Restoration Potential: Headway for the recovery of this species has been made along several fronts. A number of sites are owned and protected by various groups and agencies. The Nature Conservancy is protecting the sole Tennessee site with a conservation easement. The Michigan Nature Association owns two sites (USFWS 1988, Crispin 1984). The New York State Park system owns two sites. The U.S. Forest Service owns one site within the Hiawatha National Forest in Michigan, while the U.S. Fish and Wildlife Service owns two sites in Alabama (USFWS 1988a). Several states (Michigan, Tennessee and New York) restrict the take of the species under State law (USFWS 1988a).
Recovery of the species through artificial propagation has been studied in the past. Dr. Ralph Benedict of the Brooklyn Botanical Garden was apparently able to propagate individuals from spores (House 1934, Benedict 1925). Spores were sown in 8- inch pans and produced excellent germination rates (Benedict 1925). Hunter (1934) stated that she was able to successfully grow plants which produced sori in a period of five months under greenhouse conditions. Spores were sown on several types of culture media and were easily germinated. She noted, however, that records indicated poor transplantation success for the species.
Successful transplantation of individuals does not appear to be easy. Transplantation was first attempted within Clark Reservation State Park in New York in 1900, when several plants were moved to a ravine a short distance away (Faust 1960). These apparently died. In 1925, an entire population was moved in order to avoid destruction from a quarrying operation (Cinquemani et al. 1988, House 1934, Hunter 1934). The transplants (roughly 400 individuals) initially flourished, but many did not survive beyond 1935 (Cinquemani et al. 1988). Individual plants were apparently able to survive transplanting, but were not able to reproduce (Faust 1969), suggesting a very specific habitat requirement for the species. A small population with origins in New York state still persists in New Jersey as the result of a 1936 transplantation effort.
The U.S. Fish and Wildlife Service has stated that the hart's- tongue fern will be considered for delisting as a federally threatened species when there are at least 13 self-sustaining populations (2 in Alabama, 2 in Tennessee, 3 in Michigan and 6 in New York) under adequate protection (USFWS 1990). A self- sustaining population is a reproducing population that is large enough to maintain sufficient genetic diversity to enable it to survive and respond to natural habitat changes. Populations must also be sufficiently large area to ensure that isolated natural events do not pose a risk to the population, and that management of the site to maintain suitable habitat is minimal.
Preserve Selection and Design Considerations: Adequate land protection must take into account the immediate land upon which the hart's-tongue fern grows, as well as the buffer lands immediately surrounding the population. At sites which include sinkholes or are influenced by rivers, upstream watersheds should be secured to prevent deterioration of water quality and species habitat. Logging, physical disruption of soil and other associated events should be disallowed in the immediate vicinity of Asplenium scolopendrium var. americanum (Phyllitis scolopendrium var. americana) populations.
Management Requirements: In the northern portion of its range, occasional clear-cutting has been suggested as a management technique for Asplenium (Phyllitis) scolopendrium, as most of the known populations in Michigan and New York occur in cut-over second-growth forests (Henson 1978). Ballard (pers. comm.) stated that maintenance of secondary growth, young-to-medium aged mesic forest canopy was a management requirement for the species in Michigan, while cutting of encroaching conifers and hardwoods was proposed as a necessary management tool in New York (Cinquemani et al. 1988). Although excessive shade may be damaging to hart's-tongue populations, excessive sunlight may lead to desiccation and the failure of spore germination and subsequent growth (Cinquemani Kuehn and Leopold 1990b). As a result, clear-cut logging is not considered to be a viable management alternative. If future research indicates the need, selective thinning of forest canopy may be considered.
Management of lands for ground-layer bryophytes apparently will also benefit sites with Asplenium scolopendrium var. americanum (Phyllitis scolopendrium var. americana). Thinning of shrubs from selected sites may reduce overall germination of spores and initial sporeling development, but may increase the long-term survival of hart's-tongue individuals. Again, information pertaining to the appropriate levels of thinning are needed.
Discouraging the poaching of individual plants is another management need for the species. Among fern fanciers, the hart's-tongue has always been a prized species. This may be partially a result of the enormous amount of publicity that has been reaped upon the species in the last century. In any case, precise locations of extant populations should be kept confidential if illegal fern removal is considered a significant threat.
According to the USFWS technical draft recovery plan for P. scolopendrium var. americana (USFWS 1990), the determination and implementation of management practices for long-term reproduction, establishment, maintenance and vigor are essential. Since very little is known about the management of the species, information regarding basic life history, population biology, genetic diversity and ecology is needed prior to implementation of any management guidelines. Management needs include: (1) determination of size and stage-class distribution for all populations, (2) determination of abiotic and biotic features of occupied habitat, (3) long-term demographic studies, (4) determination of genetic variability between populations, (5) determination of effects of past and on-going habitat disturbance, (6) definition of criteria for self-sustaining populations and determination of size of area needed to protect each population.
Before any type of management should take place, the specific requirements of Asplenium scolopendrium var. americanum (Phyllitis scolopendrium var. americana) at each site should be analyzed. Canopy thinning if deemed appropriate, should not be excessive. In the case of the hart's-tongue, insufficient thinning would prove to be far better than being excessive. Excessive thinning may lead to desiccation of habitat and the deterioration of extant populations. In any case, full scale thinning efforts should not be undertaken prior to experimentation of the effects of thinning on a smaller scale.
At sites where populations occur in sinkholes, management must restrict the amount of usage of such cave entrances by spelunkers or other users. Trampling and alteration of natural vegetation appear to be the primary threats at these sites.
Management Programs: The Tennessee Chapter of The Nature Conservancy recently (1982) purchased a conservation easement from a cement company to protect the sole Tennessee population (Somers pers. comm., USFWS 1989b). Consequently, the site has been protected from quarrying and other potentially destructive acts. Contact: Paul Somers, Tennessee Department of Conservation, Ecological Services Division, 701 Broadway, Nashville, TN 37203. Telephone No. (615) 773-6545.
The vast majority of plants in New York occur within a single State Park. Managers of the park are aware of the populations and are cooperating in its protection (USFWS 1989b). Two additional New York populations occur within another State Park, but trail construction in the 1950's and subsequent erosion has eliminated many of the plants (USFWS 1988a). Located within state parks, legal protection is provided to these populations from picking and habitat destruction (Cinquemani Kuehn and Leopold 1990b). Contact: Dianne Wheelock, New York State Office of Parks, Recreation and Historical Preservation, Central Region, Jamesville, NY 13078. Telephone No. (315) 492-1756.
Sites possessing two populations in Michigan have been purchased by a non-governmental conservation organization specifically to provide better protection for the species (USFWS 1989b). Contact Michigan Natural Features Inventory for contact information.
One Michigan population (approximately 25 plants as of 1988) occurs on U.S. Forest Service land within the Hiawatha National Forest. Managers of the forest have rerouted a trail that traversed the population in hopes of reducing impacts on it (USFWS 1989b). Otherwise, no active management is taking place. Since the population at this site is fairly large, efforts have been shunted towards other projects at this time. Management will likely follow successes reached by other management programs. Contact: Jan Schultz, Plant Ecologist, Hiawatha National Forest, 2727 N. Lincoln Rd., Escanaba, MI 49829. Telephone No. (906) 786-4062.
The Alabama population occurs on U.S. federal land. At present, no active management for the hart's-tongue is occurring at the site due to the precarious status of the population. The American Speleological Society issues permits to spelunkers wanting to enter the sinkhole at this site. Consequently, access is somewhat restricted. Contact Alabama Natural Heritage Program for contact information.
Monitoring Programs: Periodic censuses of hart's-tongue populations at a site in New York have been conducted since 1916 (every five years since 1936) by students at Syracuse State University (Cinquemani et al. 1988, Faust 1960). Stem counts of populations are conducted by groups of volunteers sweeping the talus fans from bottom to top, typically during the late fall or early spring, when taller vegetation is not present. Since 1988, all populations within the state of New York have been monitored. There are plans to continue this effort indefinitely. Contact: Dr. Donald Leopold, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210. Telephone No. (315) 470-6784.
The Tennessee population has been intermittently monitored since 1898 when roughly 200 plants were observed (McGilliard 1948). Although numerous counts were made of this population since that time, no counts have been made since 1980 (Somers pers. comm.). Contact: Paul Somers, Ecological Services Division, Tennessee Department of Conservation, 701 Broadway, Nashville, TN 37203. Telephone No. (615) 742-6545.
The Michigan Natural Features Inventory has been monitoring one of the state's populations to obtain data on population trends and demographics (Penskar pers. comm.). Monitoring consists of tracking several tagged clumps of plants and has been conducted over the last five or six years. Contact: Mike Penskar, Michigan Natural Features Inventory, Mason building, 5th Floor, Box 30028, Lansing, MI 48909. Telephone No. (517) 373-1552.
The Alabama populations are being intermittently monitored by Dr. Murray Evans of the University of Tennessee. Contact: Dr. A. Murray Evans, Department of Botany, University of Tennessee, Knoxville, TN 37916. Telephone No. (615) 974-2256.
Management Research Programs: Dianne Cinquemani Kuehn and Don Leopold have recently completed a research program designed to determine the habitat variables to which Asplenium scolopendrium var. americanum (Phyllitis scolopendrium var. americana) is particularly sensitive. All extant sites in New York state have been visited and analyzed with respect to environmental parameters within the last few years. Contact: Donald Leopold, State University of New York, College of Environmental Science and Forestry, Syracuse, New York 13210. Telephone No. (315) 470-6784.
Phyllitis scolopendrium plants from the Tennessee site have been transplanted to the University of Tennessee herbarium with minor success. Contact: Gene Wofford, Curator, Herbarium, University of Tennessee, Knoxville, TN 37916. Telephone No. (615) 974- 6213.
Dr. Herb Wagner was working with two other individuals on the publication, "Pteridophytes of the Upper Great Lakes". It is expected to be completed within the next three years. Contact: Herbarium, University of Michigan, Ann Arbor, MI. Telephone No. (313) 764-1484.
Biological Research Needs: Population size and stage-class distribution for all populations need to be determined, and long-term demographic studies would be worthwhile (Currie 1993). Information pertaining to specific life-history events is needed. Ultimately, criteria for self-sustaining populations need to be defined (Currie 1993). Abiotic and biotic features of occupied habitat should also be studied, including effects of past and present habitat disturbance in order to assess the degree to which each has influenced populations. Information pertaining to effects of canopy thinning on germination, sporeling development, and growth and maintenance of adult plants is needed. Some botanists have maintained that Asplenium scolopendrium var. americanum is a taxon of secondary forests requiring partially sunlit, yet cool, moist environments, and it would be appropriate to measure the light levels reaching the forest floor at each site to determine whether very minimal canopy thinning would encourage population enhancement. Determination of the degree of genetic variability within populations and within the species is a strong need. Through isozyme analysis, the degree of genetic variability between population should be determined. Such information is necessary in order to determine which populations are essential for protection with respect to genetic variability maintenance (USFWS 1990). In addition, the size of the area needed to protect each population needs to be determined for recovery purposes (Currie 1993). Research also needs to be centered around the development of techniques to reestablish populations in suitable habitat within the species' historic range. Techniques for propagation and transplantation will be crucial to any future reintroduction program.