Myxomycetes of Cedars of Lebanon State Park, Wilson County, Tennessee

Castanea, Sep 2004 by Rosing, Wayne C

ABSTRACT

A survey of myxomycetes was conducted at three sites within Cedars of Lebanon State Park, Wilson County, Tennessee from May 1 to September 30, 1993. Fructifications that developed on samples of bark and plant debris placed in moist chamber cultures were used to supplement field collections. The present report deals with 216 specimens representing 54 species of myxomycetes. Two of these (Comatricha fimbriata and Hemitrichia intorta) are new reports from Tennessee.

INTRODUCTION

Braun (1950) referred to "cedar glades" as "open to dense stands of red cedar" (Juniperus virginiana L.) on flats of Lebanon limestone. She considered such "glades" the most distinctive feature of the Nashville Basin. Quarterman (1989) described a "glade complex or ecosystem" of "open gravelly/grassy true glades surrounded by or winding between shrub thickets and glade woods" that occur in "crevices or potholes of soil deep enough to support their growth."

Published information on the myxomycetes of Tennessee is scarce and, with the exception of one study (Leech and Rosing 2002), based exclusively on studies conducted in eastern Tennessee (Cooley 1934, Hagelstein 1940, Linder 1941, Weldon 1951, Farr 1979, Counts et al. 2000, Stephenson et al. 2001, Snell et al. 2003). This study reports on myxomycetes of the open glades, glade woods, and adjacent hardwood forests of middle Tennessee. All study sites are within Cedars of Lebanon State Park , Wilson County, Tennessee.

Site One

Approximately 230 m southeast of the park office, this site includes an open glade dominated by herbaceous plants as well as a narrow band of immediately adjacent glade woods that include Forestiera ligustrina (Michx.) Poir., Rhus aromatica Ait., Symphoricarpos orbiculatus Moench, Opuntia sp., J. virginiana, and Quercus muhlenbergii Englem. This is the most open and xeric of the sites and lies at an elevation of approximately 200 m.

Site Two

An area of mixed cedar-hardwood lies approximately 115 m east of the visitor's center, between Site One and the main drive. This site supports a number of large cedars as well as a number of smaller specimens of Ostrya virginiana (Miller) K. Koch., Juglans nigra L., Celtis laevigata Willd., Ulmus alata Michaux, Fraxinus quadrangulata Michx., Viburnum rufidulum Raf., Diospyros virginiana L., Carya carolinae-septentrionalis (Ashe) Engler & Graebner, as well as grape vines (Vitis spp.). This site is intermediate in its ability to hold moisture and only slightly higher in elevation than Site One at approximately 205 m.

Site Three

A hardwood forest occupies a ridge above the park naturalist's home. This site has an elevation of approximately 235 m and is characterized by deep soils and large trees: Quercus alba L., Q. muhlenbergii, Acer saccharum Marshall, J. nigra, D. virginiana, C. carolinae-septentrionalis, as well as by grape vines. An understory of Cercis canadensis L., O. virginiana, Morus rubra L., and Cornus florida L. is also present. Due to the deeper soil, this site has the greatest ability to retain moisture.

MATERIALS AND METHODS

A 30 by 30 m plot was established at each collection site and its corners inconspicuously marked. Two hours were spent sampling each plot during each week of the collection period, May 1-September 30, 1993. Fruiting bodies were collected from leaf litter, fallen logs, twigs, living plants, and soil. Keys by Martin and Alexopoulos (1969) were used to make species identifications. Periodically, bark and litter samples from each site were collected, moist chambered in the manner described by Gilbert and Martin (1933), and examined closely for plasmodia and fruiting bodies for a three week period. Mitchell's (1980) key to corticolous myxomycetes was utilized for identifications. Nomenclature and species descriptions essentially follow Martin and Alexopoulos (1969).

RESULTS AND DISCUSSION

Microscopic examination of 216 specimens revealed 54 species of myxomycetes (Table 1). Two of these species (Comatricha fimbriata and Hemitrichia intorta) have not been reported previously in the literature as occurring in Tennessee. In addition, only one previous report of Physarum lateritium has ever been made (Linder 1941). Voucher specimens have been deposited in the MTSU herbarium.

Data from the National Weather Service indicate that average temperatures for June, July and August of 1993 were higher than normal at the Nashville International Airport, some thirty two kilometers west of the park. However, rainfall was below normal for all months of the study period except June. Undoubtedly, a survey of the same three study sites would reveal additional species of myxomycetes during a cooler, wetter growing season.

ACKNOWLEDGMENTS

The author wishes to thank Drs. S.L. Stephenson and H.W. Keller for their assistance with the identification of specimens, the Faculty Research Committee at Middle Tennessee State University for supporting the investigation, and Mr. Sandy Suddarth, Park Naturalist, for his assistance marking the collecting sites.