; Susan E. Meyer; Craig E. Coleman
    Year:
    2012
    Keywords:
    Bromus tectorum, cheatgrass, downy brome, ecological genetics, inbreeding, invasive species, local adaptation, microsatellite, Poaceae
    Source:
    American Journal of Botany. 99(3): 529-537.

  20. Climate-related genetic variation in drought-resistance of Douglas-fir ( Pseudotsuga menziesii )

    There is a general assumption that intraspecific populations originating from relatively arid climates will be better adapted to cope with the expected increase in drought from climate change. For ecologically and economically important species, more comprehensive, genecological studies that utilize large distributions of populations and direct measures of traits...

    Author(s):
    Sheel Bansal; Constance A. Harrington; Peter J. Gould; J. Bradley St.Clair
    Year:
    2014
    Keywords:
    climate change, genecology, minimum conductance, specific leaf area, water deficit
    Source:
    Global Change Biology

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