federally listed

Lauren Eserman, Atlanta Botanical Garden

Conradina glabra, or Apalachicola rosemary, is a federally listed endangered species that exists only on a small area of sandhill in Liberty County, Florida. Forestry practices in the last 100 years have resulted in declining populations of C. glabra. In the wild, plants produce very few seeds, but small plants that resemble seedlings are commonly found. Through a grant from the US Fish and Wildlife Service, we are using molecular genetic techniques to understand whether C. glabra is reproducing clonally or via sexual reproduction as well as what factors encourage seed germination. To address this question, we sampled plants from forty locations across Torreya State Park in a spatially explicit experimental design. A plant in the center of a large cluster of individuals was marked and samples were taken from plants in all four cardinal directions from the central plant at designated distances. From these samples, we generated RADseq data resulting in >10,000 SNPs from 564 individual plants. Analyses are still ongoing, but early results point to spatially structured genetic variation. Individuals share highly similar genotypes at distances < 1 meter; however, are genetically distinct at distances greater than 1 meter. These results suggest that Conradina glabra is perhaps clonal at very small geographic scales but is generally reproducing sexually across its range. Furthermore, we identify areas with unique genetic variation that is important for conservation. The results of this study are being communicated to land managers who are tasked with preserving this species on the ground.

Date Recorded: 
Friday, October 9, 2020

Sabine Wintergerst, Fairchild Tropical Botanic Garden

The only known remaining populations of the Keys partridge pea (Chamaecrista lineata var. keyensis) are found within the imperiled pine rockland habitat on two islands of the Florida Keys. Like other low-lying islands, the Florida Keys are especially threatened by sea level rise. As a consequence, soil salinity levels will likely rise as well, first in areas closer to the coast but eventually salinization will also reach areas further inland. Additionally, more frequent and higher storm surges are also predicted which will temporarily inundate part of the islands in saltwater. Previous research has shown that the impact of 2005’s Hurricane Wilma negatively affected populations of the Keys partridge pea. However, the effect of increased salinity on seed germination and seedling establishment has not been investigated. We established an ex situ collection through which seed bulking provided enough seeds to use for experimental trials which were conducted with the help of high school students as part of Fairchild’s BioTECH internship program. The results show that seed germination remains high at low levels of salinity (<10ppm) but decreases substantially when salinity becomes more similar to ocean water (~30ppm). Although seedling survivorship is also high at low levels of salinity (<10ppm) it is important to note that even at 5ppm, 20% of seedlings died within 2 months of exposure. Above 20ppm, seedling survivorship declined rapidly revealing how even short exposures to ocean water could have detrimental effects on juvenile plants. Our results show how seedlings are especially threatened by storm surges, but further research is needed to investigate how well seeds and seedlings can recover as soil salinity is alleviated by precipitation. Knowing how these critical life stages of the Keys partridge pea are affected by an increase in salinity can inform the future population trajectory and help with management and/or restoration planning.

Contributing Author(s): 
Date Recorded: 
Friday, October 9, 2020

R. Todd Engstrom, Tall Timbers Research Station and Land Conservancy

The Miccosukee gooseberry (Ribes echinellum) was discovered in on private land in Jefferson County, Florida, in 1924. A second population was located in McCormick County, South Carolina, in 1957, but this is a study of the Florida population only. The species was classified as federally threatened in 1985. A portion of the Florida population was monitored from 1992 to 2001 by The Nature Conservancy and intermittently from 2010 to 2016 for the USFWS. Florida Natural Areas Inventory ecologists mapped the general distribution of Ribes in Jefferson County in 1985. A resurvey of the same area in 2016 determined that gooseberry still occurs to the same extent 31 years later. Ribes appears to thrive in tree fall gaps. Some of the most productive plants, in terms of the number of fruit produced, and some of the densest patches of gooseberry occurred along trunks of large fallen trees. Fruit production in the gooseberry is rare (median number of clumps with fruiting stems was 1.4% for the two subpopulations from 1992-2001), but the species is still common in the small area where it was first described. In 2010 I estimated that there were 8600 gooseberry clumps in the two largest subpopulations, but how clumps relate to genets is unknown. The population trend of gooseberry in one of the two largest subpopulations indicated by transects declined by 14.2% from 2011 to 2013, and nearly every transect in the subpopulation declined from the 10-year average collected from 1992 to 2001. Recent genetic studies revealed low genetic variation suggesting an increased risk of extinction or population decline, and another recent study indicates that seed predation by a mouse could have a significant negative effect on seed dispersal. One hypothesis for local declines of Ribes is rapid growth of extremely dense stands of laurel cherry (Prunus caroliniana).

Date Recorded: 
Thursday, March 5, 2020

April Punsalan, U.S. Fish & Wildlife Service

April Punsalan describes work that Jason Ayers has done with the South Coastal Program in South Carolina protecting and restoring wetland ecosystems.

Date Recorded: 
Thursday, March 5, 2020

Amy Jenkins, Florida Natural Areas Inventory

Chad Anderson, Florida Natural Areas Inventory

Jason Drake, United States Forest Service

Understanding the historic conditions and habitats in a region is a vital first step to planning restoration and management activities. With our partners, US Forest Service, Florida Forest Service, and the Florida Fish and Wildlife Conservation Commission, the Florida Natural Areas Inventory (FNAI) used aerial photography from as far back as the 1930’s, coupled with current photography, soils data, LiDAR elevation data, rare plant occurrences, and GPS’d groundtruthing points, to develop an historic vegetation map of several large contiguous conservation lands in the Apalachicola region. These maps cover a large portion of the region and are an important baseline for ecological and hydrological restoration efforts by managers across property boundaries. Additionally, historic vegetation maps can be used on a smaller scale when planning silvicultural projects, targeting specific habitats for rare plant surveys, or to identify areas where fire has long been absent. This map has been a vital tool when studying rare plant species such as Harper’s beauty (Harperocallis flava). Harper’s Beauty is a critically imperiled, federally endangered plant that is endemic to the Florida panhandle and grows in the species rich pitcherplant prairies of the Apalachicola River lowlands. FNAI has been documenting its populations for more than a decade. Harper’s beauty thrives in a fire dependent habitat that in recent decades has seen a reduction in the fire application and hence an increase of woody vegetation cover and some populations have been reduced or lost. Most recently we established monitoring plots to attempt to quantify its habitat conditions, especially in relation to fire. Preliminary data analysis has provided valuable insight to help guide management.

Date Recorded: 
Wednesday, March 4, 2020

Shawn C. McCourt, Sally M. Chambers, and Bruce K. Holst, Marie Selby Botanical Gardens

The genus Harrisia (Cactaceae) comprises 20 narrowly endemic species of night-blooming cacti with two widely separated geographic ranges, including South America south of Amazonia, as well as the West Indies and southern Florida. Commonly known as aboriginal prickly-apple, H. aboriginum is a sprawling, multi–stemmed, columnar cactus endemic to ancient native American shell mounds, as well as coastal berms, coastal grasslands, and maritime hammocks in four counties along the southwest coast of Florida. This federally-listed species is in steep decline, primarily due to the development of beachfront property, invasive species dominance, and the erosion of coastal barrier islands. Some populations have disappeared entirely. Researchers at MSBG have been conducting an inventory of extant populations, assessing the health of each population, and determining what genetic variation (if any) occurs across the species’ geographic range. When possible, a small portion of seed has been collected for seed banking and to grow plants for the augmentation of shrinking populations and introduction to ecologically suitable sites situated above projected rises in sea level. To date, we have visited nine sites and collected detailed demographic data for 89 plants. Spines were collected from all 89 plants for DNA extraction and the testing and developing of microsatellite loci. Seeds from seven fruits were collected from three sites. Data presented represent the preliminary findings of our work, which has a focus on the importance of maintaining genetic diversity in ex situ collections for the purpose of rare plant conservation.

Contributing Author(s): 
Date Recorded: 
Wednesday, March 4, 2020