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Species Synchrony and Its Drivers: Neutral and Nonneutral Community Dynamics in Fluctuating Environments

Michel Loreau and Claire de Mazancourt
The American Naturalist
Vol. 172, No. 2 (August 2008), pp. E48-E66
DOI: 10.1086/589746
Stable URL:
Page Count: 19
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Abstract: Independent species fluctuations are commonly used as a null hypothesis to test the role of competition and niche differences between species in community stability. This hypothesis, however, is unrealistic because it ignores the forces that contribute to synchronization of population dynamics. Here we present a mechanistic neutral model that describes the dynamics of a community of equivalent species under the joint influence of density dependence, environmental forcing, and demographic stochasticity. We also introduce a new standardized measure of species synchrony in multispecies communities. We show that the per capita population growth rates of equivalent species are strongly synchronized, especially when endogenous population dynamics are cyclic or chaotic, while their long‐term fluctuations in population sizes are desynchronized by ecological drift. We then generalize our model to nonneutral dynamics by incorporating temporal and nontemporal forms of niche differentiation. Niche differentiation consistently decreases the synchrony of species per capita population growth rates, while its effects on the synchrony of population sizes are more complex. Comparing the observed synchrony of species per capita population growth rates with that predicted by the neutral model potentially provides a simple test of deterministic asynchrony in a community.

Notes and References

This item contains 26 references.

Literature Cited
  • ['Armstrong, R. A., and R. McGehee. 1980. Competitive exclusion. American Naturalist 115:151–170.']
  • ['Bjørnstad, O. N., R. A. Ims, and X. Lambin. 1999. Spatial population dynamics: analyzing patterns and processes of population synchrony. Trends in Ecology & Evolution 14:427–432.']
  • ['Brown, J. H., E. J. Bedrick, S. K. M. Ernest, J.‐L. E. Cartron, and J. F. Kelly. 2004. Constraints on negative relationships: mathematical causes and ecological consequences. Pages 298–308 in M. L. Taper and S. R. Lele, eds. The nature of scientific evidence: statistical, philosophical, and empirical considerations. University of Chicago Press, Chicago.']
  • ['Chesson, P. 2000. Mechanisms of maintenance of species diversity. Annual Review of Ecology and Systematics 31:343–366.']
  • ['Doak, D. F., D. Bigger, E. K. Harding, M. A. Marvier, R. E. O’Malley, and D. Thomson. 1998. The statistical inevitability of stability‐diversity relationships in community ecology. American Naturalist 151:264–276.']
  • ['Engen, S., R. Lande, B.‐E. Sæther, and T. Bregnballe. 2005. Estimating the pattern of synchrony in fluctuating populations. Journal of Animal Ecology 74:601–611.']
  • ['Ernest, S. K. M., and J. H. Brown. 2001. Homeostasis and compensation: the role of species and resources in ecosystem stability. Ecology 82:2118–2132.']
  • ['Hooper, D. U., F. S. Chapin III, J. J. Ewel, A. Hector, P. Inchausti, S. Lavorel, J. H. Lawton, et al. 2005. Effects of biodiversity on ecosystem functioning: a consensus of current knowledge. Ecological Monographs 75:3–35.']
  • ['Houlahan, J. E., D. J. Currie, K. Cottenie, G. S. Cumming, S. K. M. Ernest, C. S. Findlay, S. D. Fuhlendorf, et al. 2007. Compensatory dynamics are rare in natural ecological communities. Proceedings of the National Academy of Sciences of the USA 104:3273–3277.']
  • ['Hubbell, S. P. 2001. The unified neutral theory of biodiversity and biogeography. Princeton University Press, Princeton, NJ.']
  • ['Hughes, J. B., and J. Roughgarden. 1998. Aggregate community properties and the strength of species’ interactions. Proceedings of the National Academy of Sciences of the USA 95:6837–6842.']
  • ['Ives, A. R. 1995. Measuring resilience in stochastic systems. Ecological Monographs 65:217–233.']
  • ['Ives, A. R., and J. B. Hughes. 2002. General relationships between species diversity and stability in competitive communities. American Naturalist 159:388–395.']
  • ['Ives, A. R., K. Gross, and J. L. Klug. 1999. Stability and variability in competitive communities. Science 286:542–544.']
  • ['Lande, R., S. Engen, and B.‐E. Sæther. 2003. Stochastic population dynamics in ecology and conservation. Oxford University Press, Oxford.']
  • ['Lawton, J. H. 1988. Population dynamics: more time means more variation. Nature 334:563.']
  • ['Levins, R. 1979. Coexistence in a variable environment. American Naturalist 114:765–783.']
  • ['Loreau, M. 2000. Biodiversity and ecosystem functioning: recent theoretical advances. Oikos 91:3–17.']
  • ['Loreau, M., S. Naeem, P. Inchausti, J. Bengtsson, J. P. Grime, A. Hector, D. U. Hooper, et al. 2001. Biodiversity and ecosystem functioning: current knowledge and future challenges. Science 294:804–808.']
  • ['May, R. M., and G. F. Oster. 1976. Bifurcations and dynamic complexity in simple ecological models. American Naturalist 110:573–599.']
  • ['McCann, K. S. 2000. The diversity‐stability debate. Nature 405:228–233.']
  • ['McNaughton, S. J. 1977. Diversity and stability of ecological communities: a comment on the role of empiricism in ecology. American Naturalist 111:515–525.']
  • ['Steele, J. H. 1985. A comparison of terrestrial and marine ecological systems. Nature 313:355–358.']
  • ['Tilman, D. 1999. The ecological consequences of changes in biodiversity: a search for general principles. Ecology 80:1455–1474.']
  • ['Vasseur, D. A., and U. Gaedke. 2007. Spectral analysis unmasks synchronous and compensatory dynamics in plankton communities. Ecology 88:2058–2071.']
  • ['Yachi, S., and M. Loreau. 1999. Biodiversity and ecosystem productivity in a fluctuating environment: the insurance hypothesis. Proceedings of the National Academy of Sciences of the USA 96:1463–1468.']