Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Disentangling nestedness from models of ecological complexity

Abstract

Complex networks of interactions are ubiquitous1 and are particularly important in ecological communities, in which large numbers of species exhibit negative (for example, competition or predation) and positive (for example, mutualism) interactions with one another. Nestedness in mutualistic ecological networks is the tendency for ecological specialists to interact with a subset of species that also interact with more generalist species2. Recent mathematical and computational analysis has suggested that such nestedness increases species richness3,4. By examining previous results and applying computational approaches to 59 empirical data sets representing mutualistic plant–pollinator networks, we show that this statement is incorrect. A simpler metricthe number of mutualistic partners a species hasis a much better predictor of individual species survival and hence, community persistence. Nestedness is, at best, a secondary covariate rather than a causative factor for biodiversity in mutualistic communities. Analysis of complex networks should be accompanied by analysis of simpler, underpinning mechanisms that drive multiple higher-order network properties.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Real networks exhibit a wide range of nestedness and connectance.
Figure 2: Adding mutualistic interactions to models of real networks decreases persistence and this decrease is not related to nestedness.
Figure 3: The number of mutualistic partners is a robust and consistent metric of species viability in mutualistic networks.

References

  1. 1

    Proulx, S. R., Promislow, D. E. L. & Phillips, P. C. Network thinking in ecology and evolution. Trends Ecol. Evol. 20, 345–353 (2005)

    Article  Google Scholar 

  2. 2

    Almeida-Neto, M., Guimaraes, P., Guimaraes, P. R., Loyola, R. D. & Ulrich, W. A consistent metric for nestedness analysis in ecological systems: reconciling concept and measurement. Oikos 117, 1227–1239 (2008)

    Article  Google Scholar 

  3. 3

    Bastolla, U. et al. The architecture of mutualistic networks minimizes competition and increases biodiversity. Nature 458, 1018–1020 (2009)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Thebault, E. & Fontaine, C. Stability of ecological communities and the architecture of mutualistic and trophic networks. Science 329, 853–856 (2010)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Saavedra, S., Stouffer, D. B., Uzzi, B. & Bascompte, J. Strong contributors to network persistence are the most vulnerable to extinction. Nature 478, 233–235 (2011)

    ADS  CAS  Article  Google Scholar 

  6. 6

    Klein, A. M. et al. Importance of pollinators in changing landscapes for world crops. Proc. R. Soc. B 274, 303–313 (2007)

    Article  Google Scholar 

  7. 7

    Bascompte, J., Jordano, P., Melian, C. J. & Olesen, J. M. The nested assembly of plant-animal mutualistic networks. Proc. Natl Acad. Sci. USA 100, 9383–9387 (2003)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Atmar, W. & Patterson, B. D. The measure of order and disorder in the distribution of species in fragmented habitat. Oecologia 96, 373–382 (1993)

    ADS  Article  Google Scholar 

  9. 9

    Rezende, E. L., Lavabre, J. E., Guimaraes, P. R., Jordano, P. & Bascompte, J. Non-random coextinctions in phylogenetically structured mutualistic networks. Nature 448, 925–926 (2007)

    ADS  CAS  Article  Google Scholar 

  10. 10

    Bastolla, U., Lassig, M., Manrubia, S. C. & Valleriani, A. Biodiversity in model ecosystems, I: coexistence conditions for competing species. J. Theor. Biol. 235, 521–530 (2005)

    MathSciNet  Article  Google Scholar 

  11. 11

    May, R. M. Stability and Complexity in Model Ecosystems. (Princeton Univ. Press, 1973)

    Google Scholar 

  12. 12

    Allesina, S. & Tang, S. Stability criteria for complex ecosystems. Nature 483, 205–208 (2012)

    ADS  CAS  Article  Google Scholar 

  13. 13

    Flores, C. O., Meyer, J. R., Valverde, S., Farr, L. & Weitz, J. S. Statistical structure of host-phage interactions. Proc. Natl Acad. Sci. USA 108, E288–E297 (2011)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Kondoh, M., Kato, S. & Sakato, Y. Food webs are built up with nested subwebs. Ecology 91, 3123–3130 (2010)

    Article  Google Scholar 

  15. 15

    Zhang, F., Hui, C. & Terblanche, J. S. An interaction switch predicts the nested architecture of mutualistic networks. Ecol. Lett. 14, 797–803 (2011)

    Article  Google Scholar 

  16. 16

    Vermaat, J. E., Dunne, J. A. & Gilbert, A. J. Major dimensions in food-web structure properties. Ecology 90, 278–282 (2009)

    Article  Google Scholar 

  17. 17

    Williams, R. J. Simple MaxEnt models explain food web degree distributions. Theor. Ecol. 3, 45–52 (2010)

    Article  Google Scholar 

  18. 18

    Williams, R. J. Biology, methodology or chance? The degree distributions of bipartite ecological networks. PLoS ONE 6, e17645 (2011)

    ADS  CAS  Article  Google Scholar 

  19. 19

    Wiggins, S. Introduction to Applied Nonlinear Dynamical Systems and Chaos. 2nd edn (Springer, 2003)

    MATH  Google Scholar 

  20. 20

    Zar, J. H. Biostatistical Analysis. 4th edn (Prentice Hall, 1999)

    Google Scholar 

  21. 21

    Long, J. S. Regression Models for Categorical and Limited Dependent Variables. (Sage Publications, 1997)

    MATH  Google Scholar 

Download references

Acknowledgements

We thank D. Franks, D. Kelly, R. Law, D. Stouffer, C. Thomas and J. Tylianakis for discussions and constructive criticisms, and J.Williams for independent verification of numerical results. M.J.P., A.J. and J.W.P. were supported by the Royal Society of New Zealand Marsden Fund, grant number 08-UOC-034. J.W.P. acknowledges the support of the University of Canterbury Erskine Programme.

Author information

Affiliations

Authors

Contributions

All authors contributed equally to this work.

Corresponding author

Correspondence to Alex James.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Text and Data, Supplementary Tables 1-2, Supplementary Figures 1-8 and Supplementary References. (PDF 840 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

James, A., Pitchford, J. & Plank, M. Disentangling nestedness from models of ecological complexity. Nature 487, 227–230 (2012). https://doi.org/10.1038/nature11214

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing