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Ants accelerate litter decomposition in a Costa Rican lowland tropical rain forest

Published online by Cambridge University Press:  29 August 2012

Terrence P. McGlynn*
Department of Biology, California State University Dominguez Hills, 1000 E. Victoria St., Carson, CA 90747USA
Evan K. Poirson
Evan K. Poirson, Department of Biology, Occidental College, Los Angeles, CA, USA
1Corresponding author. Email:


The decomposition of leaf litter is governed, in part, by litter invertebrates. In tropical rain forests, ants are dominant predators in the leaf litter and may alter litter decomposition through the action of a top-down control of food web structure. The role of ants in litter decomposition was investigated in a Costa Rican lowland rain forest with two experiments. In a mesocosm experiment, we manipulated ant presence in 50 ambient leaf-litter mesocosms. In a litterbag gradient experiment, Cecropia obtusifolia litter was used to measure decomposition rate constants across gradients in nutrients, ant density and richness, with 27 separate litterbag treatments for total arthropod exclusion or partial arthropod exclusion. After 2 mo, mass loss in mesocosms containing ants was 30.9%, significantly greater than the 23.5% mass loss in mesocosms without ants. In the litter bags with all arthropods excluded, decomposition was best accounted by the carbon: phosphorus content of soil (r2 = 0.41). In litter bags permitting smaller arthropods but excluding ants, decomposition was best explained by the local biomass of ants in the vicinity of the litter bags (r2 = 0.50). Once the microarthropod prey of ants are permitted to enter litterbags, the biomass of ants near the litterbags overtakes soil chemistry as the regulator of decomposition. In concert, these results support a working hypothesis that litter-dwelling ants are responsible for accelerating litter decomposition in lowland tropical rain forests.

Research Article
Copyright © Cambridge University Press 2012

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BESTELMEYER, B. T., AGOSTI, D., ALONSO, L. E., BRANDÃO, C. R. F., BROWN, W. L., DELABIE, J. H. C. & SILVESTRE, R. 2000. Field techniques for the study of ground-dwelling ants: an overview, description and evaluation. Pp. 122144 in Agosti, D., Majer, J., Alonso, L. E. & Schultz, T. D. (eds.). Ants: Standard methods for measuring and monitoring biodiversity. Smithsonian Institution Press, Washington, DC.Google Scholar
BRADFORD, M. A., TORDOFF, G. M., EGGERS, T., JONES, T. H. & NEWINGTON, J. E. 2002. Microbiota, fauna, and mesh size interactions in litter decomposition. Oikos 99:317323.CrossRefGoogle Scholar
BYRNE, M. M. 1994. Ecology of twig-dwelling ants in a wet lowland tropical forest. Biotropica 26:6172.CrossRefGoogle Scholar
CLEVELAND, C. C., TOWNSEND, A. R. & SCHMIDT, S. K. 2002. Phosphorus limitation of microbial processes in moist tropical forests: evidence from short-term laboratory incubations and field studies. Ecosystems 5:680691.CrossRefGoogle Scholar
CLEVELAND, C. C., REED, S. C. & TOWNSEND, A. R. 2006. Nutrient regulation of organic matter decomposition in a tropical rain forest. Ecology 87:492503.CrossRefGoogle Scholar
COQ, S., SOUQUET, J.-M., MEUDEC, E., CHEYNIER, V. & HÄTTENSCHWILER, S. 2010. Interspecific variation in leaf litter tannins drives decomposition in a tropical rain forest of French Guiana. Ecology 91:20802091.CrossRefGoogle Scholar
CUSACK, D. F., CHOU, W. W., YANG, W. H., HARMON, M. E. & SILVER, W. L. 2009. Controls on long-term root and leaf litter decomposition in neotropical forests. Global Change Biology 15:13391355.CrossRefGoogle Scholar
ESPELETA, J. & CLARK, D. 2007. Multi-scale variation in fine-root biomass in a tropical rain forest: a seven-year study. Ecological Monographs 77:377404.CrossRefGoogle Scholar
GONZÁLEZ, G. & SEASTEDT, T. R. 2001. Soil fauna and plant litter decomposition in tropical and subalpine forests. Ecology 82:955964.CrossRefGoogle Scholar
HÄTTENSCHWILER, S. & GASSER, P. 2005. Soil animals alter plant litter diversity effects on decomposition. Proceedings of the National Academy of Sciences USA 102:15191524.CrossRefGoogle ScholarPubMed
HÄTTENSCHWILER, S., TIUNOV, A. V. & SCHEU, S. 2005. Biodiversity and litter decomposition in terrestrial ecosystems. Annual Review of Ecology, Evolution and Systematics 36:191218.CrossRefGoogle Scholar
HENEGHAN, L., COLEMAN, D. C., ZOU, X., CROSSLEY, D. A. & HAINES, B. L. 1998. Soil microarthropod community structure and litter decomposition dynamics: a study of tropical and temperate sites. Applied Soil Ecology 9:3338.CrossRefGoogle Scholar
HUNTER, M. D., ADL, S., PRINGLE, C. M. & COLEMAN, D. C. 2003. Relative effects of macroinvertebrates and habitat on the chemistry of litter during decomposition. Pedobiologia 47:101115.CrossRefGoogle Scholar
JACQUEMIN, J., MARAUN, M., ROISIN, Y. & LEPONCE, M. 2012. Differential response of ants to nutrient addition in a tropical brown food web. Soil Biology and Biochemistry 46:1017.CrossRefGoogle Scholar
JOHNSON, J. & OMLAND, K. 2004. Model selection in ecology and evolution. Trends in Ecology and Evolution 19:101108.CrossRefGoogle ScholarPubMed
KASPARI, M. 1996a. Worker size and seed size selection by harvester ants in a Neotropical forest. Oecologia 105:397404.CrossRefGoogle Scholar
KASPARI, M. 1996b. Litter ant patchiness at the 1-m2 scale: disturbance dynamics in three Neotropical forests. Oecologia 107:265273.CrossRefGoogle ScholarPubMed
KASPARI, M. & YANOVIAK, S. 2008. Biogeography of litter depth in tropical forests: evaluating the phosphorus growth rate hypothesis. Functional Ecology 22:919923.CrossRefGoogle Scholar
KASPARI, M. & YANOVIAK, S. P. 2009. Biogeochemistry and the structure of tropical brown food webs. Ecology 90:33423351.CrossRefGoogle ScholarPubMed
KASPARI, M., GARCIA, M., HARMS, K., SANTANA, M., WRIGHT, S. & YAVITT, J. 2008. Multiple nutrients limit litterfall and decomposition in a tropical forest. Ecology Letters 11:3543.Google Scholar
LACH, L., PARR, C. & ABBOTT, K. 2010. Ant ecology. Oxford University Press, Oxford. 432 pp.Google Scholar
MCDADE, L., BAWA, K. S., HESPENHEIDE, H. A. & HARTSHORN, G. S. 1994. La Selva: ecology and natural history of a Neotropical rain forest. University of Chicago Press, Chicago. 493 pp.Google Scholar
MCGLYNN, T. P. 2006. Ants on the move: resource limitation of a litter-nesting ant community in Costa Rica. Biotropica 38:419427.CrossRefGoogle Scholar
MCGLYNN, T. 2010. Polygyny in thief ants responds to competition and nest limitation but not food resources. Insectes Sociaux 57:2328.CrossRefGoogle Scholar
MCGLYNN, T. P. & OWEN, J. P. 2002. Food supplementation alters caste allocation in a natural population of Pheidole flavens, a dimorphic leaf-litter dwelling ant. Insectes Sociaux 49:814.CrossRefGoogle Scholar
MCGLYNN, T. P., FAWCETT, R. M. & CLARK, D. A. 2009a. Litter biomass and nutrient determinants of ant density, nest size and growth in a Costa Rican tropical wet forest. Biotropica 41:234240.CrossRefGoogle Scholar
MCGLYNN, T., CHOI, H., MATTINGLY, S., UPSHAW, A., POIRSON, E. & BETZELBERGER, J. 2009b. Spurious and functional correlates of the isotopic composition of a generalist across a tropical rainforest landscape. BMC Ecology 9:23.CrossRefGoogle ScholarPubMed
MEZGER, D. & PFEIFFER, M. 2010. Is nest temperature an important factor for niche partitioning by leaf-litter ants (Hymenoptera: Formicidae) in Bornean rain forests? Journal of Tropical Ecology 26:445455.CrossRefGoogle Scholar
MOORE, J., BERLOW, E., COLEMAN, D., RUITER, P., DONG, Q., HASTINGS, A., JOHNSON, N., MCCANN, K., MELVILLE, K. & MORIN, P. 2004. Detritus, trophic dynamics and biodiversity. Ecology Letters 7:584600.CrossRefGoogle Scholar
POWERS, J. S., MONTGOMERY, R. A., ADAIR, E. C., BREARLEY, F. Q., DEWALT, S. J., CASTANHO, C. T., CHAVE, J., DEINERT, E., GANZHORN, J. U., GILBERT, M. E., GONZ·LEZ-ITURBE, J. A., BUNYAVEJCHEWIN, S., GRAU, H. R., HARMS, K. E., HIREMATH, A., IRIARTE-VIVAR, S., MANZANE, E., OLIVEIRA, A. A. D., POORTER, L., RAMANAMANJATO, J.-B., SALK, C., VARELA, A., WEIBLEN, G. D. & LERDAU, M. T. 2009. Decomposition in tropical forests: a pan-tropical study of the effects of litter type, litter placement and mesofaunal exclusion across a precipitation gradient. Journal of Ecology 97:801811.CrossRefGoogle Scholar
SCHMITZ, O. J., HAMBACK, P. A. & BECKERMAN, A. P. 2000. Trophic cascades in terrestrial systems: a review of the effects of carnivore removals on plants. American Naturalist 155:141153.CrossRefGoogle ScholarPubMed
SEASTEDT, T. 1984. The role of microarthropods in decomposition and mineralization processes. Annual Review of Entomology 29:2546.CrossRefGoogle Scholar
SHURIN, J. B., BORER, E. T., SEABLOOM, E. W., ANDERSON, K., BLANCHETTE, C. A., BROITMAN, B., COOPER, S. D. & HALPERN, B. S. 2002. A cross-ecosystem comparison of the strength of trophic cascades. Ecology Letters 5:785791.CrossRefGoogle Scholar
SRIVASTAVA, D. S., CARDINALE, B. J., DOWNING, A. L., DUFFY, J. E., JOUSEAU, C., SANKARAN, M. & WRIGHT, J. P. 2009. Diversity has stronger top-down than bottom-up effects on decomposition. Ecology 90:10731083.CrossRefGoogle ScholarPubMed
TOWNSEND, A., ASNER, G. & CLEVELAND, C. 2008. The biogeochemical heterogeneity of tropical forests. Trends in Ecology and Evolution 23:424431.CrossRefGoogle ScholarPubMed
WIEDER, W. R., CLEVELAND, C. C. & TOWNSEND, A. R. 2009. Controls over leaf litter decomposition in wet tropical forests. Ecology 90:33333341.CrossRefGoogle ScholarPubMed
WILSON, E. O. 2005. Oribatid mite predation by small ants of the genus Pheidole. Insectes Sociaux 52:263265.CrossRefGoogle Scholar
WOOD, T., LAWRENCE, D. & CLARK, D. 2006. Determinants of leaf litter nutrient cycling in a tropical rain forest: soil fertility versus topography. Ecosystems 9:700710.CrossRefGoogle Scholar
WYMAN, R. L. 1998. Experimental assessment of salamanders as predators of detrital food webs: effects on invertebrates, decomposition and the carbon cycle. Biodiversity and Conservation 7:641650.CrossRefGoogle Scholar