Session: Common Garden Studies & Seed Transfer Guidelines
Tuesday 2:00 p.m. - 5:00 p.m. Ballroom 1
Randy Johnson, Moderator
2:00 p.m.
Ecological genetics of Penstemon in the Great Basin
Andrea Kramer
Presentation (PDF)
Ecological genetics research was carried out multiple populations of three common forb species in the Great Basin (Penstemon deustus, P. pachyphyllus, and P. rostriflorus) to understand the interacting effects of geographic isolation, distance, topography, climate, and pollination syndrome on population genetic differentiation of each species. Research included microsatellite DNA analysis, common garden studies, and experimental crosses to test for inbreeding and outbreeding depression in different species and populations. Results revealed significant genetic diversity and divergence among populations in both neutral and potentially adaptive genetic traits for all three species, but there were striking differences in study results depending upon the primary pollinator of each species. The hummingbird-pollinated species had much greater gene flow among populations than the two bee-pollinated species, but this greater gene flow did not translate to lower divergence in quantitative traits. However, the first generation of experimental crosses spanning increasing geographic and genetic distances revealed both inbreeding and outbreeding depression in progeny of the bee-pollinated P. pachyphyllus, which had the highest degree of population divergence. No negative fitness effects were identified in first generation crosses of the hummingbird-pollinated P. rostriflorus. While additional research on these and similar species is urgently needed, these results provide insight into the development of seed transfer zones and can help guide the movement and mixing of seeds for different forb species being used in ecological restoration efforts.
Andrea Kramer has been in the role of Executive Director of Botanic Gardens Conservation International US since January 2008. In this role, she works on plant conservation, education, and outreach programs and is charged with connecting botanic gardens and partners in the United States with BGCI’s global plant conservation network and resources. Prior to joining BGCI, Andrea worked for 8 years in the conservation department at Chicago Botanic Garden. In her role as endangered plant specialist, she worked closely with numerous botanic garden partners to grow the Center for Plant Conservation’s National Collection of Endangered Plants. More recently, Andrea has worked with the Bureau of Land Management and science staff at Chicago Botanic Garden to research plant restoration practices in the western United States. She recently completed her Ph.D. at the University of Illinois at Chicago on the ecological genetics of Penstemon species in the Great Basin.
2:30 p.m.
Genecology and seed zones for native grasses and forbs
R.C. Johnson
Presentation (PDF)
Western landscapes are managed to a large extent for wildlife habitat, recreation, and grazing resources. However, urbanization, frequent fires and increasing pressure from invasive weeds are interacting to cause an unsustainable cycle of environmental degradation to plant communities and ecosystems. Restoration efforts that emphasize native germplasm adapted to “local” environments may be the best approach to ensure long-term sustainable management. Developing seed zones is a way to ensure that plant materials used for revegetation match the local environment, and are neither too broad nor unnecessarily local. Ongoing work with native grasses and forbs for conservation and seeds zone development has shown 1) extensive genetic variation across the landscape for plant traits associated with growth and development, 2) growth and development traits are linked to climate variables at seed source locations, suggesting adaptive variation, 3) genetic variation in plant traits can be used with climate data to develop manageable seed zones to guide restoration.
R.C. Johnson is the Research Agronomist at the USDA-ARS Plant Germplasm Testing and Research Unit, in Pullman,Washington. He specializes in management, evaluation, and utilization of plant genetic resources within the National Plant Germplasm System (NPGS). Through partnerships with the BLM, Forest Service, and University scientists, Johnson is working to collect, conserve, and develop seeds zones for key native species in the interior West.
3:00 p.m.
Sierra Nevada Seed Zones for California Native Grasses
Jay H. Kitzmiller
(Presented by: Tom Blush, Regional Geneticist, US Forest Service, Pacific Southwest Region)
Presentation (PDF)
A comprehensive common-garden study was conducted (2005-2007) on 15 test-sites to delineate provisional seed zones for three California native grasses in the 20 million-acre Sierra Nevada Bio-region. This area covers about 3.5 deg latitude or 230 miles, includes both west- and east-slopes, and extends from 2800 to 10,900 ft in altitude. Seed lots of Elymus glaucus (ElGl), Elymus elymoides (ElEl), and Bromus carinatus (BrCa) were collected in 2003 from six national forests and the Lake Tahoe Basin. These are wide-ranging, self-pollinating, prolific seeding, and rapid colonizing perennials that are valued in forest and range ecosystems. Two species and 20-35 seed lots each were generally tested at each site. Mixed models were used to estimate and contrast seed collection zone means, and to determine genotype x environment interactions. Canonical Correlation Analysis (CCA) and trend surface analysis were used to determine the geographic model and the delineation of provisional seed zones. Greatest differences between seed sources were west- vs east-slope. Survival was an important trait for BrCa high elevation tests and for ElEl in Inyo tests, especially at the desert site: Wells. Number of culms (stems) also expressed local and near local source patterns at some “harsh” sites. Leaf width and culm height (length) traits apparently expressed adaptive variation for some species, seedlot, and test site combinations. Seed zones were constructed by merging analysis information from overlapping testable seed source x site groups for the species. Results indicated: 8 seed zones for ElGl on the west-slope, 9 seed zones for BrCa on the west-slope and 3 on the east-slope, and 7 seed zones for ElEl on the east-slope. Many of the proposed zones extend across two or three national forests and across 1000 ft at high elevations and 1500 to 2000 ft at the lowest elevations. A few were unique to a single forest.
Jay Kitzmiller is currently a Consulting Forest Geneticist, living in Paradise, California. Previously, Jay served as Regional Geneticist in the United States Forest Service, Pacific Southwest (PSW) Region for 30 years (1974-2004). Jay developed forest conservation and genetic improvement programs for major conifers, including rust resistant sugar pine. Beginning in the early 1990s he worked with some minor species, such as Port-Orford-cedar, pacific yew, quaking aspen, and with California native grasses. Jay also was employed (1972-1974) by the University of California, Berkeley conducting research on regeneration problems with True Firs (Abies). Jay holds B.S (1966) and M.S. (1968) degrees in Forest Management at West Virginia University, and earned a Ph.D. (1972) in Forest Genetics at North Carolina State University.
4:00 p.m.
Generalized Provisional Seed Zones for Native Plants
Andrew D. Bower, Brad St. Clair, Vicky Erickson
Presentation (PDF)
Deploying vigorous, well adapted, and ecologically appropriate plant materials is a core component of a successful restoration project. The key to identifying appropriate plant materials lies in understanding the genetics of adaptation through common garden studies. However, restoration practitioners often deploy plant species on the landscape for which no seed transfer guidelines have been established through genetic research. What are practitioners to do when no seed transfer guidelines have been established for a species of interest? We have developed generalized provisional seed zones that can be applied to any plant to help guide seed movement. These seed zones area based on the intersection of high resolution (800m x 800m cell size) observed climatic data. The intersection of winter minimum temperature and annual precipitation delineates zones for trees, shrubs, and woody plants, while the intersection of average maximum termperature and precipitation is used for zones for grasses and herbaceous plants. The resulting seed zones represent areas of relative climatic similarity, and movement of seed within these zones should help to minimize maladaptation. Superimposing Omernik’s level III ecoregions over these seed zones helps to distinguish areas that are similar climatically yet different ecologically. These provisional seed zones should be considered a starting point as guidelines for seed transfer, and should be utilized in conjunction with appropriate species-specific information as well as local knowledge of microsite differences.
Andrew has a bachelor’s degree in forestry from UC Berkeley, M.S. in forest science from Oregon State University, and a Ph.D. in forest sciences from University of British Columbia. His doctoral research was on the genetics of whitebark pine and included describing seed transfer guidelines for this species based on a common garden experiment. His professional interests include population and conservation genetics and as a geneticist with the US Forest Service in Corvallis, Oregon he works managing genetic resources for both trees and native plants.
4:30 p.m.
Discussion: Common Garden Studies & Seed Transfer Guidelines
Randy Johnson
