Synecology
Annual Newsletter of the Southeastern Center for Conservation ATLANTA BOTANIC AL GARDE N
Magnolia maudiae (Photo: Ethan Guthrie)
MAGNIFICENT MAGNOLIAS Leading the global conservation of an ancient plant lineage By Jean Linsky
Magnolia wilsonii (Photo: Yang Keming)
With over 300 species, Magnolias are valued worldwide for their beauty, and as sources of medicines and timber. But conservation assessments reveal that 47% of Magnolia species are threatened with extinction; many are subject to habitat destruction, overharvesting and poor natural regeneration. In collaboration with Botanic Gardens Conservation International (BGCI), we are leading the Global Conservation Consortium for Magnolia (GCCM). The goal is to mobilize a network of institutions to develop and implement a comprehensive conservation strategy to prevent extinction of the world’s Magnolia species. The GCCM will bring together global experts, conservationists and botanic gardens to identify and prioritize species of conservation concern, ensure their in-situ protection, increase species and genetic diversity in ex-situ collections, whilst building conservation knowledge and awareness. We have recently held meetings to provide information to prospective consortium members, and are carrying out IUCN Red List assessments for previously unassessed species. We are now working on a conservation gap analysis to understand genetic representation of all current ex-situ collections. Atlanta Botanical Garden is honored to be part of this global initiative ‘to ensure that no wild species of Magnolia becomes extinct’.
Genetic diversity of Apalachicola rosemary
What is Maternal Line Tracking?
How wetland restoration helps save shorebirds
Dear Friends and Colleagues, As we near the end of 2020, I find myself reflecting on all we have endured this past year. As a community we have had to grapple with unprecedented challenges from the devastating pandemic, social injustices, and increasingly urgent threats from climate change. With the sixth global mass extinction event underway and the state of biodiversity and ecosystems at its most perilous point in human history, understanding the challenges imperiled plants face is critical. Recent reports indicate that 2 in 5 of the world’s plant species are threatened with extinction, putting supplies of food and medicines at risk and greatly impacting ecosystem services . Our ecosystems and plants need us now more than ever, to step up and continue the fight to avert the further degradation of these systems and prevent the loss of millions of species. 1
At the Southeastern Center for Conservation, we have been adapting to the pandemic – learning to work from home whilst continuing to maintain and grow our valuable Conservation Collections, and carefully continuing our field research. We have been able to innovate and maintain momentum on key projects including collecting for our Conservation Seed and DNA Tissue Banks, continuing our restoration efforts in Georgia and the panhandle of Florida, establishing a Global Conservation Consortium for Magnolias, and conducting research on key imperiled species across the Southeast. The pandemic has exposed the fragility of modern society, but we must not forget that healthy, biodiverse ecosystems are essential to our existence. There is no going back to the world we left in our now-empty offices, airports, and meeting centers. By rebuilding better, we cannot undo the devastating suffering the pandemic has caused, but we can and should ensure that the future is safer, more resilient, equitable, and sustainable. We will continue to work and partner with amazing collaborators to bring about meaningful change for imperiled plants and ecosystems globally, and we are thankful for your support! Warmest Regards and Best Wishes for 2021,
Emily E. D. Coffey Vice President, Atlanta Botanical Garden Conservation & Research 1. Antonelli, et al., 2020 State of the World’s Plants and Fungi 2020. Royal Botanic Gardens, Kew.
Synecology | Issue 2, 2020 | Southeastern Center for Conservation established 2019, Atlanta Botanical Garden The Anna and Hays Mershon President & CEO: Mary Pat Matheson | Vice President, Conservation & Research: Dr. Emily Coffey Editor: Laurie Blackmore | Design: Loy Xingwen (Visiting scientist, Emory University) Staff and Researchers: Jessica Allen, Ph.D. (Conservation Coordinator, Research Scientist) Laurie Blackmore M.S. (Conservation & Research Manager)
Carrie Radcliffe, M.S. (Restoration Coordinator & Safeguarding Database Manager)
Lauren Eserman, Ph.D. (Research Coordinator, Research Scientist)
Ashlynn Smith (Gulf Coast Coordinator)
John Evans, M.S. (Conservation Horticulture Coordinator)
Jeff Talbert (Project Coordinator, GEBF Florida)
Jason Ligon (Micropropagation & Seed Bank Coordinator)
Rashaad Tillery (Assistant Conservation Horticulturist)
Liz Miller (Field Biologist, GEBF Florida)
Lila Uzzell (Research & Conservation Assistant, Field Biologist)
Emma Neigel, M.S. (Conservation Horticulturist) Have a question? o Contact us at conservation@atlantabg.org or visit atlantabg.org/conservation-research/southeastern-center-for-conservation Follow us on Instagram @atlantabgconservation
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SMALL-WHORLED POGONIA Isotria medeoloides habitat research, population survey (page 11)
HOSTED SePPCon 2020 Southeastern Partners in Plant Conservation conference JOINED SE PCA Southeastern Plant Conservation Alliance (back cover)
VIRGINIA MEADOWSWEET Spiraea virginiana population survey
SE PCA FOOTPRINT
MOUNTAIN GOLDEN HEATHER Hudsonia montana population survey
MIDTOWN INTERNS
9 GAINESVILLE INTERNS
3 DEER LAKE INTERNS
1 PLATANTHERA DIVERSIFICATION Seed & mycorrhizal research with American Orchid Society (page 10)
SEED BANKING / NURSERY POPULATION SURVEY RESEARCH OUTREACH
SEED BANKING Assessing long-term Seed viability (page 9)
MILKWEED CONSERVATION Aslclepias spp. seed collection and safeguarding (page 8)
EXPERIMENTAL SLOTH-BOT Robot installed at Atlanta Botanical Garden to collect environmental data
HABITAT RESTORATION
MATERNAL LINE TRACKING Numerous genera (page 5)
DEER LAKE STATE PARK Restoration of wetlands and coastal dune lake habitat (page 6 – 7)
APALACHICOLA ROSEMARY Conradina glabra population genetics study (More on page 4)
2020 YEAR IN REVIEW
SELECT MEETINGS & CONFERENCES (VIRTUAL) American Public Gardens Association 2020 Conference Botany 2020 Conference Center for Plant Conservation National Meeting 2020 North American Congress for Conservation Biology 2020 Southeastern Partners in Plant Conservation Conference 2020
JOINED NETWORKS Global Conservation Consortium for Magnolia (front cover) Botanical Gardens Conservation International - Advanced Conservation Practitioner Accreditation Voted in as an International Union for the Conservation of Nature (IUCN) Member. IUCN Species Survival Commission - Global Trees, Seed Conservation, & Conservation Planning Specialist Groups
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HILLS APART The spatial distribution of genetic diversity in the endangered Apalachicola rosemary By Lauren Eserman Apalachicola rosemary, or Conradina glabra, is a federally listed endangered species endemic to a small area of upland sandhills east of the Apalachicola River in the Florida panhandle. It is unknown whether plants growing adjacent to one another in the wild represent genetically unique individuals or identical clones – until now. With funding from the USFWS, we performed RADseq genotyping, a technique which allows us to sequence thousands of loci from across the genome of C. glabra. Analyses of DNA from 564 wild plants suggest that genetic diversity in the remaining population is geographically structured, and that the most unique pocket of genetic diversity exists on the most northern sandhill (‘A’ in figure). We also found that individuals growing less than a meter apart are most genetically similar to one another, but still unique, indicating seed rather than clonal reproduction. Knowing the spatial distribution of this species’ gene pool will help us better capture genetic diversity in seed collection trips in 2021.
DIVIDED GENE POOL k=2 k=3
SANDHILLS A -F
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PHYSICAL DISTANCING – To understand how the genetic diversity of C. glabra is distributed across space, we used RADseq genotyping to partition the gene pool into ‘putative subpopulations’. The graphs show how the genetic diversity would be distributed if we were to split the gene pool into two subpopulations (k=2) and three subpopulations (k=3), denoted by color. While these aren’t ‘true’ subpopulations per se, this technique reveals that differences in the genetic makeup of plant individuals increases with geographical distance. The genetic makeup of plants from sandhills A and F are notably distinct. This may hint at the species’ relatively short seed dispersal and/or few pollinators that can facilitate long-distance gene flow.
BABY BLOOMERS A closer look at Maternal Line Tracking By John Evans A primary objective of conservation horticulture is to grow and maintain collections that preserve within-species genetic diversity. When collecting plant material for safeguarding, we strive to include as many individuals as practical from a species’ gene pool. The concept is simple - harvest seed from as many different plants in a population as possible and then plant them – but a more nuanced approach is needed to truly capture and maintain a genetically diverse collection. Research by the Center for Plant Conservation (CPC) and Atlanta Botanical Garden shows that without close monitoring, conservation collections can become dominated by the offspring of one or a few individuals. This is in part because individual plants vary in the number of seeds they produce in any given season. Garden conditions might also favor the offspring of some plants more than others. One way we ensure collections contain a diverse gene pool is through a technique known as Maternal Line Tracking (MLT). In this process we first tag each wild plant from which we collect seed. The seed harvested from each of these ‘mother plants’ is then packaged and processed separately. Throughout the entire process we track how many seeds from each mother plant were collected, were viable, germinated and survived. Knowing the provenance of every seed and plant allows us to maintain collections with even representation of a variety of individuals from the wild. We can then be intentional about subsequent seed collection in the field to maintain genetic diversity in our cultivated populations.
GREEN THUMB – John Evans is the Garden’s Conservation Horticulture Coordinator.
4 STEPS to maintaining within-species diversity with Maternal Line Tracking
Tag wild plants with metal pins and record their health and GPS locations. Give each plant a unique ID number.
Collect seeds and package those from different mother plants separately. Label seed packets with the mother’s ID number.
Process the seeds and x-ray them to assess quality. Sow viable seeds and/or store them in the seed bank (see page 10).
Grow the seedlings until they are ready for maternal line beds. Label each plant and include a reference to its mother’s ID number. Use below-ground partitions to keep individuals separated.
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PLANTS FOR PLOVERS How wetland plant conservation at Deer Lake State Park helps imperiled shorebirds By Ashlynn Smith, Illustrated by Loy Xingwen
1. The Uplands Freshwater falls as rain on the vast uplands. Here, the water quickly infiltrates the deep, sandy soils. The uplands are home to the iconic longleaf pine (Pinus palustris), and beneath their sparse canopies thrives a rich mosaic of flora and fauna. Uplands and wetlands provide habitat for the vulnerable flatwoods salamander (Ambystoma cingulatum).
2. The Wetlands Rainwater flows from the uplands into nearby wetlands, where soils are naturally acidic and nutrient-deficient. A diverse array of low-growing wetland plants thrive here, where they assist with water filtration and reduce the speed of water flow. Wetland plant communities are also adapted for frequent, low-intensity fires that were historically ignited by lightning. Without fire, large woody plants quickly spread into herbaceous wetlands, outcompeting nearly all species as well as altering hydrology.
OUT OF THE WOODWORK – Decades of fire-suppression have allowed large woody plants, such as the buckwheat tree (Cliftonia monophylla) to encroach on wetlands. The trees smother sun-loving wetland plants with their shade, change hydrology with their deep roots, and increase soil nutrients with their leaf litter. The Garden is currently working with the Florida Park Service, U.S. Fish & Wildlife Service and USDA Forest Service to clear woody overstorey from over 300 acres of Florida’s wetlands!
At first glance, the Florida panhandle’s terrestrial wetlands seem irrelevant to its distant coastal habitats and biodiversity, yet they are intimately connected by one thing: water. This infographic explains the vital role that Florida’s wetlands play in stabilizing water quality and quantity from the land to the sea. Healthy interior wetlands help maintain the delicate balance of fresh and salt water in coastal
habitats. In turn, flourishing coastal ecosystems support shore birds and nearby fisheries. But Florida’s wetlands are under threat. In addition to urban development, decades of fire suppression have allowed woody shrubs to spread into herbaceous wetlands. These shrubs displace wetland flora and alter hydrology. At Atlanta Botanical Garden, we are currently working with numerous state and federal agencies to help protect the Florida panhandle’s unique ecosystems.
Plight of the Snowy Plover
3. Coastal Dune Lakes Coastal Dune Lakes are an extremely rare geologic feature and occur in just a handful of locations worldwide - New Zealand, Australia, Madagascar, Oregon and the Florida panhandle. Their waters are a variable blend of fresh and salt water, dependent on the frequency and duration of their connectivity to the Gulf of Mexico.
The snowy plover (Charadrius nivosusis) is a small wading bird about 5-7 inches long. Due to their petite size, breeding plovers conserve energy by nesting close to rich food sources, such as the banks of coastal dune lakes. Populations of this species are declining and irreplaceable nesting habitats are being protected to secure its future.
4. Beach Dunes & Estuary Adjacent to the coastal dune lake and its outlet to the sea, the interface of fresh and salt water supports dune vegetation and wildlife, such as the endangered beach mouse. Beneath the moist sand live a myriad of crustaceans, worms and mollusks, which are important food for shore birds like plovers and terns.
WETLAND WONDERS – There are more carnivorous plants in Florida than anywhere in the country! Pitcher plants, sundews, butterworts and bladderworts thrive in poor, boggy soils by catching insects for extra nutrients. Wetlands are also home to state-listed threatened species, such as the pine lily (Lilium catesbaei) and Chapman's crownbeard (Verbesina chapmanii).
GOT MILKWEED? Safeguarding endangered milkweed species By Emma Neigel
BOGGED DOWN – Emma Neigel and Lila Uzzell ‘bogging’ to collect seeds of red milkweed.
Four milkweed species are critically imperiled (S1) in Georgia: Savanna milkweed (Asclepias pedicellata), Purple milkweed (Asclepias purpurascens), Red milkweed (Asclepias rubra), and Swamp milkweed (Asclepias incarnata ssp. incarnata). Recognizing the importance of conserving Georgia’s critically imperiled milkweed species, the Atlanta Botanical Garden’s Conservation and Research department proposed to collect seed to be grown ex situ, or “off-site” in its safeguarding nursery and seedbank. With support from the Georgia Botanical Society’s Marie Mellinger Field Botany Research grant, Conservation and Research team members, Emma Neigel, Lila Uzzell, and Jason Ligon led multiple collection trips with partners throughout Georgia. The seed will be placed in ex-situ safeguarding collections at the Garden’s conservation safeguarding nursery and seed bank. Special thanks to Berry College, Georgia Department of Natural Resources (DNR), the Nature Conservancy (TNC), Chattahoochee Nature Center, Georgia Power, as well as private land-owners, and local botanists (Richard Ware, Alan Cressler) for their support.
CONSERVATION LEGACIES Conservation scientists of the future By Lauren Eserman Two interns received accolades for their research at the Georgia State Undergraduate Research Conference. Dani Davis and Chazz Jordan were both awarded the GSU Sustainability Award for environmental protection and ecological problem-solving. Chazz was also awarded the William G. Nolan Memorial Scholarship Award for her outstanding academic, research, and leadership achievements. They are both graduating seniors and are moving on to amazing next stages. Chazz has been accepted into the Plant Biology PhD program at the University of Georgia where she will study flowering plant evolution, and Dani will begin studying for her MS degree at Florida State University in the Biology Department, where she will study barrier island and dune plant ecology.
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AWARD-WINNING – Interns Chazz Jordan (above) and Dani Davis (below).
SEEDBANKING RACE AGAINST TIME Monitoring and maintaining seed viability By Jason Ligon
Seed banking is a space-efficient way to store and safeguard plants for extended periods. Our new Conservation Seedbank Laboratory contains seeds of some of the Southeast’s most rare and endangered species. But seeds do not remain viable indefinitely, and we are constantly evaluating techniques extending seed shelf life. For example, the seeds of some plant species last longer in low-humidity environments (called ‘orthodox’ seeds), so we desiccate these seeds before storage to remove excess moisture. Not all seeds can survive desiccation - some may need to be stored in cool, moist and aerated conditions instead (‘non-orthodox’ or ‘recalcitrant’ seeds). MULTIPLY – Jason Ligon is the Garden’s Micropropagation & Seed Bank Coordinator.
Over nearly two decades, the Conservation Seedbank has amassed nearly 1,000 accessions from an impressive array of species. We regularly test seeds from the collection to assess their health and viability. With help from interns and volunteers, we test small subsets of seeds with tetrazolium chloride (TZ test). This chemical stains living seed tissue red, allowing us to estimate what proportion of a sample of seeds remains alive. Alternatively, we may conduct germination trials by growing out some seeds to see what percentage germinate. Through the Southern Seeds Program, high school students from the Atlanta area are helping to meticulously score the results of viability trials. Measuring seed survival and viability is labor-intensive, but crucial to informing seed management for different species. Our recent research shows that for many plants, seed quality does not decline steadily over time. Instead, the quality of seed samples tends to be stable for a given period, before rapidly declining (a reverse sigmoid curve relationship). Understanding such trends allows us to better curate and manage seed quality.
Georgia Oak Quercus georgiana ‘EASY’ TZ – Tetrazolium chloride stains metabolically-active tissue red. Here are magnified seeds of the cigar orchid, Cyrtopodium punctatum.
dead
live
Alabama pitcher plant Sarracenia alabamensis
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THE ORIGIN OF SPECIES Drivers of speciation in North America’s Platanthera orchids By Jason Ligon
There is still much to learn about Platanthera, the most species-rich genus of orchids in North America. One of the factors complicating the identification, classification and conservation of Platanthera is naturally-occurring Platanthera hybrids, which are often intermediate in their characteristics between their parent species. This summer, the Smithsonian Environmental Research Center (SERC) was funded by the American Orchid Society to investigate diversity in the Platanthera genus. This research examines not only established species and hybrids, but also recently described species that may be of hybrid origin. Atlanta Botanical Garden contributed to this research by helping to collect measurements of floral morphology, as well as leaf and root samples, from various wild Platanthera plants throughout the Southeast.
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We will make detailed comparisons of the floral morphology of wild species and hybrids. In addition, we will conduct next generation sequencing on leaf samples, to determine if hybridization is a driver of speciation. Finally, we will identify operational taxonomic units (OTU) of fungal root symbionts (mycorrhizal fungi) from different Platanthera species and populations, to determine if species and hybrid fidelity to specific OTUs help to drive speciation in this orchid genus. As mycorrhizal fungi are usually vital facilitators of orchid seed germination, we will also evaluate fungal cultures in seed germination trials. Understanding the biology and ecology of Platanthera will help us better conserve these unique orchids.
ISOLATED ISOTRIA Monitoring fragmented populations of the Small Whorled Pogonia By Lila Uzzell Small whorled pogonia (Isotria medeoloides) is a terrestrial orchid found in the forests of the eastern United States and Canada. Despite the species’ broad range, populations are small, few, and scattered. These isolated populations are primarily concentrated in New England, Virginia, and the southern Appalachian mountains. Atlanta Botanical Garden is contributing to small whorled pogonia research and conservation in several ways. Since 2019, we have been tagging the location of every known plant in Georgia to closely monitor population health, size, and reproduction. While doing so, we have discovered three extant populations thought to have been lost. We are now collecting small whorled pogonia seeds and plant material for propagation and safeguarding. Since most orchid roots form mutually beneficial relationships with fungi, we are also performing fungal analyses on the roots of small whorled pogonia to identify their vital ecological partners. Finally, an experiment conducted on a New England population suggests that canopy thinning to increase light access may benefit this orchid species - we plan to test this approach for restoring select Georgia populations. We hope to continue partnering with the USDA Forest Service to secure the future of small whorled pogonia populations in the southern Appalachian Mountains. 1
1. Brumback, W., Cairns, S., Sperduto, M., & Fyler, C. Response of an Isotria medeoloides Population to Canopy Thinning. Northeastern Naturalist 18, 185-196 (2011)
TOUGH BEING GREEN – Since 2019, we have found a total of 247 small whorled pogonia plants at 10 sites across Georgia. The species is currently listed by the U.S. Fish and Wildlife Service (‘threatened’), NatureServe (G2 ‘imperiled’) and IUCN Red List (globally ‘vulnerable’).
KEEPING IT LIGHT – Scientists in New Hampshire removed trees and shrubs around a wild population of small whorled pogonia in 1997 (red line). This increased the number of stems and flowers. Source: Ref. 1
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Southeastern Partners in Plant Conservation 2020 The second Southeastern Partners in Plant Conservation (SePPCon 2020) conference was held March 2-6 and was attended by more than 200 people from across the United States. Conference sessions featured experts presenting on the topics of culturally significant plants, management and monitoring, policy and advocacy, private lands conservation, regional initiatives, state-based conservation alliances, and science-based solutions to rare plant recovery. Pre-conference workshops included training in IUCN Red Listing & NatureServe Ranking, Conservation Horticulture, and Seedbanking & Micropropagation. A post conference workshop on resource prioritization provided examples of how to maximize available resources to leverage the most success. Breakout sessions created a forum to share and build skills for collaboration, communication, fundraising, and volunteers. Small-group skills assessment workshops formed the basis for larger group sessions led by a professional facilitator that sought to identify regional needs and how they can be met by a formal regional alliance. We were prompted to consider our biggest challenges and what success could look like for such a collaborative network, including solutions to our shared challenges.
The Southeastern Plant Conservation Alliance The Southeastern Plant Conservation Alliance (SE PCA) is a cross-cutting partnership of public and private conservation professionals working in Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North and South Carolina, Oklahoma, Tennessee, Texas, Virginia, West Virginia, and Puerto Rico & the U.S. Virgin Islands. The SE PCA seeks to bridge gaps between local and national efforts by fostering regional cooperation and promoting a diversity of partners. The Alliance is tailored to multiple interests to provide training opportunities, fill information gaps, identify conservation needs, prioritize efforts, and work collaboratively to conserve imperiled plants. This is achieved by adapting successful models, novel partnerships, and creative solutions to conservation challenges while leveraging shared resources. Virtual, bimonthly meetings began in July 2020 and feature guest speakers followed by planning team discussions. We are currently reviewing immediate goals and organizational models of other collective initiatives so that we can draw upon their experiences in deciding how to best structure our regional alliance.
Synecology is an annual end-of-year publication by the Southeastern Center for Conservation at the Atlanta Botanical Garden. 1345 Piedmont Ave NE, Atlanta, GA 30309