Masters Theses

Date of Award

8-1999

Degree Type

Thesis

Degree Name

Master of Science

Major

Entomology and Plant Pathology

Major Professor

Paris L. Lambdin

Committee Members

David Etnier, Jerome Grant

Abstract

Sinking Pond, located in Coffee County, TN, at the coordinates 35deg;24'37"N, 86°4'10"W, comprises 52 ha, while the basin and watershed surrounding the pond are more than 155 ha (including the pond). The water level in the pond can rise and fall 2 m within 24 hours, and water depths vary from 0 to 3.5 m. Sinking Pond is a unique habitat which is representative of karst topography, a landscape type associated with most major cave systems. Sinking Pond is located in an area of middle TN called the Barrens, which contains many animal and plant species disjunct, or separated, from their established distributions.

The Sinking Pond watershed has at least seven tree community types. The primary reason for Sinking Pond's uniqueness is a community of overcup oak (Quercus lyrata Walter), river birch (Betula nigra L.), and resurrection fern (Pleopeltis polypodioides Andrews and Windham), which is found in the deepest and most regularly flooded areas. This old-growth forest habitat type occurs nowhere else in Tennessee, or the world, and has been tentatively labeled G1 by the Tennessee Chapter of the Nature Conservancy. A G1 ranking indicates that less than five occurrences of this habitat occur globally and that it is "critically imperiled".

Currently no studies have been conducted to assess the arthropod community of this unique site. As a result, a research project was initiated in 1997 at Sinking Pond to sample and document the terrestrial arthropod community, and to compile a list of species associated with Sinking Pond. This information was developed into a database to be used in future studies of the site. The invertebrate information was used to evaluate diversity, assess ecological significance of select species, and identify potential indicator species. The nine sampling techniques used were: beat sheeting, canopy fogging, direct collecting, leaf-litter sampling, light trapping, malaise trapping, Manitoba trapping, pitfall trapping, and sweep netting.

A total of 23,929 arthropod specimens, representing 28 orders, was collected. Of these, 12,816 (53.6%) were adult insects in 20 orders and 11,113 (46.4%) were noninsects in 8 orders. From these insect and non-insect orders, 826 different species were identified in 200 families. Specimens from eight insect orders (Coleoptera, Collembola, Hymenoptera, Diptera, Homoptera, Hemiptera, Lepidoptera, and Orthoptera) made up 98.3% of the insect specimens. The five orders with the highest number of species were Coleoptera, Diptera, Lepidoptera, Homoptera, and Collembola, respectively. The Shannon diversity index (H') was calculated as 4.69, a high diversity score, and evenness was 0.69, which represents an average value

. Four species, Cicindela unipunctata F., Enodia anthedon Clark, Glaucopsyche lygdamus (Doubleday), and Speyeria cybele (F.), from Sinking Pond were on the rare, threatened, or endangered species lists of Alabama or North Carolina. These species do not appear to be rare in TN.

From the species identified, 12 may represent disjunct species. Their presence may suggest that the unique habitat of Sinking Pond have attributes that enable the survival of these unusual genotypes.

Eight introduced species were identified in the collections from Sinking Pond. These included five beetle species, Cyrtepistomis castaneous (Roelofs) (Curculionidae), Demotina modestus Baly (Chrysomelidae), Coccinella septempunctata L. (Coccinellidae), Harmonia axyridis (Pallas) (Coccinellidae), and Popillia japonica Newman (Scarabaeidae), and three hymenopterans, Apis mellifera L. (Apidae), and Tertramorium caespitum (L.) and Wasmannia auropunctata (Roger), both in family Formicidae. Some of these species could potentially have an adverse effect on the community of Sinking Pond.

A diverse arthropod fauna was identified associated with Sinking Pond. The database of arthropod information developed during this study may be helpful in evaluating the effects of changes in the community, such as from exotic species. Baseline data are needed to evaluate any future changes or impacts on this community. Additionally, information on species that may be useful as indicators of ecosystem health would be instrumental in the management of this unique habitat.

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