The mission of South Carolina Plant Conservation Alliance is to coordinate rare plant conservation activities in the state to ensure no local extinctions.
SCPCA is a coalition of partnered organizations and individuals dedicated to preserving South Carolina’s rare flora. The SCPCA initiates and coordinates cooperative conservation activities that will halt or reverse declines in rare plant species, restore ecosystems, and increase plant awareness in the state via education and outreach.
South Carolina: Plant Diversity and Dangers
The southeastern U.S. supports 33% of the total number of plant species in the United States on just 17% of the land mass. South Carolina alone is home to over 3000 vascular plant species, an extraordinary amount of species richness for a relatively small state. A large number of these plants grown in hot spots of biological diversity such as rock outcrops, cataract and southern Appalachian bogs, sandhills, cove forests, relict prairies, and remnants of the Longleaf Pine ecosystem.
Many of these species and communities are endangered. There are 22 federally listed and 34 at-risk plant species in South Carolina. The South Carolina DNR in 2014 listed nearly 450 vascular plants as rare, threatened, or endangered. Many of these are rare because their entire communities are threatened; Carolina bays, coastal sand dunes, rocky shoals, Piedmont seepage forests, cedar swamps, and bottomland hardwood communities have all been reduced to fragments of their pre-development incarnations.
Extinction rates for plant species are seven times greater than for animals. BGCI estimates that there are about 400,000 species of plants in the world and that one in five of these are threatened with extinction. Threats include habitat loss and degradation, competition with introduced invasive species, overexploitation, and climate change. As of September 2017, the U.S. Fish and Wildlife Service listed 945 plants as endangered or threatened in the U.S. The IUCN Red List included 12,253 plants assessed at least Vulnerable.
The SCPCA’s goal is to ensure that rare plant populations remain extant and not extirpated. To achieve this goal, we connect university programs, botanical gardens, government agencies, land managers, environmental consultants, and botanical experts to facilitate collaboration and coordination of statewide plant conservation activities.
Guidelines for Conservation Horticulture
Like zoos with captive breeding programs, botanical gardens face several problems associated with ex situ collection, including small population sizes, genetic drift, spontaneous hybridization, and inbreeding depression. Gardens working in ex situ conservation and hoping to re-establish wild populations must ensure that ex situ collections contain as much genetic diversity as possible.
The SCPCA conducts its in situ and ex situ activities in accordance with well-established integrated plant conservation guidelines.
Sources for these guidelines include governing plant conservation organizations such as:
- Botanic Gardens Conservation International (BGCI)
- Center for Plant Conservation (CPC), including its reintroduction guidelines
- International Union for the Conservation of Nature (IUCN)
- Convention on Biological Diversity (CBD)’s Global Strategy for Plant Conservation (GSPC)
- The Nature Conservancy
- The Society for Ecological Restoration International
There are a number of publications written on plant conservation, including A Handbook for Botanic Gardens on the Reintroduction of Plants to the Wild (BGCI, 1995), the New England Plant Conservation Program (Brumback, 1992), Ex Situ Plant Conservation, Supporting Species Survival in the Wild (Guerrant, Haven, and Maunder, 2004), Genetics and Conservation of Rare Plants (Falk and Holsinger, 1991), Principles and Practices of Plant Conservation (Given, 1994), and Restoring Diversity: Strategies for Reintroduction of Endangered Plants (Falk, Miller, Olwell, 1996).
In situ conservation: maintaining endangered organisms or germplasm in their natural environment.
Ex situ conservation: maintaining actual organisms or germplasm such as seeds in sheltered environments away from their natural habitats, such as growing plants in a botanical garden or keeping animals in a zoo.
Safeguarding: propagation and/or outplanting activities that constitute a conservation strategy of last resort, specifically ex situ or in situ efforts including re-introductions, augmentations/enhancements, and introductions.
Ex situ safeguarding collections: indexed collections of plants, seed banks, and germplasm of known provenance at botanical gardens, arboreta, nature museums, etc.
In situ safeguarding collections: collections of plants that have been deliberately placed in a natural habitat, including augmentation, reintroduction, or introductions.
Introduction (a.k.a. establishment, experimental) – controlled placement of plants into an area where the plant is currently absent and historically unknown.
Augmentation (a.k.a. enhancement, reinforcing) – the addition of plants to an existing population, with the aim of increasing population size or diversity, and thereby improving its viability.
Reintroduction – the process of placing plants back into formerly occupied habitat or into suitable habitat within the plants’ natural range.
Rescue: the relocation of plants that are scheduled for imminent destruction, such as plants on a site slated for development.
SCPCA Conservation Guiding Principles
Maintaining viable populations in their natural habitats is the best way to conserve rare and endangered plants. Further, for federally listed plant species, the intent of the Endangered Species Act is “to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved.” Controlled propagation is not a substitute for addressing factors responsible for an endangered or threatened species’ decline. Therefore, our first priority is recover wild populations in their natural habitat wherever possible.
When in situ conservation is not feasible, safeguarding strategies such as reintroduction, introduction, augmentation, safeguarding ex situ, and rescue can prevent the decline of existing populations or restore lost populations to suitable habitats within their historical range.
The SCPCA will obtain all required permits for collecting, reintroduction, introduction, augmentation, and rescue, and will obey all state and federal guidelines while working with rare and endangered plant species.
Landowners are seen as partners and their participation and support for a project is vital for its success. The SCPCA will obtain landowner permission before collecting material or implementing any horticulture conservation projects on private land.
The SCPCA follows the Center for Plant Conservation’s Seed Collection Guidelines.
- Collect only 10% of seeds in 10% of years for any single population (the 10/10 rule.) Collecting 50% of seeds in 50% of years (the 50/50 rule) is likely to drive a population to extinction.
- Collect from up to 50 populations of each species. If there are fewer than 50 populations, collect from as many as possible.
- Collect first from the largest and most secure populations.
- It is better to collect fewer seeds from many populations than many seeds from fewer populations.
- Space collections over time and years.
- Collect up to 50 individuals from each population. If there are fewer than 50 individuals, collect from 10 percent each year and attempt to collect from all individuals over time. Use a random sampling method to obtain an even sample.
- Collect up to 20 propagules (seeds) per individual, up to 10% of total seed produced by the population in a given year.
- Put the seeds from each individual in its own envelope. Keep seeds cool and dry.
These collection guidelines may be modified depending on a species’ type of breeding system and the distribution of genetic diversity within and among populations.
All collections are carefully documented and the data maintained so that provenance is known. Documentation of provenance includes voucher specimens, formal plant records and accessioning systems, and special plant labeling to track indexed plant material.
Plants without proper provenance documentation are suitable for education and display only. Plant material from educational displays is valuable for safeguarding in the extreme situation that all other surviving plant material in situ and ex situ has been lost.
Plant material is not reintroduced to a population unless it comes from that original population or unless a special breeding project is necessary for the survival of a species. Plant introductions in situ for safeguarding are created within the historical range of the species but not within breeding range of other viable populations of that same species.
Reintroduced and introduced populations in situ are deemed experimental with no long-term guarantee of survival. Until a population is self-sustaining (actively reproducing with evidence of seedling recruitment) it is not deemed successful and contributing to the survival of the species as a whole.
Site location and landowner information is kept confidential to protect wild populations of rare plants.
Plant rescue operations are a strategy of last resort, when a population is clearly doomed to destruction and with the property owner’s permission. Collaborating with the landowner to protect the plants in situ is preferable. If rescue is attempted, removing propagules is preferable to removing whole plants.
The SCPCA chooses plant safeguarding and restoration projects on a case-by-case basis. All decisions for restoration and safeguarding projects are deliberated and documented in writing.
Criteria for Release of Plant Material In Situ
A successful restoration or safeguarding project requires detailed knowledge of a species’ survival requirements.
Sites for in situ conservation/recovery projects are chosen based on the following criteria:
Conservation Status: Is the site protected by state or federal categories of ownership, land trust, or conservation easements? Do we have landowner permission to visit the site when needed? Is there a long-term commitment from the landowner to secure the site and the project?
Accessibility: Will the site reasonably accommodate equipment and plant material transport, and return visits for monitoring and management? Conversely, will the site be readily accessible to people who might tamper, tramp, or take plants from the site?
Appropriateness: Does the site meet the needs of the species (soils, hydrology, light, aspect)? Are there factors (land for purchase, invasive species, effluent or erosion, feral animals, dual land use) that might render the site unsuitable?
Restoration: Many sites require restoration before safeguarding material can be introduced. This may take several growing seasons.
Plant material health and preparation
When placing plant material in situ, the SCPCA takes great care not to introduce any pests or pathogens. Only healthy plants free of any signs of disease, fungal infections, or pests may be outplanted. Roots are washed clean of potting soil before plants are transported to the field to prevent greenhouse weeds or soil pathogens from being introduced in situ.
The SCPCA uses a variety of techniques to help plants establish in situ.
Water: Members will hand water plants weekly or more frequently when plants are first placed in the field, although plantings are usually performed in the dormant seasons, in order that newly placed plants are not unduly stressed by heat or drought. Plants placed in wetlands generally require no additional water. Species established in other habitats may require watering initially until their roots become established. If the source of the water is a concern, The SCPCA may use distilled water or natural water from a nearby source.
Cages: Cages and simple fencing can be used to exclude animals that might disturb the plants before they are established. These can be removed from the site when they are no longer necessary.
Erosion controls: Ideally, plants will not be placed in a site with an existing erosion problem. If necessary, however, silt fencing can protect plants from washing away before they are established. On-site natural materials such as logs, branches, and rocks to help slow and spread water might be preferable.
Labels: The SCPCA may discreetly mark a planting site with flagging tape and may mark planting sites for individuals with some sort of plant label to help relocate the plants when monitoring. Stainless steel photo stakes to mark photo points for establishing long term photo monitoring of a site may also be used.
Chemicals: Chemicals such as herbicides, fungicides, and fertilizer in situ may be required for specific projects. Their use should be avoided if at all possible. Always get landowner permission before introducing chemicals on site.
Active management of introduced plant material is required until a site is self-sustaining. SCPCA members are often directly involved in the management of their in situ projects, but the SCPCA will transfer responsibility to another party as long as active management in perpetuity is guaranteed.
The SCPCA monitors all in situ projects at least annually, more frequently when projects are newly established. Monitoring techniques can include photo monitoring, mapping, vegetation sampling (species richness, percent woody cover), and population surveys (from formal counts to a variety of sampling methods). Trained volunteers living near an in situ project are essential to regular site visits during such critical times as flowering and fruiting, or during droughts or other potentially damaging conditions.