Informing seed transfer guidelines and native plant materials development: Research supporting restoration across the Colorado Plateau and beyond
As restoration needs for natural landscapes grow due to higher frequency and/or intensity disturbances, pressure from invasive species, and impacts resulting from changing climates, considerable time and resources are being invested to guide the development and deployment of native plant materials (NPMs). Across lower elevations of the Colorado Plateau, a region composed primarily of public land where arid conditions make restoration especially challenging, NPM coordination has been spearheaded by the Bureau of Land Management’s Colorado Plateau Native Plant Program (CPNPP) since 2009.
To help CPNPP achieve its vision of healthy and resilient native plant communities, the Southwest Biological Science Center (SBSC) has provided scientific support and leadership since 2010. SBSC’s research includes field, lab, and greenhouse activities, many of which currently culminate in the development of species-specific seed transfer zones. These zones are developed to protect species’ natural patterns of genetic variation and depict species’ adaptations to regional climatic gradients so that managers and practitioners can make informed seed transfer and plant material decisions.
Background & Importance
The majority of native plant materials (NPMs) used for restoration represent wide-ranging species that provide important ecosystem services like stabilizing soils and filtering water.
Disturbed ecosystems benefit from the use of genetically appropriate NPMs or those that display ecological fitness, are compatible with other species in the plant community, and will not become invasive, because they can rejuvenate ecosystem function.
While many NPMs have been developed, a broader diversity of species and geographic sources is needed to provide the right choices in relation to a restoration site. Determining the right NPM for a restoration site can be tricky, which is why researchers develop tools like seed transfer zones.
Seed transfer zones are maps that allow managers and practitioners to easily match an NPM to areas where it may best be used in a restoration treatment. Guidance on seed transfer has been developed from common garden studies, molecular research, and climate modeling investigations.
All these approaches intend to improve the germination and establishment of NPMs at restoration sites, thereby supporting successful outcomes and stretching limited resources (e.g., time and money).
Genetic data (which hereafter refers to molecular/sequencing data) have broad utility when considering how to use existing NPMs or develop new NPMs. For example, landscape genetic analyses can illuminate patterns of genetic diversity across a species’ distribution and delineate the geographic distribution of evolutionary lineages.
Determining how long evolutionary lineages have been separated from one another and their rates of gene flow (e.g., cross-pollination) can help practitioners identify regions of a species’ range where individuals should not be mixed, even if those individuals occupy similar environments.
In addition, genetic diversity is well suited to determine taxonomic relationships when morphological variation is questionable. Landscape genetics can also identify adaptive genetic variation, or variation that may provide a benefit to the survival (and therefore reproductive capacity) of a species.
For most of the important Colorado Plateau restoration species, knowledge on adaptive differentiation, genetic diversity, and spatial variation in standing genetic diversity is unavailable.
General Methods
Leaf tissue samples for priority restoration species are field collected from sites located across the Colorado Plateau – sampling sites are stratified to represent the dominant, regional climatic gradients.
Colorado Plateau collections are often supplemented with leaf tissues from herbarium vouchers or collected by collaborators so as to incorporate/identify genetic patterns across species’ western distributions.
DNA is extracted and used to develop next-generation sequencing libraries at a laboratory at Northern Arizona University. Libraries are sequenced at the University of Oregon’s Genomics and Cell Characterization Core Facility on an Illumina HiSeq 6000. Data processing and analyses are completed at SBSC and take advantage of the USGS Yeti supercomputer.
Important Results
Genetically informed seed transfer zones for the Colorado Plateau and adjacent regions are available for eight species:
James’ galleta grass (Pleuraphis jamesii; syn. Hilaria jamesii); small-leaf globemallow (Sphaeralcea parvifolia); sand dropseed (Sporobolus cryptandrus); Rocky Mountain beeplant (Cleome serrulata); showy goldeneye (Heliomeris multiflora), rushy milkvetch (Astragalus lonchocarpus); yellow beeplant (Cleome lutea); and hoary tansyaster (Machaeranthera canescens).
Seed transfer zones reflect both genetic differentiation and putative adaptation and are available, along with the zones for other western species, from the Western Wildland Environmental Threat Assessment Center.
Future Directions
The Genetics for Western Restoration and Conservation (GWRC) research group has a variety of ongoing molecular and field-based projects.
For example, we are researching how the agricultural increase of seeds (i.e., the production of native plant materials) affects patterns of genetic diversity, as well as the long-term impacts of native plant materials on their conspecifics at restoration sites.
Please reach out to Rob Massatti (rmassatti@usgs.gov) for more information!
Below are other science projects associated with this project.
Plant responses to drought and climate change in the southwestern United States
Colorado Plateau Extreme Drought in Grassland Experiment (EDGE)
Chronic Drought Impacts on Colorado Plateau Ecosystems (Rain-Out Experiment)
Southwest Energy Exploration, Development, and Reclamation (SWEDR)
Genomic Research Supporting Western Conservation
Wind Erosion and Dust Emissions on the Colorado Plateau
RestoreNet: Distributed Field Trial Network for Dryland Restoration
Colorado Plateau Futures: Understanding Agents of Change on the Colorado Plateau to Facilitate Collaborative Adaptation
Restoration and Ecosystem Recovery Dynamics in Arid and Semiarid Landscapes
Colorado Plateau Native Plant Program Field Trial Study
Dryland Forest Sustainability
Ecohydrology and Climate Change in Drylands
As restoration needs for natural landscapes grow due to higher frequency and/or intensity disturbances, pressure from invasive species, and impacts resulting from changing climates, considerable time and resources are being invested to guide the development and deployment of native plant materials (NPMs). Across lower elevations of the Colorado Plateau, a region composed primarily of public land where arid conditions make restoration especially challenging, NPM coordination has been spearheaded by the Bureau of Land Management’s Colorado Plateau Native Plant Program (CPNPP) since 2009.
To help CPNPP achieve its vision of healthy and resilient native plant communities, the Southwest Biological Science Center (SBSC) has provided scientific support and leadership since 2010. SBSC’s research includes field, lab, and greenhouse activities, many of which currently culminate in the development of species-specific seed transfer zones. These zones are developed to protect species’ natural patterns of genetic variation and depict species’ adaptations to regional climatic gradients so that managers and practitioners can make informed seed transfer and plant material decisions.
Background & Importance
The majority of native plant materials (NPMs) used for restoration represent wide-ranging species that provide important ecosystem services like stabilizing soils and filtering water.
Disturbed ecosystems benefit from the use of genetically appropriate NPMs or those that display ecological fitness, are compatible with other species in the plant community, and will not become invasive, because they can rejuvenate ecosystem function.
While many NPMs have been developed, a broader diversity of species and geographic sources is needed to provide the right choices in relation to a restoration site. Determining the right NPM for a restoration site can be tricky, which is why researchers develop tools like seed transfer zones.
Seed transfer zones are maps that allow managers and practitioners to easily match an NPM to areas where it may best be used in a restoration treatment. Guidance on seed transfer has been developed from common garden studies, molecular research, and climate modeling investigations.
All these approaches intend to improve the germination and establishment of NPMs at restoration sites, thereby supporting successful outcomes and stretching limited resources (e.g., time and money).
Genetic data (which hereafter refers to molecular/sequencing data) have broad utility when considering how to use existing NPMs or develop new NPMs. For example, landscape genetic analyses can illuminate patterns of genetic diversity across a species’ distribution and delineate the geographic distribution of evolutionary lineages.
Determining how long evolutionary lineages have been separated from one another and their rates of gene flow (e.g., cross-pollination) can help practitioners identify regions of a species’ range where individuals should not be mixed, even if those individuals occupy similar environments.
In addition, genetic diversity is well suited to determine taxonomic relationships when morphological variation is questionable. Landscape genetics can also identify adaptive genetic variation, or variation that may provide a benefit to the survival (and therefore reproductive capacity) of a species.
For most of the important Colorado Plateau restoration species, knowledge on adaptive differentiation, genetic diversity, and spatial variation in standing genetic diversity is unavailable.
General Methods
Leaf tissue samples for priority restoration species are field collected from sites located across the Colorado Plateau – sampling sites are stratified to represent the dominant, regional climatic gradients.
Colorado Plateau collections are often supplemented with leaf tissues from herbarium vouchers or collected by collaborators so as to incorporate/identify genetic patterns across species’ western distributions.
DNA is extracted and used to develop next-generation sequencing libraries at a laboratory at Northern Arizona University. Libraries are sequenced at the University of Oregon’s Genomics and Cell Characterization Core Facility on an Illumina HiSeq 6000. Data processing and analyses are completed at SBSC and take advantage of the USGS Yeti supercomputer.
Important Results
Genetically informed seed transfer zones for the Colorado Plateau and adjacent regions are available for eight species:
James’ galleta grass (Pleuraphis jamesii; syn. Hilaria jamesii); small-leaf globemallow (Sphaeralcea parvifolia); sand dropseed (Sporobolus cryptandrus); Rocky Mountain beeplant (Cleome serrulata); showy goldeneye (Heliomeris multiflora), rushy milkvetch (Astragalus lonchocarpus); yellow beeplant (Cleome lutea); and hoary tansyaster (Machaeranthera canescens).
Seed transfer zones reflect both genetic differentiation and putative adaptation and are available, along with the zones for other western species, from the Western Wildland Environmental Threat Assessment Center.
Future Directions
The Genetics for Western Restoration and Conservation (GWRC) research group has a variety of ongoing molecular and field-based projects.
For example, we are researching how the agricultural increase of seeds (i.e., the production of native plant materials) affects patterns of genetic diversity, as well as the long-term impacts of native plant materials on their conspecifics at restoration sites.
Please reach out to Rob Massatti (rmassatti@usgs.gov) for more information!
Below are other science projects associated with this project.