Restoration
The global push to achieve ecosystem restoration targets has resulted in an increased demand for native seeds that current production systems are not able to fulfill. In many countries, seeds used in ecological restoration are often sourced from natural populations. Though providing seed that is reflective of the genetic diversity of a species, wild harvesting often cannot meet the demands for large‐scale restoration and may also result in depletion of native seed resources through over harvesting. To improve seed production and decrease seed costs, seed production systems have been established in several countries to generate native seeds based on agricultural or horticultural production methods or by managing natural populations. However, there is a need to expand these production systems which have a primary focus on herbaceous species to also include slower maturing shrub and tree seed. Here we propose that to reduce the threat of overharvest on the viability of natural populations, seed collection from natural populations should be replaced or supplemented by seed production systems. This overview of seed production systems demonstrates how to maximize production and minimize unintended selection bias so that native seed batches maintain genetic diversity and adaptability to underpin the success of ecological restoration programs.
Ensuring the availability of adequate seed supplies of species and sources appropriate for restoration projects and programs necessitates extensive science‐based planning. The selection of target species requires a review of disturbance conditions and reference areas, development of a reference model, and consideration of specific objectives, timeframes, available resources, and budgets as well as the performance of prospective species in past restoration efforts. Identification of seed sources adapted to site conditions is critical to provide for short‐term establishment and long‐term sustainability. Seed zones and plant movement guidelines provide tools for sourcing plant materials with reduced risk of maladaptation. A seed zone framework also facilitates seed use planning and contributes to stability and predictability of the commercial market, thereby reducing costs and improving the availability of adapted seed supplies. Calculating the amount of seed required for each species is based on seed quality (viability, purity), seed weight, expected seedling establishment, and desired composition of the seeding. If adequate collections from wildland stands are not feasible, then seed increase in seed fields or use of nursery stock may be warranted. Adherence to seed collection and seed production protocols for conserving genetic diversity is critical to protect genetic resources and buffer new seedings and plantings against environmental stressors. Maintenance of genetic diversity becomes even more critical considering current or expected climate change impacts. Collaboration and partnerships can benefit seed selection and procurement programs through sharing of information, coordination in project planning, and increasing the availability of native seed.
Wildfires change plant community structure and impact wildlife habitat and population dynamics. Recent wildfire‐induced losses of big sagebrush (Artemisia tridentata) in North American shrublands are outpacing natural recovery and leading to substantial losses in habitat for sagebrush‐obligate species such as Greater Sage‐grouse. Managers are considering restoration strategies that include planting container‐grown sagebrush to improve establishment within areas using more conventional seeding methods. Although it is thought that planting sagebrush provides initial structural advantages over seeding, empirical comparisons of sagebrush growth are lacking between individuals established post‐fire using both methods. Using a Bayesian hierarchical approach, we evaluated sagebrush height and canopy area growth rates for plants established in 26 seeded and 20 planted locations within the Great Basin. We then related recovery rates to previously published nesting habitat requirements for sage‐grouse. Under average weather conditions, planted or seeded sagebrush will require 3 or 4 years, respectively, and a relatively high density (≥ 2 plants/m2) to achieve the minimum recommended canopy cover for sage‐grouse (15 %). Sagebrush grown in warmer and drier conditions met this cover goal months earlier. Although planted sagebrush reached heights to meet sage‐grouse nesting requirements (30 cm) one year earlier than seeded plants, seeded individuals were ~19 cm taller with 410 cm2 more canopy area than planted sagebrush after 8 years. However, big sagebrush establishment from seed is unreliable. Strategically planting small, high density patches of container‐grown sagebrush in historic sage‐grouse nesting habitat combined with lower density seedings in larger surrounding areas may accelerate sage‐grouse habitat restoration.
Adaptive variation among plant populations must be known for effective conservation and restoration of imperiled species and predicting their responses to a changing climate. Common‐garden experiments, in which plants sourced from geographically distant populations are grown together such that genetic differences may be expressed, have provided much insight on adaptive variation. Common‐garden experiments also form the foundation for climate‐based seed‐transfer guidelines. However, the spatial scale at which population differentiation occurs is rarely addressed, leaving a critical information gap for parameterizing seed‐transfer guidelines and assessing species’ climate vulnerability. We asked whether adaptation was evident among populations of a foundational perennial within a single “empirical” seed‐transfer zone (based on previous common‐garden findings evaluating very distant populations) but different “provisional” seed zones (groupings of areas of similar climate and are not parameterized from common‐garden data). Seedlings from three populations originating from similar conditions within an intermediate elevation were planted into gardens nearby at the same elevation, or 250–450 m higher or lower in elevation and 0.4–25 km away. Substantial variation was observed between gardens in survival (ranging 2%–99%), foliar crown volume (7.8–22.6 dm3), and reproductive effort (0%–65%), but not among the three transplanted populations. The between garden variation was inversely related to climatic differences between the gardens and seed‐source populations, specifically the site differences in maximum–minimum annual temperatures. Results suggest that substantial site‐specificity in adaptation can occur at finer scales than is accounted for in empirical seed‐transfer guidance when the guidance is derived from broadscale common‐garden studies. Being within the same empirical seed zone, geographic unit, and even within 10 km distance may not qualify as “local” in the context of seed transfer. Moving forward, designing common‐garden experiments so that they allow for testing the scale of adaptation will help in translating the resulting seed‐transfer guidance to restoration projects.
Western US sagebrush ecosystems are threatened due to multiple interacting factors: encroachment by conifer woodlands, exotic annual grass invasion, severe wildfire, climate change, and anthropogenic development. Restoration of these communities is primarily focused on reducing conifer species such as western juniper, with the goal of increasing native herbaceous perennials and sagebrush and decreasing exotic annual grass invasion. Assessing the long-term success of restoration treatments is critical for informing future management and treatment strategies since short-term patterns do not generally predict long-term trends. Using a designed experiment from a Wyoming big sagebrush community that was established in 2008, we examined the long-term vegetation response to juniper removal and seeding (cultivar and local) in disturbed and undisturbed areas (slash pile, skid trails, no disturbance). We also examined the landscape scale plant response to juniper removal using repeatedly measured randomly located transects across two restoration units. We found that seeded species persisted in the long term and also mitigated exotic grass increases.
Woodland encroachment is a global issue linked to diminished ecosystem services, prompting the need for restoration efforts. However, restoration outcomes can be highly variable, making it difficult to interpret the ecological benefits and risks associated with woodland-reduction treatments within semiarid ecosystems. We addressed this uncertainty by assessing the magnitude and direction of vegetation change over a 15-year period at 129 sagebrush (Artemisia spp.) sites following pinyon (Pinus spp.) and juniper (Juniperus spp.) (P–J) reduction. Pretreatment vegetation indicated strong negative relationships between P–J cover and the abundance of understory plants (i.e., perennial grass and sagebrush cover) in most situations and all three components differed significantly among planned treatment types. Thus, to avoid confounding pretreatment vegetation and treatment type, we quantified overall treatment effects and tested whether distinct response patterns would be present among three dominant plant community types that vary in edaphic properties and occur within distinct temperature/precipitation regimes using meta-analysis (effect size = lnRR = ln[posttreatment cover/pretreatment cover]). We also quantified how restoration seedings contributed to overall changes in key understory vegetation components. Meta-analyses indicated that while P–J reduction caused significant positive overall effects on all shrub and herbaceous components (including invasive cheatgrass [Bromus tectorum] and exotic annual forbs), responses were contingent on treatment- and plant community-type combinations. Restoration seedings also had strong positive effects on understory vegetation by augmenting changes in perennial grass and perennial forb components, which similarly varied by plant community type. Collectively, our results identified specific situations where broad-scale efforts to reverse woodland encroachment substantially met short-term management goals of restoring valuable ecosystem services and where P–J reduction disposed certain plant community types to ecological risks, such as increasing the probability of native species displacement and stimulating an annual grass-fire cycle. Resource managers should carefully weigh these benefits and risks and incorporate additional, appropriate treatments and/or conservation measures for the unique preconditions of a given plant community in order to minimize exotic species responses and/or enhance desirable outcomes.
This study evaluated the long-term (13 years post-treatment) effectiveness of prescribed fire and mechanical tree removal to re-establish sagebrush steppe vegetation and associated spatial patterns in ground surface conditions and soil hydrologic properties of two woodland-encroached sites. Specifically, we assessed the effects of tree removal on: (1) vegetation and ground cover at the hillslope scale (990 m2 plots) and (2) associated spatial patterns in point-scale ground surface conditions and soil hydrologic properties along transects extending from tree bases and into the intercanopy areas between trees. Both sites were in mid to late stages of woodland encroachment with extensive bare conditions (~60–80% bare ground) throughout a degraded intercanopy area (~75% of the domain) surrounding tree islands (~25% of domain, subcanopy areas). All treatments effectively removed mature tree cover and increased hillslope vegetation. Enhanced herbaceous cover (4–15-fold increases) in burned areas reduced bare interspace (bare area between plants) by at least 4-fold and improved intercanopy hydraulic conductivity (> than 2-fold) and overall ecohydrologic function. Mechanical treatments retained or increased sagebrush and generally increased the intercanopy herbaceous vegetation. Intercanopy ground surface conditions and soil hydrologic properties in mechanical treatments were generally similar to those in burned areas but were also statistically similar to the same measures in untreated areas in most cases. This suggests that vegetation and ground surface conditions in mechanical treatments are trending toward a significantly improved hydrologic function over time. Treatments had limited impact on soil hydrologic properties within subcanopy areas; however, burning did reduce the soil water repellency strength and the occurrence of strong soil water repellency underneath trees by three- to four-fold. Overall, the treatments over a 13-year period enhanced the vegetation, ground surface conditions, and soil hydrologic properties that promote infiltration and limit runoff generation for intercanopy areas representing ~75% of the area at the sites. However, ecological tradeoffs in treatment alternatives were evident. The variations in woodland responses across sites, treatments, and measurement scales in this long-term study illustrate the complexity in predicting vegetation and hydrologic responses to tree removal on woodland-encroached sagebrush sites and underpin the need and value of multi-scale long-term studies.
Over the past decade, Mark Briggs and co-editor, W.R. Osterkamp (retired, USGS), along with 55 stream restoration experts have collaborated on a stream restoration guidebook entitled Renewing Our Rivers: Stream Corridor Restoration in Dryland Regions. The guidebook highlights the main steps in developing a restoration response for damaged stream ecosystems that will have the most likelihood to be successful and viable in the long-term. As part of this webinar, Mark will introduce us to the guidebook, authors, case studies and lessons gained from stream restoration experiences in Australia, Mexico, and U.S. The flow of the presentation will follow the guidebook’s chapters, which reflect the arc of developing a thoughtful and long-term viable stream restoration response and include such themes as:
- Developing realistic and thoughtful restoration goals and objectives
- Assessing the hydrologic and physical conditions of a drainage basin
- Adapting your stream restoration project to climate change
- Quantifying and securing environmental flow
- Implementing your restoration project
- Monitoring and evaluation
- Going long: considerations to ensure your stream corridor restoration effort continues to grow
The Great Basin Native Plant Project, Great Basin Fire Science Exchange, BLM Plant Conservation Program, the US Forest Service Rocky Mountain Research Station, and the Society for Ecological Restoration Great Basin Chapter co-hosted this webinar series on seeding and restoration in 2015 and 2016. The series provides an opportunity to highlight and discuss current research, case-studies, and tools that help inform applied restoration opportunities throughout the Great Basin.
Seed Zones –
Seed zones: Development and use, procurement and deployment, and provisional zones for native plants, presented by Brad St. Clair, Research Geneticist, USFS Pacific Northwest Research Station, Vicky Erikson, Geneticist, USFS Pacific Northwest Region, and Andy Bower, Geneticist, USFS Olympic National Forest
Seed Collection, Seed Increase, and Purchasing Tools –
Wildland seed collection and extraction, presented by Kayla Herriman and Sarah Garvin, USFS Region 6 Bend Seed Extractory, OR
Procurement and application of native plant material in the BLM, presented by Paul Krabacher, BLM
Restoration Equipment and Seeding Strategies –
Post-fire seeding methods for establishing diverse native communities in the Great Basin, presented by Jeff Ott, Research Geneticist and Steve Monsen, Botanist with the USFS- RMRS
Vegetation restoration in response to pinyon and juniper control treatments, presented by Bruce Roundy, Plant Ecologist at Brigham Young University
Assisted succession – Context and tools, presented by Jerry Benson, President, BFI Native Seeds
Restoration of biological soil crusts in the Great Basin, presented by Jayne Belnap, Research Ecologist, USGS
Evaluating strategies for increasing native plant diversity in crested wheatgrass seedings, presented by Kent McAdoo, Rangeland Resources Specialist, University of Nevada Cooperative Extension
Increasing Diversity in Seed Mixes –
Increasing integration of pollinator-friendly forbs in wildland restoration, presented by Byron Love, Ph.D. candidate at Utah State University and technician with the USDA ARS Pollinating Insects Research Unit
The NRCS’s role in developing native plant material for federal land, presented by Derek Tilley, Agronomist and Manager, USDA NRCS Aberdeen Plant Materials Center, ID
Using field studies to find the most promising seed sources for restoration, presented by Beth Leger, Associate Professor of Plant Ecology, University of Nevada, Reno
Weather Variability and Proactive Planning for Restoration –
Weather variability and forecasting tools for short and long term restoration planning, presented by Stuart Hardegree, Plant Physiologist, USDA ARS Northwest Watershed Research Center, Boise, ID
Climate, weather, and sagebrush seed sources: Experimental insights on challenges and opportunities, presented by Matt Germino, Research Ecologist, USGS Snake River Field Station
Seed zones and climate change, presented by Francis Kilkenny, Research Biologist, USFS-RMRS
Sagebrush Seedlings and Plantings –
Sagebrush seed processing and production for restoration in the Great Basin, presented by Clark Fleege, Nursery Manager, USFS Lucky Peak Nursery
An introduction to the Target Plant Concept, presented by Anthony Davis, Director, Center for Forest Nursery and Seedling Research, University of Idaho and Jeremy Pinto, Research Plant Physiologist, USFS RMRS
Southwest Idaho native seed collection, use, and plant material development, presented by Ben Dyer, Fire Ecologist, Upper Snake Field Office BLM, and Danelle Nance, Natural Resource Specialist, Shoshone Field Office BLM
Selecting and Maintaining Genetic Diversity –
Selection of genetically appropriate plant materials for increase, presented by Holly Prendeville, Research Geneticist, USFS PNW
Producing native plant materials for restoration: 10 rules to collect and maintain genetic diversity, presented by Andrea Kramer, Conservation Scientist, Chicago Botanic Garden
Verification of sagebrush subspecies from seed samples and finding the right place for successful restoration, presented by Bryce Richardson, Research Geneticist, USFS RMRS
The incredible diversity of sagebrush chemistry and its potential value in restoration, presented by Justin Runyon, Research Entomologist, USFS RMRS
Pollinators and Insect Predators –
Pollinator-friendly forbs to seed for the sagebrush-steppe, presented by Jim Cane, USDA-ARS Pollinating Insect Research Unit, Utah State University
Restoring shrub-steppe after wildfire: Shrub planting as a viable tool in rehabilitation, presented by Heidi Newsome, Wildlife Biologist, USFWS, Hanford Reach National Monument
Seed Production, Purchase, and Contracting –
Insects affecting native seed production, presented by Bob Hammon, Entomology/Agronomy Extension Agent, Tri River Extension Area
Wildland seed collection: Responding to a changing market, presented by Ed Kleiner, Comstock Seed, Gardnerville, NV
Using native plants in fuel breaks, presented by Mark Williams, BLM, Salt Lake City, UT
Sagebrush Habitat Types and Restoration/Resistance & Resilience –
Sage-grouse forb preference by 12 plant categories, presented by Roger Rosentreter, BLM Idaho Retired State Botanist
Engaging communities in sagebrush restoration: Idaho Fish and Game Southwest Region Volunteer Program, presented by Michael Young, Idaho Fish and Game’s Southwest Region Volunteer Program
Sage-grouse habitat conservation through prisons, presented by Stacy Moore, Ecological Education Program, Institute for Applied Ecology
Description: During this session, USDA Forest Service and collaborative members will explore lessons learned in the first 10 years of CFLRP monitoring – what worked well and what challenges we continue to encounter in the multi-party monitoring of ecological, social, and economic effects. Given those lessons, we will then discuss where we go from here.
Presenters: Tom DeMeo, Regional Ecologist, Pacific Northwest Region, USDA Forest Service; Jessica Robertson, Integrated Restoration Coordinator, USDA Forest Service; CFLRP project practitioners