Mac CallahamProject Leader (Acting)/Research Ecologist
Athens, GA 30602-2044
I am interested in soil ecosystem responses to natural disturbances (fire, wind, and flood), forest management practices which seek to simulate disturbances (prescribed fire, thinning, harvesting), and anthropogenic disturbances (e.g. invasive species). I am particularly interested in responses of soil biota (e.g. earthworms, herbivorous insects, soil microbes, etc.) to these disturbances and land management practices, and how changes in invertebrate assemblages may lead to changes in other components of forest systems (e.g. nutrient relationships, plant-herbivore relationships). In addition to pure soil biology, I am also interested in elemental dynamics, and specifically the effects of prescribed fire on soil organic matter and toxics (soil carbon, nitrogen, and mercury).
- Ph.D. in Biology, 2000
- Kansas State University
- M.S. in Agronomy, 1996
- University of Georgia
- B.A. in English, 1994
- University of Georgia
- B.S. in Zoology, 1994
- University of Georgia
Featured Publications and Products
- Lilleskov, Erik; Callaham, Jr. Mac A.; Pouyat, Richard; Smith, Jane E.; Castellano, Michael; Gonzalez, Grizelle; Lodge, D. Jean; Arango, Rachel; Green, Frederick. 2010. Invasive soil organisms and their effects on belowground processes.
- Callaham, M.A., Jr. 2009. Grunting for worms: reactions of Diplocardia to seismic vibrations.
- O’Brien, J.J.; Hiers, J.K.; Callaham, M.A., Jr..; Mitchell, R.J.; Jack, S. 2008. Interactions among overstory structure, seedling life-history traits and fire in frequently burned neotropical pine forests.
- Kitchen, D.J.; Blair, J.M.; Callaham, M.A. , Jr. 2009. Annual fire and mowing alter biomass, depth distribution, and C and N content of roots in soil in tallgrass prairie.
- Callaham, M.A. 2008. Pandora’s box contained bait: The global problem of introduced earthworms.
- Whiles, Matt R.; Snyder, Bruce A.; Brock, Brent L.; Bonjour, Sophia ; Callaham, Mac A.; Meyer, Clinton K.; Bell, Alex . 2019. Periodical cicada emergence resource pulse tracks forest expansion in a tallgrass prairie landscape.
- Flanagan, Steven A.; Bhotika, Smriti; Hawley, Christie; Starr, Gregory; Wiesner, Susanne; Hiers, J. Kevin; O'Brien, Joseph; Goodrick, Scott; Callaham Jr., Mac A.; Scheller, Robert M.; Klepzig, Kier D.; Taylor, R. Scott; Loudermilk, E. Louise. 2019. Quantifying carbon and species dynamics under different fire regimes in a southeastern U.S. pineland.
- Snyder, Bruce A.; Callaham, Mac A. 2019. Soil fauna and their potential responses to warmer soils.
- Blackmon IV, James H.; Taylor, Melanie K.; Carrera-Martinez, Roberto ; Snyder, Bruce A.; Callaham Jr., Mac A. 2019. Temperature affects hatching success of cocoons in the invasive Asian earthwork Amynthas agrestis from the southern Appalachians.
- Carrera-Martínez, Roberto; Callaham, Mac A. Jr. 2018. Observations on an epilobic Lumbricus rubellus (Oligochaeta, Lumbricidae) from the Great Smoky Mountains National Park, Tennessee, USA.
- CHANG, Liang; WANG, Baifeng; LIU, Xianghui; CALLAHAM, Mac A.; GE, Feng. 2017. Recovery of Collembola in Pinus tabulaeformis plantations.
- Strickland, Michael S.; Callaham, Mac A.; Gardiner, Emile S.; Stanturf, John A.; Leff, Jonathan W.; Fierer, Noah; Bradford, Mark A. 2017. Response of soil microbial community composition and function to a bottomland forest restoration intensity gradient.
- Coyle, David R.; Nagendra, Uma J.; Taylor, Melanie K.; Campbell, J. Holly; Cunard, Chelsea E.; Joslin, Aaron H.; Mundepi, Abha; Phillips, Carly A.; Callaham, Mac A. 2017. Soil fauna responses to natural disturbances, invasive species, and global climate change: Current state of the science and a call to action.
- Gao, Meixiang; Taylor, Melanie K.; Callaham, Mac A. 2017. Trophic dynamics in a simple experimental ecosystem: Interactions among centipedes, Collembola and introduced earthworms.
- Butt, Kevin R.; Callaham, Mac; Loudermilk, E. Louise; Blaik, Rowan. 2016. Action of earthworms on flint burial - a return to Darwin's estate.
- Butt, K.R.; Lowe, C.N.; Callaham, Mac; Nuutinen, V. 2016. An oasis of fertility on a barren island: earthworms at Papadil, Isle of Rum.
- Callaham, Mac A.; Snyder, Bruce A.; James, Samuel W.; Oberg, Erik T. 2016. Evidence for ongoing introduction of non-native earthworms in the Washington, DC metropolitan area.
- Callaham, Mac A. 2016. Introduction.
- Wenk, Evelyn S.; Callaham, Mac A.; O'Brien, Joseph; Hanson, Paul J. 2016. Soil macroinvertebrate communities across a productivity gradient in deciduous forests of eastern North America.
- Ikeda, Hiroshi; Callaham Jr., Mac A.; O'Brien, Joseph J.; Hornsby, Benjamin S.; Wenk, Evelyn S. 2015. Can the invasive earthworm, Amynthas agrestis, be controlled with prescribed fire?.
- Richter, Daniel deB; Bacon, Allan R.; Billings, Sharon A.; Binkley, Dan; Buford, Marilyn; Callaham, Mac; Curry, Amy E.; Fimmen, Ryan L.; Grandy, A. Stuart; Heine, Paul R.; Hofmockel, Michael; Jackson, Jason A.; LeMaster, Elisabeth; Li, Jianwei; Markewitz, Daniel; Mobley, Megan L.; Morrison, Mary W.; Strickland, Michael S.; Waldrop, Thomas; Wells, Carol G. 2015. Evolution of soil, ecosystem, and critical zone research at the USDA FS Calhoun Experimental Forest.
- Oliver, Alena K.; Brown, Shawn P.; Callaham, Mac A.; Jumpponen, Ari. 2015. Polymerase matters: non-proofreading enzymes inflate fungal community richness estimates by up to 15 %.
- Oliver, Alena K.; Callaham, Mac A.; Jumpponen, Ari. 2015. Soil fungal communities respond compositionally to recurring frequent prescribed burning in a managed southeastern US forest ecosystem.
- Zhang, Bing; Chang, Liang; Ni, Zhen; Callaham, Mac A.; Sun, Xin; Wu, Donghui. 2014. Effects of land use changes on winter-active Collembola in Sanjiang Plain of China.
- McFarlane, Karis J.; Torn, Margaret S.; Hanson, Paul J.; Porras, Rachel C.; Swanston, Christopher W.; Callaham, Mac A.; Guilderson, Thomas P. 2013. Comparison of soil organic matter dynamics at five temperate deciduous forests with physical fractionation and radiocarbon measurements.
- Snyder, Bruce; Callaham, Mac, Jr..; Lowe, Christopher; Hendrix, Paul. 2013. Earthworm invasion in North America: Food resource competition affects native millipede survival and invasive earthworm reproduction.
- Gambrell, Horace E.; Waldrop, Thomas A.; Wang, G. Geoff; Callaham, Mac A.; Bridges, William C. 2013. Fuel dynamics across southern Appalachian landscapes.
- Stottlemyer, Aaron D.; Wang, G. Geoff; Waldrop, Thomas A.; Wells, Christina E.; Callaham, Mac A. 2013. Short-term effects of fuel reduction treatments on soil mycorrhizal inoculum potential in beetle-killed stands.
- Callaham, Mac A., Jr..; Stanturf, John A.; Hammond, William J.; Rockwood, Donald L.; Wenk, Evelyn S.; O’Brien, Joseph J. 2013. Survey to evaluate escape of Eucalyptus spp. seedlings from plantations in southeastern USA.
- Callaham, Mac A., Jr..; Scott, D. Andrew; O’Brien, Joseph J.; Stanturf, John A. 2012. Cumulative effects of fuel management on the soils of eastern U.S.
- van Vliet, P.C.J.; Hendrix, P.F.; Callaham, M.A., Jr. 2012. Soil Fauna: Earthworms.
- Callaham, M.A., Jr..; Crossley, D.A., Jr..; Coleman, D.C. 2012. Soil Fauna: Macroarthropods.
- Callaham, Mac A., Jr..; Rhoades, Charles C.; Heneghan, Liam. 2008. A striking profile: Soil ecological knowledge in restoration management and science.
- Heneghan, Liam; Miller, Susan P.; Baer, Sara; Callaham, Mac A., Jr..; Montgomery, James; Pavao-Zuckerman, Mitchell; Rhoades, Charles C.; Richardson, Sarah. 2008. Integrating soil ecological knowledge into restoration management.
- Callaham, M.A. 2008. Integrating soil ecological knowledge into restoration management.
- Callaham, M.A., Jr. 2008. Special Section: Soil Ecology and Restoration Ecology.
- DiCosty, Ralph J.; Callaham, Mac A.; Stanturf, John A. 2006. Atmospheric deposition and re-emission of mercury estimated in a prescribed forest-fire experiment in Florida, USA.
- O'Brien, Joseph; Stahala, Caroline; Mori, Gina P.; Callaham, Mac; Bergh, Chris M. 2006. Effects of prescribed fire on conditions inside a Cuban parrot (Amazona Leucocephala) surrogate nesting cavity on Great Abaco, Bahamas.
- Callaham, Mac A., Jr..; Gonzalez, Grizelle; Hale, Cynthia M; Henegham, Liam; Lachnicht, Sharon L.; Zou, Xiaoming. 2006. Policy and management responses to earthworm invasions in North America.
- Phillips, Ross J.; Waldrop, Thomas A.; Chapman, Gregg L.; Mohr, Helen H.; Callaham, Mac A.; Flint, Charles T., Jr. 2004. Effects of Fuel-Reduction Techniques on Vegetative Composition of Piedmont Loblolly-Shortleaf Pine Communities: Preliminary Results of the National Fire and Fire Surrogate Study.
- Callaham, Mac A., Jr..; Anderson, Peter H.; Waldrop, Thomas A.; Lione, Darren J.; Shelburne, Victor B. 2004. Litter Decomposition and Soil Respiration Responses to Fuel-Reduction Treatments in Piedmond Loblolly Pine Forests.
- Callaham, Mac A., Jr..; Whiles, Matt R.; Blair, John M. 2002. Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie.
- Callaham, Mac A., Jr..; Stewart, Arthur J.; Alarcon, Clara; McMillen, Sara J. 2002. Effects of Earthworm (Eisenia fetida) and Wheat (Triticum aestivum) Straw Additions on Selected Properties of Petroleum-Contaminated Soils.
- Callaham, Mac A., Jr..; Blair, John M. 2001. Different behavioral patterns of the earthworms Octolasion tyrtaeum and Diplocardia spp. in tallgrass prairie soils: potential influences on plant growth.
- Earthworms, Millipedes, and Soil Carbon in the Eastern U.S. (2016)
- Earthworms, millipedes, and other soil invertebrates directly contribute to forest soil processes such as leaf litter decomposition and soil organic matter formation. There is relatively little known about how the composition of soil macroinvertebrate communities varies across temperature and moisture gradients in eastern deciduous forests. Forest Service scientists found that non-native earthworms were associated with declines in other important groups of detritivores (invertebrates that eat decaying plant matter), such as millipedes, as well as with much faster decomposition rates of leaf litter in the forest floor.
- Invasive earthworms have unexpected effects on other soil organisms (2017)
- Invasive earthworms alter the structure and function of soil. Forest Service scientists show that these earthworms decrease the abundance of springtails, but act as a food source for centipedes. These changes are likely to alter the communities of other soil-dwelling organisms, with potential rippling effects on the forest soil food web.
- Prescribed Fire to Stem the Tide of Earthworm Invasion (2015)
- Asian earthworms are currently invading eastern deciduous forests from Georgia to Vermont. Because these earthworms eat leaf litter in the forest floor, Forest Service scientists and collaborators hypothesized that applying some heat and removing some of this food source with prescribed fire might slow or repel these invaders. In a controlled experiment, the scientists found that fire resulted in much lower reproductive success for the invasive earthworms. This may have application in controlling invasions in the field.
- Short-circuiting an Invasional Meltdown (2014)
- Chinese privet is an invasive plant species in flood plain forests of the southeastern U.S., in some cases occupying up to 80 percent of available riparian floodplain forest habitat. Non-native invasive earthworm species are found in the same soils where Chinese privet is abundant. In this study, Forest Service scientists showed that five years after removal of the plant, there were lower numbers of certain invasive earthworm species, and a simultaneous recovery in numbers of native species.
- Soil fauna are of vital importance to soil processes and deserve attention (2017)
- Although soil fauna are critically important for many ecosystem services, they are often neglected by researchers. Scientists at the Forest Service and the University of Georgia discuss reasons for this in their review of how disturbance affects these organisms.