REPORT ON THE ACTIVITIES OF THE ATBI SLIME MOLD TWIG
December 1999

MYXOMYCETES

Members of the slime mold TWIG made three myxomycete collecting trips to the Great Smoky Mountains National Park during the latter half of 1999. One trip was in mid-July, another took place in early August, and the third occurred during the latter part of September. In addition to field collections of myxomycetes, samples of bark, litter, and other types of organic debris were collected on each trip, returned to the laboratory, and used to prepare moist chamber cultures for the isolation of myxomycetes. Prior to the beginning of the ATBI, 87 species of myxomycetes had been reported from the Park. As a result of the three collecting trips carried out during the latter half of 1999 and two earlier trips (one in April of 1999 and the other in September of 1998), more than 40 species have been added to this total. Two of the species collected (Lamproderma granulosum and Licea sambucina) were not previously known from the New World, and a third species (Elaeomyxa miyazakiensis, which was pictured in the recent Newsweek article) was not previously known from the eastern United States. At least two other species that have been collected may be new to science. All of the new records of myxomycetes from the Park are listed below.

DICTYOSTELIDS

A trip to the Great Smoky Mountains National Park for the purpose of collecting dictyostelid cellular slime molds was carried out during the latter part of October. Ten samples of soil and litter material were collected from each of six different sites adjacent to ATBI study plots. These study plots were those located at Ramsey Cascades, Snakeden Ridge, Tremont, Clingmans Dome, Indian Gap, and Oconaluftee (on the flood plain). The sixty samples were returned to the laboratory and processed for dictyostelids by the Cavender method. In addition to recording the appearance of dictyostelids, the pH of each sample was determined.

Fourteen identified species of dictyostelids were recovered, including two species (Dictyostelium septentrionalis and Polysphondylium candidum) not previously known from the Park along with all twelve of the species previously reported from the Park. In addition, three to four other forms were isolated that are likely to be new records for the Park; one of these is possibly a species new to science. These forms are currently in subculture and will be subjected to further study. In general, as in other similar surveys, species richness (which ranged from two to eight) and densities (which ranged from 10 to 138 clones/gram) of dictyostelids were greater at lower elevations and in soils with higher pH values.

In addition to the sampling effort described above, four species of dictyostelids (Dictyostelium aureo-stipes, Dictyostelium discoideum, Dictyostelium purpureum and Polysphondylium pallidum) were recovered from a sample of soil collected (by Will Reeves) from Rainbow Cave.

All of the species of dictyostelids now known from the Park are listed below.

PROTOSTELIDS

One aspect of the sampling effort carried out during the visit made to the Great Smoky Mountains National Park in late September of 1999 involved collecting samples of forest floor litter and aerial litter (dead but still attached plant parts) for isolation of protostelids. Samples were collected from thirteen different study sites throughout the Park. Not all of these samples have been processed, but those samples that have been examined have yielded eleven different species of protostelids. We are not aware of any previous records of protostelids from the Park. Species recorded to date are listed below.

In summary, at least 155 species of slime molds (myxomycetes, dictyostelids, and protostelids) are now known from the Great Smoky Mountains National Park. Fifty-six of these (representing 36% of the total) have been added to the mycoflora of the Park as a result of the sampling effort carried out during the first year of the ATBI.
Members of the slime mold TWIG:

Steve Stephenson (coordinator)
Martin Schnittler
John Landolt
David Mitchell
Yura Novozhilov
Andy Swanson
Donna Moore
Denise Binion
Randy Darrah
Roland McHugh
Fred Spiegel
Adam Rollins (student)
Krystal Kolozy (student)
Heather Robertson (student)
Maribeth Overking (student)
Amanda Kerns (student)
Dawn Black (student)