Recovering Rare Species
Fairchild plays an important role in the conservation of South Florida's endangered plants through our research with rare plant introductions. We have the combination of factors needed to carry out reintroductions: horticultural facilities, a large base of volunteer labor, and scientific expertise. Fairchild maintains conservation collections to conserve and augment natural populations of endangered and threatened species. Within the past two decades, we have conducted 32 reintroductions of 11 species, in collaboration with land managers at our partner agencies. We design some reintroductions as experiments, so that while we are returning a native species to a natural area, we are also learning about its ecology and biology. Please read about some of our specific plant reintroductions below.
Beach jacquemontia (Jacquemontia reclinata)
Plants that occur within dune habitats are subject to many environmental factors: wind, salt spray, storms, etc. These factors help to naturally select plant species that grow in these conditions. Before starting any experimental outplanting it is first important to understand suitable habitat and conditions for the plants. Fairchild worked with several of our conservation partners at the Florida Department of Environmental Protection to conduct an outplanting of the federally endangered Jacquemontia reclinata along a dune gradient where plants were planted at different distances from the ocean to determine the ideal distance for optimal survival. Results showed that plants in plots closest to and farthest away from the ocean experienced the most mortality. Plants within middle (20-45 m from high tide line) plots showed survival rates of 91%.
Crenulate leadplant (Amorpha herbacea var. crenulata)
The federally endangered species Amorpha herbacea var. crenulata is endemic to (only found in) Miami-Dade County. In the past ten years, habitat destruction has eliminated over half of the wild population and reduced its range to a handful of preserves. In 2002, 2006, and 2007, Fairchild worked with partners at Miami-Dade County's Natural Areas Management and Florida Department of Transportation to perform experimental outplantings of Amorpha herbacea var. crenulata. To date, we have planted over 400 individual plants and several hundred seeds in two separate preserves. Our outplanting experiments have focused on the ideal propagule type (seedling, rooted cutting or transplant) for outplanting, the species' habitat preferences, and the effects of plant litter on seed germination and seedling establishment.
Sargent's cherry palm (Pseudophoenix sargentii)
Pseudophoenix sargentii is an endangered species known from one population in Florida and other locations in tropical Caribbean coastlines. Fairchild plant scientists established conservation collections to augment the wild population and introduce the species to appropriate habitats. Working with National Park Service and the Florida Department of Environmental Protection, we introduced seedlings and juvenile plants to nine locations from 1991-1994. Overall plant survival has been good at six of nine locations. Fairchild and the Florida Department of Environmental Protection continue to monitor the transplants and compare their growth and survival to the wild population. Because these plants are very slow growing and long-lived, none have reached reproductive maturity yet.
Goatsfoot passionflower (Passiflora sexflora)
Goatsfoot passionflower (Passiflora sexflora) is a tropical species whose global range include a handful of parks in Miami-Dade County. We conducted a reintroduction program for Passiflora sexflora in 2004-2006 that was possible only through the cooperative efforts of four different agencies, one private homeowner, and several volunteers. The reintroduction program included surveying for and collecting wild plants, nursery propagation, and reintroduction of 106 plants to a locations within the historic range of goatsfoot passionflower. Reintroductions tripled the known population size of this species in Florida. Early results show that 90% of transplants have survived to date, with more than one-third of these reproducing.
Hammock shrubverbena (Lantana canescens)
Lantana canescens is a rare tropical shrub native to the ecotone between pine and hardwood forests in Miami-Dade County-- a habitat that has almost disappeared. In 2005, we worked with Miami-Dade County and dozens of volunteers to conduct an experimental outplanting of Lantana canescens. Our goal was to prevent extinction of this species in Florida while learning important information about its habitat requirements. We planted 346 Lantana canescens in three Miami-Dade County sites with varying light levels. Our short-term findings show that light is very important for seedling recruitment. While sites with partial sun had little to no seedling recruitment, the site in full sun had 267 new seedlings appear within 18 months of the planting.
Coral hoary pea (Tephrosia angustissima var. corallicola)
Reintroductions can best conserve a rare species if they are conducted in an experimental context so that information about the species' biology can be maximized at the same time. In this light, Fairchild worked with the USDA and Miami-Dade County Dept. of Environmental Resources Management to conduct an outplanting of Tephrosia angustissima var. corallicola into a pine rockland in 2004. Because this species is known only from a single population in a cultivated field, the outplanting was designed to test the suitability of three natural microhabitats for maximum plant growth, survival, and population viability. Initial results indicate that whole plant survival is greatest in partial shade, yet seedling establishment is greatest along roadsides.
Semaphore cactus (Opuntia corallicola)
Known from only two locations in the Florida Keys, the endangered Opuntia corallicola is threatened by low genetic diversity, low reproduction and an exotic moth, Cactoblastis cactorum. Fairchild Tropical Botanic Garden has provided propagules to researchers from the University of South Florida, the Florida Department of Environmental Protection, the U.S. Department of Agriculture, and The Nature Conservancy for research, augmentations, and introductions of new populations in historically appropriate and protected habitats. Plants are surviving best in relatively open hammock.