Seed Zones Home Seed Zone Data
Following are details on seed zone layers based on empirical common garden datasets. .
Blue wildrye (Elymus glaucus):(Blue Mountains Ecoregion-Oregon, WA). Source-related phenotypic variance was investigated in a common garden study of populations of Elymus glaucus Buckley (blue wildrye) from the Blue Mountain Ecological Province of northeastern Oregon and adjoining Washington. The primary objective of this study was to assess geographic patterns of potentially adaptive differentiation in this self-fertile allotetraploid grass, and use this information to develop a framework for guiding seed movement and preserving adaptive patterns of genetic variation in ongoing restoration work. Progeny of 188 families were grown for 3 years under two moisture treatments and measured for a wide range of traits involving growth, morphology, fecundity, and phenology. Variation among seed sources was analyzed in relation to physiographic and climatic trends, and to various spatial stratifications such as ecoregions, watersheds, edaphic classifications, etc. Principal component (PC) analysis extracted four primary PCs that together accounted for 67% of the variance in measured traits. Regression and cluster analyses revealed predominantly ecotypic or stepped-clinal distribution of genetic variation. Three distinct geographic groups of locations accounted for over 84% of the variation in PC-1 and PC-2 scores; group differences were best described by longitude and ecoregion. Clinal variation in PC-3 and PC-4 scores was present in the largest geographic group. Four geographic subdivisions were proposed for delimiting E. glaucus seed transfer in the Blue Mountains.
Blue wildrye seed zone data
Basin wildrye (Leymus cinereus):(Columbia Basin - Great Basin). 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 both ploidy type and genetic variation within ploidy were observed in phenology, morphology, and production traits on 57 octoploid and 52 tetraploid basin wildrye from the intermountain Western U.S. (P<0.01). Octoploids had larger leaves, longer culms, and greater crown circumference than tetraploids but the numerical ranges of plant traits and their source climates overlapped between ploidy types. Still, among populations octoploids often had greater genetic variation for traits and occupied more diverse climates than tetraploids. Genetic variation for both ploidy types was linked to source climates in canonical correlation analysis, with the first two variates explaining 70%of the variation. Regression of those canonical variates with seed source climate variables produced models that explained 64% and 38%of the variation, respectively, and were used to map 15 seed zones covering 673258 km2. Utilization of these seed zones will help ensure restoration with adaptive seed sources for both ploidy types. The link between genetic traits and seed source climates suggests climate driven natural selection and adaptive evolution in basin wildrye. The more diverse climates occupied by octoploids and higher trait variation suggests a higher capacity for ecological differentiation than tetraploids in the intermountain Western U.S.
Basin wildrye seed zone data
Mountain Brome (Bromus carinatus): (Blue Mountains Ecoregion-Oregon, WA). Plants from 148 Blue Mountain seed source locations were evaluated in common-garden studies at two contrasting test sites. Data on phenology, morphology, and production were collected over two growing seasons. Plant traits varied significantly and were frequently correlated with annual precipitation and annual maximum temperature at seed source locations (P < 0.05). Plants from warmer locations generally had higher dry matter production, longer leaves, wider crowns, denser foliage, and greater plant height than those from cooler locations. Regression models of environmental variables with the first two principal components (PC 1 and PC 2) explained 46% and 40% of the total variation, respectively. Maps of PC 1 and PC 2 generally corresponded to elevation, temperature, and precipitation gradients. The regression models developed from PC 1 and PC 2 and environmental variableswere used to map seed transfer zones.
Mountain Brome seed zone data
Prairie junegrass (Koelaria macrantha): (coming soon)
Prairie junegrass seed zone data
Bluebunch wheatgrass (Pseudoroegneria spicata): A genecological approach was used to explore genetic variation in adaptive traits in Pseudoroegneria spicata, a key restoration grass, in the intermountain western United States. Common garden experiments were established at three contrasting sites with seedlings from two maternal parents from each of 114 populations along with five commercial releases commonly used in restoration. Traits associated with size, flowering phenology, and leaf width varied considerably among populations and were moderately correlated with the climates of the seed sources. Pseudoroegneria spicata populations from warm, arid source environments were smaller with earlier phenology and had relatively narrow leaves than those from mild climates with cool summers, warm winters, low seasonal temperature differentials, high precipitation, and low aridity. Later phenology was generally associated with populations from colder climates. Releases were larger and more fecund than most of the native ecotypes, but were similar to native populations near their source of origin. Differences among native populations associated with source climates that are logical for survival, growth, and reproduction indicate that genetic variation across the landscape is adaptive and should be considered during restoration. Results were used to delineate seed transfer zones and population movement guidelines to ensure adapted plant materials for restoration activities.
Bluebunch wheatgrass seed zone data
Sandberg's bluegrass (Poa secunda): Genetic variation for potentially adaptive traits of the key restoration species Sandberg bluegrass (Poa secunda J. Presl) was assessed over the intermountain western United States in relation to source population climate. Common gardens were established at two intermountain west sites with progeny from two maternal parents from each of 130 wild populations. Data were collected over 2 years at each site on fifteen plant traits associated with production, phenology, and morphology. Analyses of variance revealed strong population differences for all plant traits (P < 0.0001), indicating genetic variation. Both the canonical correlation and linear correlation established associations between source populations and climate variability. Populations from warmer, more arid climates had generally lower dry weight, earlier phenology, and smaller, narrower leaves than those from cooler, moister climates. The first three canonical variates were regressed with climate variables resulting in significant models (P < 0.0001) used to map 12 seed zones. Of the 700 981 km2 mapped, four seed zones represented 92% of the area in typically semi-arid and arid regions. The association of genetic variation with source climates in the intermountain west suggested climate driven natural selection and evolution. We recommend seed transfer zones and population movement guidelines to enhance adaptation and diversity for large-scale restoration projects.
Sandberg's bluegrass seed zone data
Indian ricegrass (Achnatherum hymenoides): (Colorado Plateau and Great Basin) Indian ricegrass (Achnatherum hymenoides [Roemer & J.A. Schultes] Barkworth) is a widely distributed, highly desirable native species in desert ecosystems in the western United States. Yet there are no studies linking genetic variation in Indian ricegrass with climate across major areas of its natural distribution. In this study, seeds from 106 collection locations from the southwestern United States were established in common gardens and four phenological traits (Phen; such as blooming date), six production traits (Pro; such as dry weight), and eight morphology traits (Morph; such as leaf dimensions) were measured in 2007 and 2008. Analyses of variance revealed that all basic garden traits differed among source locations (P,0.01), indicating widespread genetic variation. Within Phen, Pro, and Morph categories, canonical correlation was completed between basic garden traits and source location temperature and precipitation. This resulted in six significant (P,0.01) canonical variates (Phen 1, Pro 1 and 2, and Morph 1, 2, and 3) representing each category of traits. Linear correlations (r.60.25, P,0.01) consistently linked monthly temperature at collection locations with Phen 1, Pro 1, and Morph 1. For precipitation, however, correlations were more dependent on month, with the strongest correlations during the spring developmental period. Using regression models between traits and climate, a map with 12 seed zones was developed representing much of the southwestern United States. This generally distinguished genetic variation between cooler and warmer regions, usually separating more northern, higher elevation areas from more southern, lower elevation areas. The correspondence between climate and genetic variation suggested climate-driven differences in natural selection, likely leading to adaptation. The seed zone map is recommended to guide and broaden germplasm collection and utilization for Indian ricegrass restoration.
Indian ricegrass seed zone data
Tapertip onion (Allium acuminatum): The choice of germplasm is critical for sustainable restoration, yet seed transfer guidelines are lacking for all but a few herbaceous species. Seed transfer zones based on genetic variability and climate were developed using tapertip onion (Allium acuminatum Hook.) collected in the U.S. Great Basin and surrounding areas. Bulbs from 53 locations were established at two common garden sites and morphological (such as leaf and scape dimensions), phenological (such as bolting date and flowering), and production traits (such as emergence and seeds per plant) were measured. Differences among source locations for plant traits within both common gardens were strong (P<0.001) indicating genetic variation. Principal component 1 (PC 1) for phenological traits, with R2=0.59, and PC 1 for production traits, with R2 =0.65, were consistently correlated with annual, maximum, minimum, and average temperature, annual precipitation, and frost free days at source locations (P<0.05). Regression of PC 1 phenology and PC 1 production scores with source location climates resulted in models with R2 values of 0.73 and 0.52, respectively. Using GIS, maps of these models were overlaid to develop proposed seed zones to guide the choice of germplasm for conservation and restoration of Tapertip onion across the collection region.
Tapertip onion seed zone data
Oceanspray (Holodiscus discolor): (Western Oregon and Washington) This common garden study was implemented to characterize the variability in growth and phenological traits relative to climatic and geographic variables of 39 Holodiscus discolor (Pursh) Maxim. accessions from locations throughout the Pacific Northwest, U.S.A. Principal component analysis of 12 growth and phenological traits explained 48.2% of the observed variability in the first principal component (PC-1). With multiple regressions, PC-1 was compared to environmental values at each source location. Regression analysis identified a four-variable model containing elevation, minimum January temperature, maximum October temperature, and February precipitation that explained 86% of the variability in PC-1 (r2 ¼ 0.86, p < 0.0001). Spatial analysis using this regression model identified patterns of genetic diversity within the Pacific Northwest that can help guide germplasm selection (i.e., seed collections) for restoration and revegetation activities.
Oceanspray seed zone data
References:
Bower, A., St. Clair J.B., and V.J. Erickson. 2014. Generalized provisional seed zones for native plants. Ecological Applications 24(5): 913-919.
Cathey, H.M. 1990. USDA Plant hardiness zone map. Washington, D.C.: U.S. Department of Agriculture. USDA miscellaneous publication No. 1475. Available at http://www.usna.usda.gov/Hardzone/ushzmap.html.
Campbell, R. K. 1986. Mapped genetic variation of Douglas-fir to guide seed transfer in southwest Oregon. Silvae Genet. 35:85-96.
Erickson, V.J., Mandel, N.L. and F.C Sorenson. 2004. Landscape patterns of phenotypic variation and population structuring in a selfing grass, Elymus glaucus (Blue wildrye). Can. J. Bot. 82:1776-1789.
Johnson, G.R., F.C Sorenson, J.B. St Clair and R.C. Cronn. 2004. Pacific northwest forest tree seed zones - A template for native plants?. Native Plants 5:131-140.
Johnson, G.R , L. Stritch, P. Olwell, S. Lambert, M.E. Horning, and R. Cronn. 2010. What are the best seed sources for ecosystem restoration on BLM and USFS lands? Native Plants 11: 117-131
Johnson, R.C., V.J. Erickson, N.L. Mandel, J.B. St Clair, and K.W. Vance-Borland. 2010. Mapping genetic variation and seed zones for Bromus carinatus in the Blue Mountains of Eastern Oregon, U.S.A. Botany 88:(2010) 725-736.
Johnson, R.C., M.E. Horning, E.K. Espeland and K.W. Vance-Borland. 2014. Relating adaptive genetic traits to climate for Sandberg bluegrass from the intermountain western United States. Evolutionary Applications 8(2015): 172-184.
Omernik, J.M. 1987. Ecoregions of the conterminous United States. Ann. Assoc. Amer. Geogr. 77(1): 118-125. doi:10.1111/j.1467-8306.1987.tb00149.x.
