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Species diversity enhances ecosystem functioning through interspecific facilitation


Facilitation between species is thought to be a key mechanism by which biodiversity affects the rates of resource use that govern the efficiency and productivity of ecosystems1,2,3,4; however, there is no direct empirical evidence to support this hypothesis. Here we show that increasing the species diversity of a functional group of aquatic organisms induces facilitative interactions, leading to non-additive changes in resource consumption. We increased the richness and evenness of suspension-feeding caddisfly larvae (Insecta, Trichoptera) in stream mesocosms and found that the increased topographical complexity of the benthic habitat alters patterns of near-bed flow such that the feeding success of individuals is enhanced. Species diversity reduces ‘current shading’ (that is, the deceleration of flow from upstream to downstream neighbours), allowing diverse assemblages to capture a greater fraction of suspended resources than is caught by any species monoculture. The fundamental nature of this form of hydrodynamic facilitation suggests that it is broadly applicable to freshwater and marine habitats; in addition, it has several analogues in terrestrial ecosystems where fluxes of energy and matter can be influenced by biophysical complexity3,5,6. Thus, changes in species diversity may alter the probability of positive species interactions, resulting in disproportionately large changes in the functioning of ecosystems.

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Figure 1: Effect of species diversity on resource consumption.
Figure 2: Effect of species diversity on flow.


  1. Hector, A. et al. Plant diversity and productivity experiments in European grasslands. Science 286, 1123–1127 (1999).

    CAS  Article  Google Scholar 

  2. Loreau, M. & Hector, A. Partitioning selection and complementarity in biodiversity experiments. Nature 412, 72–76 (2001).

    ADS  CAS  Article  Google Scholar 

  3. Mulder, C., Uliassi, D. & Doak, D. Physical stress and diversity–productivity relationships: The role of positive interactions. Proc. Natl Acad. Sci. USA 98, 6704–6708 (2001).

    ADS  CAS  Article  Google Scholar 

  4. Tilman, D. et al. Diversity and productivity in a long-term grassland experiment. Science 294, 843–845 (2001).

    ADS  CAS  Article  Google Scholar 

  5. Jones, C. G., Lawton, J. H. & Shachack, M. Positive and negative effects of organisms as physical ecosystem engineers. Ecology 78, 1946–1957 (1997).

    Article  Google Scholar 

  6. Luttge, U. Physiological Ecology of Tropical Plants (Springer, Berlin, 1997).

    Book  Google Scholar 

  7. Naeem, S., Thompson, L. J., Lawler, S. P., Lawton, J. H. & Woodfin, R. M. Declining biodiversity can alter the performance of ecosystems. Nature 368, 734–737 (1994).

    ADS  Article  Google Scholar 

  8. Cardinale, B. J., Nelson, K. & Palmer, M. A. Linking species diversity to the functioning of ecosystems: on the importance of environmental context. Oikos 91, 175–183 (2000).

    Article  Google Scholar 

  9. Chapin, F. S. et al. Consequences of changing biodiversity. Nature 405, 234–242 (2000).

    CAS  Article  Google Scholar 

  10. Tilman, D., Lehman, D. & Thompson, K. Plant diversity and ecosystem productivity: theoretical considerations. Proc. Natl Acad. Sci. USA 94, 1857–1861 (1997).

    ADS  CAS  Article  Google Scholar 

  11. Hooper, D. & Vitousek, P. The effects of plant composition and diversity on ecosystem processes. Science 277, 1302–1305 (1997).

    CAS  Article  Google Scholar 

  12. Huston, M. Hidden treatments in ecological experiments: re-evaluating the ecosystem function of biodiversity. Oecologia 110, 449–460 (1997).

    ADS  Article  Google Scholar 

  13. Wardle, D. A. Is “sampling effect” a problem for experiments investigating biodiversity–ecosystem function relationships? Oikos 87, 403–410 (1999).

    Article  Google Scholar 

  14. Fridley, J. D. The influence of species diversity on ecosystem productivity: how, where, and why? Oikos 93, 514–526 (2001).

    Article  Google Scholar 

  15. Tilman, D. et al. The influence of functional diversity and composition on ecosystem processes. Science 277, 1300–1302 (1997).

    CAS  Article  Google Scholar 

  16. Chapin, S. et al. Ecosystem consequences of changing biodiversity. BioScience 48, 45–52 (1998).

    Article  Google Scholar 

  17. Palmer, M. A. et al. Biodiversity and ecosystem function in freshwater sediments. Ambio 26, 571–577 (1997).

    Google Scholar 

  18. Nowell, A. R. M. & Jumars, P. Flow environments of aquatic benthos. Annu. Rev. Ecol. Syst. 15, 303–328 (1984).

    Article  Google Scholar 

  19. Cardinale, B. J. & Palmer, M. A. Disturbance moderates biodiversity–ecosystem function relationships: evidence from caddisfly assemblages in stream mesocosms. Ecology (in the press).

  20. Loudon, C. & Alstad, D. N. Theoretical mechanisms of particle capture: Predictions for hydropsychid distributional ecology. Am. Nat. 135, 360–381 (1990).

    Article  Google Scholar 

  21. Eckman, J. E., Nowell, A. R. M. & Jumars, P. J. Sediment destabilization by animal tubes. J. Mar. Res. 39, 361–374 (1981).

    Google Scholar 

  22. Johnson, A. Flow around phoronids: Consequences of a neighbor to suspension feeders. Limnol. Oceanogr. 35, 1395–1401 (1990).

    ADS  Article  Google Scholar 

  23. Huettel, M. & Gust, G. Impact of bioroughness on interfacial solute exchange in permeable sediments. Mar. Ecol. Prog. Ser. 89, 253–267 (1992).

    ADS  Article  Google Scholar 

  24. Butman, C. A., Frechette, M., Geyer, W. R. & Starczak, V. R. Flume experiments on food supply to the blue mussel Mytilus edulis L. as a function of boundary-layer flow. Limnol. Oceanogr. 39, 1755–1768 (1994).

    ADS  Article  Google Scholar 

  25. Sebens, K. P., Witting, J. & Helmuth, B. Effects of water flow and branch spacing on particle capture by the reef coral Madracis mirabilis (Duchassaing and Michelotti). J. Exp. Mar. Biol. Ecol. 211, 1–28 (1997).

    Article  Google Scholar 

  26. Hart, D. D. The adaptive significance of territoriality in filter-feeding larval blackflies (Diptera: Simuliidae). Oikos 46, 88–92 (1986).

    Article  Google Scholar 

  27. Englund, G. Asymmetric resource competition in a filter-feeding stream insect (Hydropsyche siltalai: Trichoptera). Freshwat. Biol. 26, 425–432 (1991).

    Article  Google Scholar 

  28. Okamura, B. Microhabitat variation and patterns of colony growth and feeding in a marine bryozoan. Ecology 73, 1502–1513 (1992).

    Article  Google Scholar 

  29. Vogel, S. Life in Moving Fluids (Princeton Univ. Press, Princeton, 1994).

    Google Scholar 

  30. Finnigan, J. Turbulence in plant canopies. Annu. Rev. Fluid Mech. 32, 519–571 (2000).

    ADS  Article  Google Scholar 

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We thank D. Doak, D. Hart, M. Loreau, P. Morin, S. Naeem, K. Sebens, D. Tilman, J. Thomson and T. Welnitz for comments; and S. Brooks for advice on hydrodynamic measurements. This work was supported by grants from the National Science Foundation to M.A.P. and to B.J.C.

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Correspondence to Bradley J. Cardinale.

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Cardinale, B., Palmer, M. & Collins, S. Species diversity enhances ecosystem functioning through interspecific facilitation. Nature 415, 426–429 (2002).

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