Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Environmental Variation, Stochastic Extinction, and Competitive Coexistence

Peter B. Adler and John M. Drake
The American Naturalist
Vol. 172, No. 5 (November 2008), pp. E186-E195
DOI: 10.1086/591678
Stable URL: http://www.jstor.org/stable/10.1086/591678
Page Count: 10
  • Download PDF
  • Cite this Item
Environmental Variation, Stochastic Extinction, and Competitive Coexistence
We're having trouble loading this content. Download PDF instead.

Abstract

Abstract: Understanding how environmental fluctuations affect population persistence is essential for predicting the ecological impacts of expected future increases in climate variability. However, two bodies of theory make opposite predictions about the effect of environmental variation on persistence. Single‐species theory, common in conservation biology and population viability analyses, suggests that environmental variation increases the risk of stochastic extinction. By contrast, coexistence theory has shown that environmental variation can buffer inferior competitors against competitive exclusion through a storage effect. We reconcile these two perspectives by showing that in the presence of demographic stochasticity, environmental variation can increase the chance of extinction while simultaneously stabilizing coexistence. Our stochastic simulations of a two‐species storage effect model reveal a unimodal relationship between environmental variation and coexistence time, implying maximum coexistence at intermediate levels of environmental variation. The unimodal pattern reflects the fact that the stabilizing influence of the storage effect accumulates rapidly at low levels of environmental variation, whereas the risk of extinction due to the combined effects of environmental variation and demographic stochasticity increases most rapidly at higher levels of variation. Future increases in environmental variation could either increase or decrease an inferior competitor’s expected persistence time, depending on the distance between the present level of environmental variation and the optimal level anticipated by this theory.

Notes and References

This item contains 34 references.

Literature Cited
  • ['Ackerly, D., and W. Cornwell. 2007. A trait‐based approach to community assembly: partitioning of species trait values into within‐ and among‐community components. Ecology Letters 10:135–145.']
  • ['Adler, P. B., J. HilleRisLambers, P. Kyriakidis, Q. Guan, and J. M. Levine. 2006. Climate variability has a stabilizing effect on coexistence of prairie grasses. Proceedings of the National Academy of Sciences of the USA 103:12793–12798.']
  • ['Adler, P. B., J. HilleRisLambers, and J. M. Levine. 2007. A niche for neutrality. Ecology Letters 10:95–104.']
  • ['Adondakis, S., and D. L. Venable. 2004. Dormancy and germination in a guild of Sonoran Desert annuals. Ecology 85:2582–2590.']
  • ['Alvarez, L. 2001. Does increased stochasticity speed up extinction? Journal of Mathematical Biology 43:534–544.']
  • ['Andrewartha, H. G., and L. C. Birch. 1954. The distribution and abundance of animals. University of Chicago Press, Chicago.']
  • ['Bai, Y., X. Han, J. Wu, Z. Chen, and L. Li. 2004. Ecosystem stability and compensatory effects in the Inner Mongolia grassland. Nature 431:181–184.']
  • ['Boyce, M. 1992. Population viability analysis. Annual Review of Ecology and Systematics 23:481–497.']
  • ['Boyce, M., C. Haridas, C. Lee, C. Boggs, E. Bruna, T. Coulson, D. Doak, et al. 2006. Demography in an increasingly variable world. Trends in Ecology & Evolution 21:141–148.']
  • ['Cáceres, C. E. 1997. Temporal variation, dormancy, and coexistence: a field test of the storage effect. Proceedings of the National Academy of Sciences of the USA 94:9171–9175.']
  • ['Cavender‐Bares, J., D. D. Ackerly, D. A. Baum, and F. A. Bazzaz. 2004. Phylogenetic overdispersion in Floridian oak communities. American Naturalist 163:823–843.']
  • ['Chesson, P. 1990. Geometry, heterogeneity and competition in variable environments. Philosophical Transactions of the Royal Society B: Biological Sciences 330:165–173.']
  • ['———. 2000. Mechanisms of maintenance of species diversity. Annual Review of Ecology and Systematics 31:343–366.']
  • ['Chesson, P., and N. Huntly. 1989. Short‐term instabilities and long‐term community dynamics. Trends in Ecology & Evolution 4:293–298.']
  • ['Chesson, P. L., and R. R. Warner. 1981. Environmental variability promotes coexistence in lottery competitive environments. American Naturalist 117:923–943.']
  • ['Cohen, D. 1966. Optimizing reproduction in a randomly varying environment. Journal of Theoretical Biology 12:119–129.']
  • ['Connell, J. H. 1980. Diversity and the coevolution of competitors, or the ghost of competition past. Oikos 35:131–138.']
  • ['Drake, J. 2005. Population effects of increased climate variation. Proceedings of the Royal Society B: Biological Sciences 272:1823–1827.']
  • ['Facelli, J., P. Chesson, and N. Barnes. 2005. Differences in seed biology of annual plants in arid lands: a key ingredient of the storage effect. Ecology 86:2998–3006.']
  • ['Higgins, S. I., S. T. A. Pickett, and W. J. Bond. 2000. Predicting extinction risks for plants: environmental stochasticity can save declining populations. Trends in Ecology & Evolution 15:516–520.']
  • ['Hutchinson, G. E. 1961. The paradox of the plankton. American Naturalist 95:137–145.']
  • ['Karl, T. R., and K. E. Trenberth. 2003. Modern global climate change. Science 302:1719–1723.']
  • ['Lande, R. 1993. Risks of population extinction from demographic and environmental stochasticity and random catastrophes. American Naturalist 142:911–927.']
  • ['Levine, J. M., and M. Rees. 2004. Effects of temporal variability on rare plant persistence in annual systems. American Naturalist 164:350–363.']
  • ['Lewontin, R., and D. Cohen. 1969. On population growth in a randomly varying environment. Proceedings of the National Academy of Sciences of the USA 62:1056–1060.']
  • ['Menges, E. 2000. Population viability analyses in plants: challenges and opportunities. Trends in Ecology & Evolution 15:51–56.']
  • ['Morris, W. F., and D. F. Doak. 2003. Quantitative conservation biology: theory and practice of population viability analysis. Sinauer, Sunderland, MA.']
  • ['Pake, C. E., and D. E. Venable. 1995. Is coexistence of Sonoran Desert annuals mediated by temporal variability in reproductive success? Ecology 76:246–261.']
  • ['Salinger, M. 2005. Climate variability and change: past, present and future: an overview. Climatic Change 70:9–29.']
  • ['Thompson, J. 1999. The evolution of species interactions. Science 284:2116–2118.']
  • ['Tilman, D. 2004. Niche trade‐offs, neutrality, and community structure: a stochastic theory of resource competition, invasion, and community assembly. Proceedings of the National Academy of Sciences of the USA 101:10854–10861.']
  • ['Tilman, D., and J. Downing. 1994. Biodiversity and stability in grasslands. Nature 367:363–365.']
  • ['Venable, D. L., and J. S. Brown. 1988. The selective interactions of dispersal, dormancy, and seed size as adaptations for reducing risk in variable environments. American Naturalist 131:360–384.']
  • ['Warner, R. R., and P. L. Chesson. 1985. Coexistence mediated by recruitment fluctuations: a field guide to the storage effect. American Naturalist 125:769–787.']