Journal of Genetics

, Volume 62, Issue 1, pp 33–47 | Cite as

Can a single resource support many consumer species ?

  • Sulochana Gadgil
  • Madhav Gadgil


The conclusion that the number of species co-existing within a biological community cannot exceed the number of limiting factors is not valid if we assume that (i) the relative efficiency of two competing species in utilizing a resource is not independent of the resource density, but one species may be more efficient at a lower density and less efficient at a higher density and (ii) there is a spatial or temporal heterogeneity in the density of the resource. This spatial or temporal heterogeneity does not have to be furnished by factors external to the biological community, but may be generated within the biological community itself as in the case of a vertical gradient of light in a plant community. This possibility of a stable co-existence of more than one species in a community limited by a single resource, even when the resource is being supplied uniformly in space and time, is formally demonstrated.


Density Dependent Mortality Resource Density Species Packing 
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  1. 1.
    COHEN, D. (1971). Maximizing final yield when growth is limited by time or by limiting resources. Journal of Theoretical Biology, 33: 299–307.PubMedCrossRefGoogle Scholar
  2. 2.
    GAUSE, G F. (1934). The struggle for existence. Williams & Wilkins, Baltimore, 163p.Google Scholar
  3. 3.
    LEVIN, S A. (1970). Community equilibria and stability, and an extension of the competitive exclusion principle. Amer Nat, 104: 413–423.CrossRefGoogle Scholar
  4. 4.
    LEVINS, R. (1968). Evolution in changing environments. Princeton University Press, Princeton, N J. 130p.Google Scholar
  5. 5.
    MACARTHUR, R H and LEVINS, R. (1964). Competition, habitat selection, and character displacement in a patchy environment. Proc Nat Acad Sci, U S, 51: 1207–1210.CrossRefGoogle Scholar
  6. 6.
    MAY, R R and MACARTHUR, R H. (1972). Niche overlap as a function of environmental variability. Proc Nat Acad Sci, U S, 69: 1109–1113.CrossRefGoogle Scholar
  7. 7.
    ROUGHGARDEN, J. (1971). Density dependent natural selection. Ecology, 52: 453–468.CrossRefGoogle Scholar
  8. 8.
    STEWART, F N and LEVIN, B R. (1973). Partitioning of resources and the outcome of interspecific competition: a model and some general considerations. Amer Nat, 107: 171–198.CrossRefGoogle Scholar
  9. 9.
    VOLTERRA, V. (1931). Lecons sur la theorie mathematique de la lutte pour la vie. Gauthier — Villars. Paris, 214p.Google Scholar

Copyright information

© Indian Academy of Sciences 1975

Authors and Affiliations

  • Sulochana Gadgil
    • 1
  • Madhav Gadgil
    • 1
  1. 1.Centre for Theoretical StudiesIndian Institute of ScienceBangalore

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