RELATIONSHIPS BETWEEN DEAD WOOD AND ARTHROPODS IN THE SOUTHEASTERN UNITED STATES by MICHAEL DARRAGH ULYSHEN (Under the Direction of James L. Hanula) ABSTRACT The importance of dead wood to maintaining forest diversity is now widely recognized. However, the habitat associations and sensitivities of many species associated with dead wood remain unknown, making it difficult to develop conservation plans for managed forests. The purpose of this research, conducted on the upper coastal plain of South Carolina, was to better understand the relationships between dead wood and arthropods in the southeastern United States. In a comparison of forest types, more beetle species emerged from logs collected in upland pine-dominated stands than in bottomland hardwood forests. This difference was most pronounced for Quercus nigra L., a species of tree uncommon in upland forests. In a comparison of wood postures, more beetle species emerged from logs than from snags, but a number of species appear to be dependent on snags including several canopy specialists. In a study of saproxylic beetle succession, species richness peaked within the first year of death and declined steadily thereafter. However, a number of species appear to be dependent on highly decayed logs, underscoring the importance of protecting wood at all stages of decay. In a study comparing litter-dwelling arthropod abundance at different distances from dead wood, arthropods were more abundant near dead wood than away from it. In another study, ground- dwelling arthropods and saproxylic beetles were little affected by large-scale manipulations of dead wood in upland pine-dominated forests, possibly due to the suitability of the forests surrounding the plots. INDEX WORDS: dead wood, coarse woody debris, saproxylic, Coleoptera, litter-dwelling arthropods, ground-dwelling arthropods, snags, logs RELATIONSHIPS BETWEEN DEAD WOOD AND ARTHROPODS IN THE SOUTHEASTERN UNITED STATES by MICHAEL DARRAGH ULYSHEN B.S., Miami University, 2002 M.S., University of Georgia, 2005 A Dissertation Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY ATHENS, GEORGIA 2009 © 2009 Michael Darragh Ulyshen All Rights Reserved RELATIONSHIPS BETWEEN DEAD WOOD AND ARTHROPODS IN THE SOUTHEASTERN UNITED STATES by MICHAEL DARRAGH ULYSHEN Major Professor: James L. Hanula Committee: Joseph McHugh Darold Batzer Electronic Version Approved: Maureen Grasso Dean of the Graduate School The University of Georgia May 2009 ACKNOWLEDGEMENTS I thank my advisor Jim Hanula and committee members Joe McHugh and Darold Batzer for overseeing this research. The following people were of invaluable assistance in the field or lab: Scott Horn, Danny Dyer, Mike Cody, Stephanie Cahill, Margo Briesch, Walter Sikora, Ryan Malloy, Jared Swain and Mary Williams. I also wish to thank Harry Lee, Bob Rabaglia, Alexey Tishechkin, and Chris Carlton for assistance in identifying Carabidae, Scolytinae, Histeridae, and Pselaphinae, respectively. I am grateful to Cecil Smith and Mike Thomas for their assistance and hospitality during visits to the Georgia Museum of Natural History and the Florida State Collection of Arthropods, respectively. Finally, I thank and am in particular debt to the Ulyshens and Keisters. Support for this research was provided by the Department of Energy-Savannah River Operations Office through the U.S. Forest Service Savannah River under Interagency Agreement DE-AI09-00SR22188. iv TABLE OF CONTENTS Page ACKNOWLEDGEMENTS............................................................................................................iv CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW.....................................................1 2 HABITAT ASSOCIATIONS OF SAPROXYLIC BEETLES IN THE SOUTHEASTERN UNITED STATES: A COMPARISON OF FOREST TYPES, TREE SPECIES AND WOOD POSTURES............................................................3 3 RESPONSES OF ARTHROPODS TO LARGE SCALE MANIPULATIONS OF DEAD WOOD IN LOBLOLLY PINE STANDS OF THE SOUTHEASTERN UNITED STATES..................................................................................................47 4 PATTERNS OF SAPROXYLIC BEETLE SUCCESSION IN LOBLOLLY PINE..83 5 CONCLUSIONS........................................................................................................117 v CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW Dead wood is an important resource and structural element in terrestrial, aquatic, estuarine, coastal beach, and open ocean habitats throughout the world (Maser et al. 1988). In terrestrial systems dead wood plays an important role in nutrient cycling and provides habitat for many plants, animals, fungi, and bacteria (Harmon et al. 1986). Terrestrial animal communities found within dead wood are dominated by arthropods, with beetles being the most diverse of all. It has been estimated that about 20-25% of all beetle species are saproxylic, meaning they cannot persist without dead or dying wood (Elton 1966, Grove 2002). Because timber harvesting operations inevitably reduce the volume and diversity of dead wood, saproxylic beetles have been severely impacted by forest management in many parts of the world. In Finland, for example, the amount of dead wood across the landscape has been reduced by 90-98%, putting over half of all saproxylic species at risk of disappearance (Siitonen 2001). Unfortunately, biodiversity research in North America is in its infancy and the status of most arthropods remains completely unknown. However, we do have some idea how many beetle species are present and potentially at risk at both continental and regional scales. North America north of Mexico contains approximately 25,160 beetle species (Marske and Ivie 2003) and the relatively small state of South Carolina, where this research took place, contains at least 3,346 species (Peck and Thomas 1998, and references therein). Assuming that 20-25% of all beetle species depend on dead wood (Elton 1966, Grove 2002), it can be estimated that South Carolina alone contains between 669 and 836 saproxylic beetle species! Research is urgently needed to better understand 1 the status and requirements of this diverse community if the biological catastrophe experienced in the boreal forests of northern Europe is to be avoided in the southeastern United States. Literature Cited Elton, C. S. 1966. The Pattern of Animal Communities. Methuen and Co Ltd, London. 432 p. Grove, S. J. 2002. Saproxylic insect ecology and the sustainable management of forests. Annual Review of Ecology and Systematics. 33: 1-23. Harmon, M. E., Franklin, J. F., Swanson, F. J., Sollins, P., Gregory, S. V., Lattin, J. D., Anderson, N. H., Cline, S. P., Aumen, N. G., Sedell, J. R., Lienkaemper, G. W., Cromack, K., Jr., Cummins, K. W. 1986. Ecology of coarse woody debris in temperate ecosystems. Advances in Ecological Research 15: 133-302. Marske, K. A., Ivie, M. A. 2003. Beetle fauna of the United States and Canada. The Coleopterists Bulletin 57: 495-503. Maser, C., Tarrant, R. F., Trappe, J. M., Franklin, J. F. (tech. eds.). 1988. From the forest to the sea: a story of fallen trees. USDA Forest Service General Technical Report PNW-GTR- 229. 153 p. Peck, S. B., Thomas, M. C. 1998. A distributional checklist of the beetles (Coleoptera) of Florida. Arthropods of Florida and neighboring land areas. Vol. 16. 180 pp. Siitonen, J. 2001. Forest management, coarse woody debris and saproxylic organisms: Fennoscandian boreal forests as an example. Ecological Bulletins 49: 11-41. 2 CHAPTER 2 HABITAT ASSOCIATIONS OF SAPROXYLIC BEETLES IN THE SOUTHEASTERN UNITED STATES: A COMPARISON OF FOREST TYPES, TREE SPECIES AND WOOD POSTURES¹ ¹Ulyshen, M.D. and J.L. Hanula. 2009. Forest Ecology and Management 257: 653-664. Reprinted here with permission of publisher. 3 Abstract Saproxylic beetles are highly sensitive to forest management practices that reduce the abundance and variety of dead wood. Yet this diverse fauna continues to receive little attention in the southeastern United States even though this region supports some of the most diverse, productive and intensively managed forests in North America. In this replicated three-way factorial experiment, we investigated the habitat associations of saproxylic beetles on the coastal plain of South Carolina. The factors of interest were forest type (upland pine-dominated vs. bottomland hardwood), tree species (Quercus nigra L., Pinus taeda L. and Liquidambar styraciflua L.) and wood posture (standing and downed dead wood, i.e., snags and logs). Wood samples were taken at four positions along each log and snag (lower bole, middle bole, upper bole and crown) ~11 months after the trees were killed and placed in rearing bags to collect emerging beetles. Overall, 33,457 specimens from 51 families and ≥ 250 species emerged. Based on an analysis of covariance, with surface area and bark coverage as covariates, saproxylic beetle species richness differed significantly for forest type and wood posture. There were no significant interactions. Species richness was significantly higher in the upland pine-dominated stand than the bottomland hardwood forest, possibly due to higher light exposure in upland forests. Although L. styraciflua yielded more beetle species (152) than either Q. nigra (122) or P. taeda (125), there were no significant differences in species richness among tree species. There were also no relationships evident between relative tree abundance and observed or expected beetle species richness. Significantly