Florida

Dr. Pamela S. Soltis, Founding Director of University of Florida Biodiversity Institute, Distinguished Professor and Curator at the Florida Museum of Natural History

We are living in a new geological era, termed the Anthropocene, in reference to human impact on our planet. This impact has led to extinction rates that are 1000 times higher than background extinction and the view that we are currently witnessing the Sixth Mass Extinction – this one caused by human activities. Climate change is forcing plants to respond to altered temperatures, precipitation, community structure, and more. Although some plant species are able to tolerate these alterations, others are being pushed closer to extinction. Successful conservation requires a multi-pronged approach, with data and tools from diverse sources. The world’s herbaria house nearly 350 million specimens, collected over centuries, and together these specimens hold immense information about plant species habitats and distributions. Through digitization of natural history specimens, this information is becoming increasingly available for modeling, computation, and other analyses. These digitized herbarium data have much to offer the field of plant conservation. For example, ecological niche modeling of rare species can help forecast future distributions and clarify potential future threats. Development of phylogenetic diversity indices for geographic regions of interest can also help identify areas that should be prioritized for conservation based on the distributions and evolutionary history captured regionally. Examples from the Florida flora will be presented to illustrate these new applications for “old” data.

Date Recorded: 
Monday, March 2, 2020

James Lange and Jennifer Possley, Fairchild Tropical Botanic Garden

In the event of a hurricane, low elevation and proximity to the coast place Fairchild at high risk, and thus contingency plans must be in place to preserve our ex situ collections. Anticipating severe damage and extended power loss from Hurricane Irma, we took several measures to protect our conservation collections. We will discuss actions taken by conservation staff and lessons learned from this unique storm.

Contributing Author(s): 
Date Recorded: 
Thursday, May 3, 2018

Cheryl Peterson, Bok Tower Gardens

Dicerandra immaculata var. immaculata (Lakela’s Mint) (Lamiaceae) is a short-lived perennial endemic to the Atlantic Coastal Ridge. It has only a three-mile historical range and few remaining populations. Population modeling predicts near complete loss of plants within eight years unless habitat is improved enough to support large enough populations to withstand stressful events such as drought. Prescribed fire has not been implemented as a habitat-maintenance tool because of the dense urban interface. Regular volunteer workdays have instead been used to eliminate the biggest threats to the persistence of Lakela’s Mint by hand-pulling love vine, thinning the dense overgrowth, and herbicide-treating invasive grasses. A positive response of the mint population, tracked through bi-annual monitoring, is evident. Within one year, plants in an improved area increase in size and reproductive output by ~30%, and seedling recruitment has been observed in long-unoccupied plots. This project shows that regular workdays can be an effective strategy to rebuild Lakela’s Mint populations that are rapidly declining due to loss of quality habitat where implementing fire is not possible.

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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

Sara Johnson, Department of Natural Resources and Environmental Science at University of Illinois: UrbanaChampaign

Brenda Molano-Flores, Illinois Natural History Survey, University of Illinois: Urbana-Champaign

Janice Coons, Eastern Illinois University

Many rare and at-risk species exhibit a paucity of research, leaving gaps in the knowledge required to conserve them. Macbridea alba Chapman (White birds-in-a-nest, Lamiaceae) is a federally threatened and state endangered herbaceous mint restricted to a narrow distribution in the longleaf pine ecosystem of the Florida panhandle. Habitat conversion and destruction are among the primary reasons for Macbridea alba’s decline. Populations are highly fragmented by plantations, clear cuts, or development resulting in extirpation in some areas. Whereas known Macbridea alba populations are primarily found within Apalachicola National Forest, it is uncertain exactly how many exist, and few are documented outside of protected areas. There are many unknowns regarding the ecology of this species; however, previous research suggests that microhabitat differences and disturbance play an important role in its reproduction and survival. Habitat suitability models are a useful tool for gaining insight into the potential drivers of species distribution and persistence on the landscape. These models can define the environmental predictors of occurrence and facilitate the discovery of previously unknown populations. Additionally, these models can guide conservation of areas for potential reintroduction based on habitat conditions and proximity to known source populations. We have created preliminary habitat suitability models using known occurrence records for Macbridea alba as well as open sourced environmental spatial data to identify new areas of potentially suitable habitat. In 2019, field surveys were conducted for the purpose of model verification resulting in the discovery new populations. In the future, models using a disturbance variable such as fire season or time since fire, will be used to determine if the models could be improved. The results from the improved models will help us understand the specific role of fire management and fire frequency on the persistence and survival of this species. Additionally, it will assist us in defining range limits and environmental parameters for Macbridea alba’s distribution and whether it is a candidate for reintroduction or ex-situ conservation efforts.

 

 

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

Brian Pelc, Restoration Project Manager, The Nature Conservancy-Florida. Coordinator of the Apalachicola Regional Stewardship Alliance. Chad Anderson, Ecologist,

Florida Natural Areas Inventory Wet and Mesic Longleaf Pine Flatwoods (and structurally comparable longleaf ecosystems) play a critical role in maintaining the high biodiversity of southeastern forests. Previous flatwoods work has identified as many as 191 vascular plant taxa as well as >1500 plant species endemic to the North American Coastal Plain. This broad region of the southeastern continental United States is home to a gradient of native flatwoods habitats that once covered upwards of 90 million acres from Virginia to Texas. However, the vast majority of these native pine ecosystems were converted to off-site pine plantations and fire excluded in the last century, greatly reducing plant diversity and leaving land managers and biologists uncertain how best to implement and measure restoration efforts within a legacy of ecological mismanagement. Flatwoods restoration approaches in the last decade have resulted in very few successes, largely due to low survival of pine seedlings grown under an uncharacteristically dense and resilient shrub layer. To address this uncertainty and reverse the pattern of failed efforts, a partnership in the eastern portion of the Florida Panhandle is coordinating an effort to test various canopy conversion and fire re-introduction efforts on a meaningful scale and using a common monitoring protocol. The end goal will be a suite of clearing, site preparation, planting, maintenance and monitoring regimes that efficiently restore forest function and facilitate increased biodiversity over time. After identifying knowledge gaps for flatwoods longleaf pine establishment as a significant and high priority obstacle to large scale flatwoods restoration, the steering committee of the Apalachicola Regional Stewardship Alliance (ARSA)identified funds to 1) develop a monitoring protocol useful and comparable across the region and a variety of canopy thinning strategies and 2) install permanent plots in (at least) three partnership properties that span the east-west breadth of the partnership region (~ 100 miles.) Speakers will describe the baseline monitoring effort as well as plot level comparison between traditional vegetation monitoring data and data collected by terrestrial lidar scans. This project will require as much as decade to realize the full suite of tools for reconversion and associated impacts on flatwoods function and biodiversity. However, early successes can inform other projects and refine the suite of available tools.

Date Recorded: 
Wednesday, March 4, 2020

Stephanie Koontz, Archibold Biological Station, Cheryl L. Peterson, Bok Tower Gardens, Valerie C. Pence, Cincinnati Zoo and Botanical Garden, Eric S. Menges, Archbold Biological Station

Translocations are an increasingly utilized tool for rare plant conservation. Urbanization along the Lake Wales Ridge, in southcentral Florida, has led to 85% loss of native Florida scrub and sandhill. The few remaining intact patches hold a plethora of endemics. Our program has translocated several species from unprotected to protected parcels. All translocations are monitored post-outplanting and demographic data used to evaluate success. Here we present case studies for three federally listed species and discuss the challenges in restoring rare plants. Ziziphus celata has few remnant, mostly unprotected populations. Further contributing to its rarity is slow growth and limited sexual reproduction. We implemented 10 translocations between 1998 and 2012. Analyses of vital rates through 2016 determined annual survival of both wild and translocated plants is high (>90%), but growth of transplants is 1/10th the rate of wild plants. Many wild plants flower annually, yet <3% of transplants have reached reproductive maturity. Setting benchmarks for translocation success is challenging when dealing with a slow-growing, reproductively challenged species. Crotalaria avonensis has two protected and one unprotected site. Fruit set is low, requires insect pollination, and seedlings are rare. In 2012, we introduced genetic material from the unprotected site to a protected parcel. Transplants have thrived and expanded through clonal and seedling recruitment, from 84 original transplants to 208 plants in 2019. Germination of sown seeds was also a success (47%) with many surviving, flowering and fruiting. The first decade of this translocation may qualify as a success, but the ultimate test comes in long-term population responses to land management activities and climate change. Dicerandra christmanii has <10 sites, only one is protected. It relies on periodic fire to maintain open sandy gaps within the scrub matrix and persists from post-fire seedling recruitment. We have augmentated (2010) and introduction (2012) populations. Both translocations grew exponentially, but the question remained, were populations demographically viable. Using long-term demographic data from wild plants and integral projection models, we determined vital rates and predicted population trajectories were similar between wild and translocated populations. Wild populations provide a priori knowledge of a species’ basic biology and ecological requirements to inform more successful translocations.

Contributing Author(s): 
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

Brenda Molano-Flores, Illinois Natural History Survey, University of Illinois: Urbana-Champaign, Sara Johnson, Department of Natural Resources and Environmental Science at University of Illinois: Urbana-Champaign, & Janice Coons, Eastern Illinois University

Macbridea alba (Lamiaceae) is a federally threatened and state endangered perennial herbaceous mint. It is endemic to grassy pine flat woods and occupies a range of conditions from wet savannas and sand hills, to disturbed roadsides. Several studies have been conducted to assess genetic diversity, pollinators, breeding system, and seed germination in Macbridea alba. In addition, work associated with seed banking and flowering in relation to fire has only been published in abstract form making replicability difficult and most of this work has been limited to a few populations. Results from these studies point to: 1) low levels of genetic diversity, 2) need for pollinators such as Bombus spp to facilitate gene flow and fruit/seed production, 3) seed germination is high, 4) vivipary occurs, 5) seeds have limited long-term storage capacity and a lack of dormancy, 6) and flowering may decrease as time since fire increases. However, two areas that have not been fully explored are the reproductive success (i.e., fruit set, seed set, and germination) and pre-dispersal seed predation across multiple populations and their role in the long-term persistence of Macbridea alba populations. In 2019, seven Macbridea alba populations within Apalachicola National Forest were visited to better understand the reproductive ecology of the species. At each site, infructescences were collected and fruit set, seed set, herbivory, and pre-dispersal seed predation were documented. Also, information about vivipary, i.e. premature germination of the seed within the calyx, was gathered. Lastly, collected seeds were used to assess seed germination. Our preliminary results are showing variation among populations for all the metrics that have been measured. Based on these findings, we can better understand the life history strategies and reproductive ecology of this rare plant for conservation both in-situ and ex-situ in the future.

Date Recorded: 
Wednesday, March 4, 2020