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The Right Seed in the Right Place at the Right Time

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Sara F Oldfield
Sara F Oldfield
Peggy Olwell
Peggy Olwell
Peggy Olwell
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http://bioscience.oxfordjournals.org XXXX XXXX / Vol. XX No. X •BioScience 1
The Right Seed in the Right Place at the
Right Time
SARA OLDFIELD AND PEGGY OLWELL
North American native plant
seed is a valuable commodity and
one that is in short supply. Current
production may not always meet the
growing demand, which is primarily
for restoration of degraded landscapes.
In response to this shortage, a strong
and diverse coalition of federal and
other agencies, as well as nonprofit
organizations and private sector busi-
nesses, has developed the ambitious
National Seed Strategy. The mission
of the strategy is to ensure the avail-
ability of genetically appropriate seed
reserves to restore viable, productive
plant communities and sustainable
ecosystems.
Seed production in natural ecosys-
tems ensures the regeneration of locally
adapted plant species, which provide
habitat for wildlife, stabilize soils, con-
trol surface-water flow, and contribute
to ecological integrity and resilience.
The United States has a native flora
of over 18,000 species. In the west-
ern states, which have more diverse
ecosystems and higher levels of plant
endemism, there are around 14,600
native plant taxa. A recent assessment
identified only 1949 of these as com-
mercially available for use in restora-
tion, the majority of species being
sold by only one producer (White et
al. 2015). This affects the restoration
potential for degraded natural areas
affected by human or natural events.
Efforts to diversify and scale up native
seed production depend to a large
extent on adequate and reliable fund-
ing for development and ultimately on
the market. Federal agencies are major
buyers of native seed for land rehabili-
tation and restoration. The Bureau of
Land Management (BLM), the largest
federal land manager, alone purchases
an average of 1.4 million kilograms of
seed per year and often needs much
more.
The US government has been aware
of the critical shortage of native plant
materials for over a decade. The exten-
sive wildfires of 1999 and 2000 led
Congress to direct the BLM and the
United States Forest Service (USFS)
to develop a stable and economi-
cal supply of native plant materials
for restoration and rehabilitation
efforts on public lands (http://io.aibs.
org/106914). The BLM and USFS
responded by establishing the Native
Plant Materials Development Program
and the Native Plant Restoration
Program, respectively. The immediate
focus was to increase the availability of
diverse native plant materials and to
foster more efficient management of
that supply.
The two programs, mandated at the
turn of the century, have achieved con-
siderable success, but action needs to
be scaled up to address growing eco-
logical challenges. The causes of land
degradation in the western states are
now exacerbated by climate change.
The resulting impacts on native plant
populations and communities present
urgent land-management challenges.
The National Fish, Wildlife, and Plants
Climate Adaptation Strategy, man-
dated by Congress in 2009, recog-
nizes that “management plans in this
new era of climate change must take
into account the differing capacities of
individual species and ecosystems to
adapt to changing conditions and sus-
tain cultural, recreational, and com-
mercial uses.”
Old and new threats
Prolonged drought is a significant
threat throughout the Southwest, with
wildfires increasing in regularity and
intensity. A related threat is the spread
of invasive and noxious weeds. The
natural resilience of heavily grazed
native grassland ecosystems has been
weakened by the use of introduced
grass species initially intended to sta-
bilize soils and improve productivity.
Modified grasslands can be rapidly
colonized by pernicious introduced
species brought in by the movement of
people, their crops, garden plants, and
livestock.
Efforts to restore the land involve
both tackling invasive species and
restoring native plants. In the range-
lands and steppes of the Great Basin
and inland Pacific Northwest, cheat-
grass (Bromus tectorum), an invasive
species introduced from Europe in the
1880s, is spreading fast. Cheatgrass-
dominated land burns every 2–5 years.
Land rich in sagebrush and other
native species, in contrast, is more
ecologically resilient, burning every
11–200 years (Koch et al. 2015).
In January 2015, an order by the
secretary of the Department of the
Interior called for enhanced action to
prevent and suppress rangeland fire
and to restore extensive fire-damaged
sagebrush communities. The order
specifically calls for the utilization of
locally adapted seeds and native plant
materials for vegetation management
and restoration. It therefore provides
a powerful supporting motivation for
the National Seed Strategy.
Generally, the plant species used
in a restoration project vary accord-
ing to the vegetation type, land use,
extent of degradation, availability of
material, and established practices.
Restoration projects often focus on
the use of dominant plant species
because these are more widely avail-
able and are considered to be more
BioScience Advance Access published September 16, 2015
by guest on September 24, 2015http://bioscience.oxfordjournals.org/Downloaded from
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2 BioScience •XXXX XXXX / Vol. XX No. X http://bioscience.oxfordjournals.org
make timely, informed seeding deci-
sions for ecological restoration; and
to develop strategies for internal and
external communication.
With the launch of the National
Seed Strategy, federal agencies with
responsibility for managing nearly 30
percent of the US landmass will work
together to facilitate native seed pro-
duction from diverse native plants. A
business plan is currently being devel-
oped that will highlight opportunities
for the private sector to become more
involved in supporting the strategy.
Nongovernmental organizations are
on board. Scientific, technical, and
cultural challenges remain, but the
National Seed Strategy will represent a
quiet but profound revolution in land
management.
References cited
Haidet M, Olwell P. 2015. Seeds of success: A
national seed banking program working
to achieve long-term conservation goals.
Natural Areas Journal 35: 165–173.
Havens K, Vitt P, Still S, Kramer AT, Fant JB,
Schatz K. 2015. Seed sourcing for restoration
in an era of climate change. Natural Areas
Journal 35: 122–133.
Koch G, St. Clair B, Erickson V. 2015. No Place
Like Home: Using Seed Zones to Improve
Restoration of Native Grasses in the West.
Science Findings no. 171. US Department
of Agriculture, US Forest Service, Pacific
Northwest Research Station.
White A, Fant J, Kramer A. 2015. Restoring spe-
cies diversity: Are vulnerable plant species
falling through the cracks? Paper presented
at the National Native Seed Conference;
13–16 April 2015, Santa Fe, New Mexico.
Wood TE, Doherty K, Padgett W. 2015.
Development of native plant materials for
restoration and rehabilitation of Colorado
Plateau Ecosystems. Natural Areas Journal
35: 134–150.
Sara Oldfield (sara@saraoldfield.net) is an
independent botanical consultant working with
the Chicago Botanic Garden. Peggy Olwell is the
Plant Conservation Program lead for the Bureau
of Land Management and chair of the Plant
Conservation Alliance Federal Committee.
doi:10.1093/biosci/biv127
Endangered Species Act, the bird has
declined dramatically over the past
100 years because of habitat loss. The
BLM is making major efforts to restore
sagebrush habitats on its land. In the
East, the bobwhite quail (Colinus vir-
ginianus) is another game bird that is
attracting widespread concern. The
National Bobwhite Conservation
Initiative, developed by 25 state wild-
life agencies, with many conservation
and research partners, is restoring
native grassland habitats and healthy
populations of wild quail.
So what are the National Seed
Strategy’s chances of success? The ini-
tial signs are promising: a high-level
policy framework, background initia-
tives that the strategy will build upon,
and a strong coalition of support.
The National Seed Strategy will, for
example, build on the work of Seeds
of Success, a national native seed–
collection program led by the BLM.
In the past 15 years, Seeds of Success
has made more than 16,500 seed
collections representing over 5000 taxa
(Haidet and Olwell 2015). Collecting
seed from native species is the first
stage in developing a reliable com-
mercial source, which takes on average
10–20 years per species. In parallel,
germination and propagation proto-
cols have been developed for over 3000
species. Furthermore, over 120 native
species have been made commercially
available, and foundation seed for over
70 additional species has been pro-
vided to commercial growers. Two US
Department of Agriculture facilities
provide long-term seed storage.
The four interrelated goals of the
National Seed Strategy also bode well:
to identify seed needs and ensure
the reliable availability of genetically
appropriate seed; to identify research
needs and conduct research to pro-
vide genetically appropriate seed and
to improve technology for seed pro-
duction and ecological restoration; to
develop tools that enable managers to
important for ecosystem functioning.
The importance of using native mate-
rial, the importance of genetic prov-
enance, and the use of cultivars are still
widely debated, however. Before 2000,
grasses, predominantly nonnative
ones, have dominated restoration use.
On the Colorado Plateau, for exam-
ple, nonnative crested wheatgrass has
been planted extensively to enhance
livestock grazing after the removal of
pinyon–juniper woodland. Although
it is commonly held that introduced
species perform better than natives,
this view is based more on philosophi-
cal preference than on data (Wood
et al. 2015). Likewise, the notion that
the use of cultivars of native species
selected for vigor, seed production,
disease resistance, and habit is highly
advantageous—not least because culti-
var seeds are widely available and easy
to sow using seed drills—is common.
However, cultivars, with their limited
or altered genetic variation, may have
poor ability to adapt to climate change.
New attitudes needed
National policy directives call for the
use of native plant species in restoration
to the extent practicable. To address
this imperative, a change in cultural
attitudes will be required—specifically,
a shift away from agronomic toward
ecological restoration models. Science
alone may not convince all practi-
tioners, but demonstrating restora-
tion success, adaptive management,
effective communication, and public
support will strengthen the case for
using native, locally adapted seeds.
Unfortunately, native plants do not
have the charisma they deserve, but
flagship animal species can help make
a strong case for restoring biodiverse,
plant-rich ecosystems.
In the West, the greater sage grouse
(Centrocercus urophasianus), a species
heavily dependent on sagebrush land-
scapes, is one such species. Currently
being considered for listing under the
by guest on September 24, 2015http://bioscience.oxfordjournals.org/Downloaded from
... However, the demand for seeds and plant material from the growing number and scale of restorative activities places considerable pressure on remnant ecosystems to provide these resources (Nevill et al. 2018). The urgent need to increase the amounts of viable seeds and nursery-grown plants with known provenance available for restorative activities has led to the development of agricultural production systems for native seeds and nursery stock (Merritt & Dixon 2011;Oldfield & Olwell 2015;Nevill et al. 2016) and brought conceptualization of a "supply chain" for these resources into the international scientific discourse (Broadhurst et al. 2015). ...
... Building supply chain capacity that better synchronizes supply and demand to ensure "the right seed, in the right place, at the right time" (Oldfield & Olwell 2015) requires more than addressing relationship fragmentation among producers and end-users. Numerous "public good" aspects of seed and plant material supply cannot be fully realized or efficiently addressed through market mechanisms alone. ...
Restoration seed and plant material supply chains are complex social networks
Article
Full-text available
  • Sep 2024
Previous studies have advanced the conceptual framing of a “supply chain” to describe and examine key steps, inputs, and flows related to the production and use of seed and plant material in ecological restoration. However, these studies have paid less attention to investigating interrelationships among social actors throughout the “supply chain” stages for ecological restoration and allied activities. We applied social network analysis metrics to evaluate the number, kind, and strength of relationships among 157 social actors in the nine‐state region of the Northeastern United States, where rapid growth in restoration activities is driving a demand surge for native seed and plant materials. Restoration supply chains are more complex than previous conceptualization suggests, and we argue that the term “restoration supply networks” is more illustrative of this complexity. Results highlighted interdependency among different sectors, marked variation in input and output flows across spatial–temporal scales, and interplay among linear and nonlinear supply chain steps. The restoration supply network in the study area had a core–periphery structure, with a core comprising end‐users such as government agencies, design and build contractors, and non‐profit organizations surrounded by a periphery of seed and plant material suppliers. It is important to avoid oversimplifying seed and plant material supply chains as linear systems with strong linkages. Understanding relationship patterns among supply network actors can enhance communication, coordination, and collaboration among actors in all key restoration supply chain steps, a prerequisite to overcoming seed and plant material bottlenecks and meeting global restoration goals in the coming decades.
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... Although the restoration pool has grown substantially in many regions, commercially available species may represent a selective subset of the regional pool. Restoration practitioners often select species with high seed availability and reintroduction success, over species that more closely approximate historical communities or promote life-form diversity (Leger & Baughman 2015;Oldfield & Olwell 2015;Holl et al. 2022). If commercially available species represent a nonrandom subset of the regional pool, this could influence the composition and diversity of seed mixes employed in restoration (Ladwig et al. 2020;Zinnen & Matthews 2022b). ...
... On the other hand, highly conservative species may be difficult to grow for seed production, or have a smaller range, and thus limited restoration demand. Land managers tend to choose more dominant species for purchase (Oldfield & Olwell 2015;Holl et al. 2022), so demand for species of moderate conservatism might precipitate an increase in inventory for these species. The higher availability of common species may be explained by ease of production, where rarer species may be harder to collect from appropriate wild populations, or harder to propagate based on differences in reproduction methods or conditions (Lesage et al. 2018;Holl et al. 2022). ...
Common, showy, and perennial species dominate a restoration species pool
Article
Full-text available
  • Jul 2023
  • RESTOR ECOL
Native seed vendors are a primary source of germplasm for restoration projects; however, most plant species are not commercially available. Preferences in the types of species that vendors grow and sell may limit the similarity between reference communities and reconstructed ones established from seed mixes. We tested whether a restoration species pool shows preference for certain groups of species, focusing on the Ozark Highland Ecoregion (midcontinent United States). We identified the pool of 1,082 candidate herbaceous plant species appropriate for restoration projects on upland habitats in this region, and then surveyed nine regional seed vendors to assess their commercial availability. Commercially available species were more likely to be forbs over graminoids, perennials over annuals, and common species with larger ranges and moderate conservatism scores. Within forbs, taller species and those with longer bloom durations were favored. Species with affinity to open habitats (e.g. grassland) were more likely to be available from multiple vendors than those from woodlands and forests. Encouragingly, 454 (42%) of the species in this regional pool were available. However, this means that most species in the region are not likely to be included in seed mixes, unless they are hand-collected from remnant populations. This restoration pool favors common and showy species, which is consistent with previous studies showing these kinds of species tend to dominate seed mixes and restored plant communities. We identified 39 species that were not available from any of the vendors surveyed, which we recommend as candidates for expansion of the Ozark restoration species pool.
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... To maximize the likelihood that plant material is adapted to the conditions at a restoration site, and minimize the risk of negative genetic consequences, practitioners rely on appropriate seed sourcing (Stritch et al. 2010;Oldfield & Olwell 2015;Balazs et al. 2020). Ideally, plant material is both an ecological and genetic match for a restoration site, allowing for high establishment and survival in the short term, high population and community resilience in the long term, and low risk of harmful genetic outcomes (e.g. ...
... Seed transfer zones outline the geographic regions within which plant material should be moved to maximize restoration success and minimize negative, unintended impacts (Oldfield & Olwell 2015). A basic assumption of STZs is that material sourced from within that zone will exhibit similar traits (Westfall 1992;Joshi et al. 2001;Hereford 2009). ...
Recruitment varies among milkweed seed sources for habitat specialist but not generalist
Article
  • May 2022
If sufficient seedling establishment can be achieved, seed‐based restoration provides an affordable, active restoration approach that can be implemented quickly at scale. However, establishment has served as a major restoration bottleneck, highlighting the need for improved understanding of seed germination niche and interactions with site conditions. Germination niche breadth (NB) is expected to increase with gene flow, resulting in broader environmental tolerance range, reduced sensitivity to site conditions, and less variation among seed sources. To investigate how germination NB relates to inter‐ and intraspecific variation in establishment from seed, we compared field recruitment for two milkweeds (Asclepias), the larval host plant of the monarch butterfly and thus a high priority group for habitat creation. Consistent with species‐level NB derived from lab trials, there was strong evidence that early life stages of the habitat specialist (A. incarnata) varied among seed collection regions (separated by 423‐572 km) but no evidence that the generalist (A. syriaca) varied among seed sources collected across a ~750 km transect. Regeneration trends demonstrate that A. incarnata is significantly more sensitive to seed source and therefore requires more restricted seed zones. However, climate change may necessitate that we separate seed collection zones from seed application zones, upending the traditional framework of seed transfer zones. Until taxon‐specific studies have identified the scale of adaptive, phenotypic variance, restoration practitioners should continue to adjust the scale of seed collection zones for milkweeds and other taxa based on species traits known to influence gene flow, such as abundance and habitat specificity. This article is protected by copyright. All rights reserved.
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... Similar challenges are reported from other countries, where practitioners sometimes cannot apply the technical solutions proposed by the academy and disagree regarding technical problems (Smith et al. 2007). The US National Seed Strategy is an example of an approach based on a coalition of government agencies, nongovernmental organisations, and the scientific academy to improve public policy effectiveness and support for seed and seedling production (Oldfield and Olwell 2015). In 2001, there has been a similar endeavour with national edicts for the organisation of seed networks in Brazil (Piña-Rodrigues et al. 2015). ...
... Demand can only be improved by public policies that enforce restoration. Governmental agencies can be the leading consumers of native seeds and seedlings for habitat restoration, as is the case in the USA (Oldfield and Olwell 2015). Adequate policies can also promote the establishment of a market for restoration . ...
Behind the forest restoration scene: a socio-economic, technical-scientific and political snapshot in Amazonas, Brazil
Article
Full-text available
  • Mar 2022
Conservation of the Amazon rainforest is a global concern and is supported by the Brazilian government’s ratification of the Bonn Challenge and Paris Agreement and the introduction of national regulations on vegetation protection and restoration. Amazonas is the largest and least deforested of the states occupied by the Brazilian Amazon (< 3%). We carried out a survey on the current state and growth potential of seed and seedling production in Amazonas state, pointing out constraints where future investment can promote the achievement of large-scale restoration commitments. We visited the 35 officially registered seed producers or nurseries working with native seeds and interviewed their owners or managers using open and closed questions. Enterprises were mainly privately-owned family businesses with small production (10,001 - 100,000 seedlings per year) and concentrated in the metropolitan area of the state capital Manaus. We uncovered a further 54 non-officially registered nurseries. Annual production (2018) was almost four tons of seeds and nearly ten million seedlings. According to the owners, production could be increased five to seven times with existing infrastructure. Production is focused foremost on species for food production (48% seeds, 74% seedlings), while ecological restoration only makes up 35% of seed and 8% of seedling use. Major bottlenecks cited by the producers were low demand for native tree species, high transportation costs and excessive bureaucracy. To achieve large-scale restoration, we recommend enforcement of national policies for vegetation protection and restoration, and a restructuring of the seed and seedling sector with a bottom-up approach.
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... Demographic, weather, or plantcommunity (invasion) risks can interfere with recovery following initial establishment of restoration species, especially in semiarid landscapes (Shriver et al. 2019, O'Connor et al. 2020, and diminish outcomes of even the best seeding implementation practices (e.g. Oldfield and Olwell 2015). Here, we demonstrate how a suite of early indicators of subsequent restoration success can be identified without use of inferential statistics. ...
View
... Importantly, this type of approach can be achieved while still using biocrust species native to the restoration site to avoid unintended consequences of introducing harmful microorganisms (Bethany et al. 2022). This restoration tactic is similar to the vision outlined by the U.S. National Seed Strategy of providing the "right seed in the right place at the right time" and represents a promising direction for targeted biocrust restoration (Oldfield & Olwell 2015). ...
Inoculated biocrust cover and functions diverged over a gradient of soil textures and water availability
Article
  • Mar 2024
Restoring biological crust (biocrust) in disturbed drylands is challenging due to the difficult environmental conditions, such as limited soil moisture, low soil nutrients, and extreme temperatures, that impede growth. Understanding how the key components of biocrust—mosses, lichens, and cyanobacteria—react to different environmental factors informs the optimal timing, locations, and species composition for biocrust reintroduction, thereby increasing the likelihood of establishment. Here, we inoculated soils with a diverse range of biocrust organisms, analogous to seeding an area with diverse vascular plant seeds, and varied environmental conditions to observe how these changes influenced the development and functions of reintroduced biocrust. We found that by manipulating soil texture and time spent wet, we can change the proportional cover of biocrust within a restoration‐like setting. Specifically, we found that 4 months after inoculation, finer textured soils that received more water become dominated by moss cover, while coarser textured soils with less water remained dominated by cyanobacteria cover, and the interactions between texture and time spent wet strongly influenced cover. We found biocrust morphological group cover had a small, but detectable, effect on ecosystem functions (soil stability and nitrogenase activity, a proxy for nitrogen fixation), but that environmental conditions had a stronger impact on the functions we measured. Manipulative experiments in controlled environments, like this one, can help elucidate the mechanisms underlying the establishment rate and patterns of biocrusts post‐inoculation, and inform implementation of inoculations in the field.
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... The Intermountain West is made up of four major geographic areas-the Great Basin, Colorado Plateau, Middle Rocky Mountains, and Northern Rocky Mountains. Much of the focus of restoration and the development of plant materials in the Intermountain West has been related to post-fire restoration, with extensive involvement of the U.S. Bureau of Land Management (BLM) and the U.S. Forest Service (USFS; National Academies of Sciences, Engineering, and Medicine 2023; Oldfield & Olwell 2015). However, the need for wetland restoration is also great, as aquatic habitats are naturally scarce in the region and dwindling due to human use and climate change (Downard et al. 2014(Downard et al. , 2017Kingsford et al. 2016). ...
Got plants? Availability of and challenges to production of native plants for wetland restoration
Article
  • Mar 2024
As the U.N. Decade on Restoration progresses, the demand for genetically and species‐diverse native plant materials for restoration is expected to increase. However, little is known about the availability of plant materials for restoration, particularly in wetlands, which have lagged behind in restoration research. Given the crucial role wetlands play in providing ecosystem services, particularly in semi‐arid regions worldwide, it is important to understand the availability of wetland plant materials for restoration. We surveyed plant material vendors in the Intermountain West of the United States, a vast region containing hundreds of millions of hectares of private working lands and protected areas. We sought to determine the breadth and diversity of species and materials available for restoration, the practices used by vendors, and the challenges they face. We found far lower availability of aquatic, emergent, and meadow wetland species compared to riparian and terrestrial species. To improve species availability, vendors need financial incentives to produce new or difficult‐to‐propagate species and clearer feedback from customers on what species meet their restoration goals. Market fluctuations are the biggest challenge that vendors face, and creating consistent demand is the most important way to overcome this challenge. Overall, vendors follow best practices for obtaining and maintaining genetic diversity in their seed and plant collections, a critical component to meeting restoration goals. However, there are still some opportunities to improve best practices. The results add to the understanding of the challenges in meeting plant material demand for restoration in wetlands regionally and globally.
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... Alternatively, guidance may dictate that low probability locations are to be avoided when collecting seeds intended for NPM development, as the resulting materials would only be suitable for those same areas, if one goal of management using populations is to protect the genetic integrity and patterns of biodiversity. Given the investment required to develop one NPM(McCormick et al., 2021) and the number of new NPMs needed to support restoration (e.g.Oldfield & Olwell, 2015), managing by species' innate patterns of diversity can decrease the complexity of restoration planning and simultaneously supports successful outcomes, as there are typically fewer genetically defined populations for a species compared to the number of physiographic regions it is distributed across (e.g.Massatti et al., 2018;Massatti & Knowles, 2020). ...
Spatially explicit management of genetic diversity using ancestry probability surfaces
Article
Ecological restoration and conservation efforts are increasing worldwide and the management of intraspecific genetic variation in plants and animals, an important component of biodiversity, is increasingly valued. As a result, tailorable, spatially explicit approaches to map genetic variation are needed to support decision‐making and management frameworks related to the recovery of threatened and endangered species and the maintenance of genetic resources in species utilized by humans, such as for restoration or agricultural purposes. Here, we describe and demonstrate a workflow to spatially interpolate patterns of genetic differentiation using novel functions in the r package popmaps ( Population Management using Ancestry Probability Surfaces). Our approach uses empirical genetic data to estimate ancestry coefficients across a user‐defined landscape correlated with patterns of differentiation in the focal species. The resulting surface, which we term the ancestry probability surface, includes two components: hard population boundaries and estimations of uncertainty that represent confidence in population assignments (i.e. ancestry probabilities). An ancestry probability surface developed for Hilaria jamesii , an important graminoid utilized in restoration across the western United States, demonstrates the functionality of popmaps . Genetic distances among empirical sites correlated better with least‐cost distances across suitable habitat than with geographical distances, informing the surface over which the interpolation was conducted (i.e. a model indicating habitat suitability). A jackknifing procedure identified parameter values resulting in robust population assignments across the species' range, which were utilized in downstream analyses to estimate ancestry coefficients from empirical data. Ancestry coefficients were translated into ancestry probabilities, which tended to be low for cells that were intermediate in distance between empirical sampling locations representing different populations or when influenced by empirical sampling locations with mixed genetic ancestry. popmaps allows users to tailor parameter values and analytical approaches and thereby incorporate species‐specific biological characteristics and desired levels of uncertainty into maps illustrating patterns of genetic differentiation. Ancestry probability surfaces may be used to guide management or investigate further ecological or evolutionary hypotheses. We discuss how maps produced by popmaps can inform multiple management challenges including species recovery planning and the utilization of commonly used species in restoration.
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... This pattern holds at multiple levels of organization from the regional to the plant community and genotypic levels (Oliver et al., 2015). Awareness of the fundamental role of diverse, connected ecosystems has resulted in a paradigm shift in restoration ecology, from previous efforts tailored for rapid soil stability and erosion control (e.g., use of cultivars or soil-stabilizing species from outside regions) to native plant materials development programs aimed at increasing local seed reserves, promoting genetic diversity, and minimizing risk from long-distance seed transfer (Kettenring et al., 2014;Oldfield & Olwell, 2015;Olwell & Riibe, 2016). Substantial challenges remain for restoration practitioners seeking to apply these principles across a variety of disturbed environments. ...
Seed Menus: An integrated decision‐support framework for native plant restoration in the Mojave Desert
Article
Full-text available
  • Apr 2022
The combination of ecosystem stressors, rapid climate change, and increasing landscape-scale development has necessitated active restoration across large tracts of disturbed habitats in the arid southwestern United States. In this context, programmatic directives such as the National Seed Strategy for Rehabilitation and Restoration have increasingly emphasized improved restoration practices that promote resilient, diverse plant communities, and enhance native seed reserves. While decision-support tools have been implemented to support genetic diversity by guiding seed transfer decisions based on patterns in local adaptation, less emphasis has been placed on identifying priority seed mixes composed of native species assemblages. Well-designed seed mixes can provide foundational ecosystem services including resilience to disturbance, resistance to invasive species, plant canopy structure to facilitate natural seedling recruitment, and habitat to support wildlife and pollinator communities. Drawing from a newly developed dataset of species distribution models for priority native plant taxa in the Mojave Desert, we created a novel decision support tool by pairing spatial predictions of species habitat with a database of key species traits including life history, flowering characteristics, pollinator relationships, and propagation methods. This publicly available web application, Mojave Seed Menus, helps restoration practitioners generate customized seed mixes for native plant restoration in the Mojave Desert based on project locations. Our application forms part of an integrated Mojave Desert restoration program designed to help practitioners identify species to include in local seed mixes and nursery stock development while accounting for local adaptation by identifying appropriate seed source locations from key restoration species.
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Concordant Signal of Genetic Variation Across Marker Densities in the Desert Annual Chylismia brevipes Is Linked With Timing of Winter Precipitation
Article
Full-text available
Climate change coupled with large‐scale surface disturbances necessitate active restoration strategies to promote resilient and genetically diverse native plant communities. However, scarcity of native plant materials hinders restoration efforts, leading practitioners to choose from potentially viable but nonlocal seed sources. Genome scans for genetic variation linked with selective environmental gradients have become a useful tool in such efforts, allowing rapid delineation of seed transfer zones along with predictions of genomic vulnerability to climate change. When properly applied, genome scans can reduce the risk of maladaptation due to mismatches between seed source and planting site. However, results are rarely replicated among complimentary data sources. Here, we compared RAD‐seq datasets with 819 and 2699 SNPs (in 625 and 356 individuals, respectively) from the Mojave Desert winter annual Chylismia brevipes. Overall, we found that the datasets consistently characterized both neutral population structure and genetic–environmental associations. Ancestry analyses indicated consistent spatial genetic structuring into four regional populations. We also detected a marked signal of isolation by resistance (IBR), wherein spatial genetic structure was better explained by habitat resistance than by geographic distance. Potentially adaptive loci identified from genome scans were associated with the same environmental gradients—fall precipitation, winter minimum temperature, and precipitation timing—regardless of dataset. Paired with our finding that habitat resistance best explained genetic divergence, our results suggest that isolation of populations within environmentally similar habitats—and subsequent local adaption along gradients parallel to these habitats—drive genome‐wide divergence in this species. Moreover, strong genetic associations with winter precipitation timing, along with forecasted shifts in precipitation regime due to midcentury climate change, could impact future population dynamics, habitat distribution, and genetic connectivity for C. brevipes populations within the Mojave Desert.
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Development of Native Plant Materials for Restoration and Rehabilitation of Colorado Plateau Ecosystems
Article
Full-text available
  • Jan 2015
The native plant communities of the Colorado Plateau have been substantially degraded by human activity, yet in many areas retain a basic natural ecologic integrity. The more heavily impacted regions often require active intervention. Historically, this intervention has been conducted primarily by seeding introduced grasses selected for their forage characteristics. Recent management initiatives that reflect broader goals have highlighted the need to develop native plant materials that can be used to return diverse, resilient communities to degraded areas. The Colorado Plateau Native Plant Program was established to identify the best native plant species, and seed sources within species, that can be used to meet this need. We present an overview of the Program's past and current activities and highlight research and development strategies used to increase the availability of native plant materials adapted to target sites.
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Seed Sourcing for Restoration in an Era of Climate Change
Article
Full-text available
  • Jan 2015
Proper sourcing of seed for ecological restoration has never been straightforward, and it is becoming even more challenging and complex as the climate changes. For decades, restoration practitioners have subscribed to the "local is best" tenet, even if the definition of "local" was often widely divergent between projects. However, given our increasing ability to characterize habitats, and rapid climate change, we can no longer assume that locally sourced seeds are always the best or even an appropriate option. We discuss how plants are responding to changing climates through plasticity. adaptation, and migration, and how this may influence seed sourcing decisions. We recommend focusing on developing adequate supplies of "workhorse" species, undertaking more focused collections in both "bad" years and "bad" sites to maximize the potential to be able to adapt to extreme conditions as well as overall genetic diversity, and increasing seed storage capacity to ensure we have seed available as we continue to conduct research to determine how best to deploy it in a changing climate.
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Seeds of Success: A National Seed Banking Program Working to Achieve Long-Term Conservation Goals
Article
  • Jan 2015
Seeds of Success (SOS) is a national native seed collection program, led by the US Department of Interior Bureau of Land Management in partnership with numerous federal agencies and nonfederal organizations. The mission of the SOS is to collect wildland native seed for long-term germplasm conservation and for use in seed research, development of native plant materials, and ecosystem restoration. Each year about 50 SOS teams are stationed across the United States to make seed collections following a single technical protocol. SOS collections are divided into a long-term conservation storage collection, which is stored at multiple USDA Agricultural Research Service seed storage facilities, and a working collection, which is stored at partner institutions and made available for research. In addition to collecting and banking native species for future uses, SOS provides seed that can be increased to provide genetically appropriate plant materials for ecological restoration of disturbed lands. Seed collection is an efficient and cost-effective method for conserving the diversity of plant species into the future. Partners located throughout the United States are critical to the success of this program.
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Restoring species diversity: Are vulnerable plant species falling through the cracks?
  • A White
  • J Fant
  • A Kramer