SePPCon 2024: New & Rare Species Management
SePPCon 2024: New & Rare Species Management
Maintaining population integrity in genetically diverse Erigeron (Asteraceae) populations in Western North Carolina
Anastasia Wilson* (1), Dr. Katherine Mathews (1), Dr. Jacob Heiling (1), Dr. Richard Noyes (2)
(1) Western Carolina University, (2) University of Central Arkansas
The Erigeron strigosus Muhl. Ex Willd (Asteraceae) species complex is composed of late spring to early summer herbs that are widespread in North America. Many populations of this complex are polyploid and apomictic, but studies have identified sexual, diploid populations specializing on glade habitats throughout the southeastern United States, several of which have been described as new species. Two unusual Erigeron populations were recently discovered in Jackson Co., Western NC: one on an olivine outcrop in Webster that displays distinct morphological variation from other E. strigosus, and a second on a high-elevation, mafic rock outcrop in Cedar Cliff. Plants from both populations were confirmed to be diploid and phylogenetically distinct from each other based on nrDNA ITS and ETS regions, and preliminary genetic fingerprints from Amplified Fragment Length Polymorphisms (AFLP) indicate new species status, potentially for each population. The Erigeron population in Webster is located on conservation easement property owned by the Highlands-Cashiers Land Trust and is therefore not at risk of development, however, it is maintained by private homeowners, and ensuring the population is not mowed is essential to maintaining population integrity. Similarly, the population located within Cedar Cliff Preserve is protected and maintained through the NC Plant Conservation Program which restricts access to permit-holders. AFLP data indicate low genetic diversity in Webster and relatively high genetic diversity in Cedar Cliff, potentially due to inbreeding, small population size, and lack of human disturbance. Cooperating with private homeowners to take in-situ action will allow these populations to persist over time.
Locust Pocus: Phylogenetics and Conservation Genetics of Rare Robinia of the Southern Appalachians
Brandon Wheeler* (1, 2), Katherine Mathews (2), Paul Manos (3)
(1) North Carolina Botanical Garden, (2) Western Carolina University, (3) Duke University
Video start time: 8:59
Robinia L. (Fabaceae) is a genus of trees and small shrubs native to North America, with several species that are of conservation concern within the Southern Appalachians. The genus has been re-circumscribed utilizing morphologically based taxonomic treatments several times in the last century, though no molecular study has focused solely on the genus. Two taxa within Robinia, both narrowly endemic to the Southern Appalachians, have variously been treated as species or varieties: Robinia viscosa and Robinia hartwigii. We examined the phylogenetic relationships of these species in the context of other members of the genus in the Southern Appalachians utilizing a robust Restriction Site Associated Sequencing (RAD-Seq) dataset which was then applied to both species group discovery and phylogenetic methods of species delimitation. In addition, our approach sampled several individuals from each population to analyze gene flow and genetic diversity of both focal taxa. Together these analyses present a clearer understanding of the evolutionary history of the genus and the future threats to these rare clonal shrubs of the Southeastern Appalachians.
Assessing Management Options and Population Trends for a Globally Imperiled Shrub (Fothergilla milleri)
Clayton W. Hale* (1), Joshua J. Granger (2), Caleb D. Goldsmith (3), Anna W. Wyngaarden (1), Megan L. DeMarche (1)
(1) Department of Plant Biology, University of Georgia, (2) Department of Forestry, Mississippi State University, (3) Orianne Society
Video start time: 15:58
Fothergilla milleri is a recently described and globally imperiled shrub endemic to the Gulf Coastal Plain of Florida, Alabama, and one county in Georgia. Recent work has shown the majority of known individuals are within one population in Alabama, indicating the species is likely vulnerable to stochastic events, inbreeding depression, and other threats linked to small, concentrated populations and distributions. Furthermore, evidence suggests a newly described aphid species (Hamamelistes blackmani) reduces sexual reproduction across the range of Fothergilla milleri to nearly zero. Lastly, it is hypothesized that Fothergilla milleri is at risk of being shaded out by overstory competition due to a lack of a natural fire regime within its habitat. Currently, it is unclear how these, and other anthropogenic threats such as climate change, will affect the long-term viability of Fothergilla milleri populations. From 2020-2024, we performed exhaustive, 100% inventories of all ramets within the two largest known populations of Fothergilla milleri. Furthermore, various management activities, including prescribed burns and mechanical thinning, have occurred within the monitored populations. Here we present the four-year population trends in Fothergilla milleri along with the impact of various land management treatments on population growth. Understanding how management options may impact population growth permit land managers and conservationists to make better informed management decisions to ensure the sustainability of Fothergilla milleri on the landscape.
Climate modeling for coastal rare Florida endemic Hymenocallis henryae populations and the implication for conservation and management
Maria Vogel* (1), Vivian Negron-Ortiz (2, 3), Richard Moore (3)
(1) The Nature Conservancy, (2) USFWS, (3) Miami University of Ohio
Video start time: 23:32
Hymenocallis henryae is a rare, charismatic spider-lily endemic to the Florida panhandle. Currently under review to determine if listing under the Endangered Species Act is warranted, this species has undescribed genetic diversity, information crucial to the listing process. We conducted field observations of 21 historic populations across the species’ geographical range and performed genomic analyses of 279 individuals from 19 extant populations. Most populations had fewer than 40 individuals, while populations with >100 individuals were found exclusively on managed lands. Genetic diversity was uniformly low within populations (HE: 0.074- 0.093), with low to moderate inbreeding coefficients (FIS: 0.068-0.431). Genetic differentiation was relatively low among most populations (FST: 0–0.098), although there was statistical support for isolation by distance. In addition, we found high genetic similarity and lack of population structure across the species range. We confirmed current threats (habitat change, residential development, fire suppression) and identified several coastal populations threatened by sea level rise. Known as one of the five biodiversity hotspots in America, the panhandle of Florida has many coastal endemics that are threatened by sea-level rise and climate change. It is recommended to continue with in situ protection and management as well as establishment of ex situ living collections to preserve populations most at risk of extirpation from habitat loss and degradation.