Considerations on Some Ecological Principles

  • Oscar Ravera
Part of the NATO Conference Series book series (NATOCS, volume 7)


In this paper, I discuss certain fundamental concepts about which there is yet no general agreement among ecologists. The text consists of three parts: (1) the ecosystem, (2) the community, and (3) diversity and stability. In (1), I compare the ecosystem and continuum concepts and cite cases supporting each. All ecosystems are subject to energy and material inputs. To establish clear boundaries limiting an ecosystem and community often is very difficult. For this reason, I review a spectrum of examples--from those best corresponding to the ecosystem scheme to those best corresponding to the continuum concept. Between these extremes, are many intermediate cases, which probably form the majority. In (2), I compare the community as a system of interrelated species with the community defined as a unit formed by all species living in the same physical environment. In addition, I discuss the nature and the value of the relationships among different species and different trophic levels. In (3), I focus on the concept and the evaluation of diversity and on the concept of stability and the relationships between diversity and stability. To better understand these concepts, more information and more collaboration between plant, animal, and microbial ecologists are necessary. The future of applied ecology will depend upon the progress made in studies of these fundamental concepts of ecology.


Energy Flow Reef Fish Oligotrophic Lake Catchment Basin Continuum Concept 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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References Cited

  1. Baldi, E., 1951. Stabilité dans le temps de la biocénose zooplantique du Lac Majeur. Verh. Int. Ver. Limnol. 11: 35–40.Google Scholar
  2. Barret, G.W.P., 1969. The effect of an acute insecticide stress on a semi-enclosed grassland ecosystem. Ecology 49: 1019–1035.CrossRefGoogle Scholar
  3. Bossone, A., and E.V. Tonolli., 1954. Il problema della convivenzaGoogle Scholar
  4. de Arctodiaptomus bacillifer (Koelb.), di Acanthodiaptomus denticornis (Wierz.) e di Heterocope saliens (Lill.). Mem. Ist. Ital. Idrobiol. 8:81–94.Google Scholar
  5. Braun-Blanquet, J., 1951. Pflanzernsociologíe. Grundzüge der vegetationskunde. Springer, Wien, Austria.Google Scholar
  6. Choat, J.H., 1969. Studies on labroid fishes. Ph.D. Dissert. Univ. Queensland, Brisbane, Queensland, Australia.Google Scholar
  7. Clements, F.E., and V.E. Shelford., 1939. Bio-ecology. Wiley, New York, NY USA.Google Scholar
  8. Cody, M.L., 1973. Competition and the structure of bird communities. Princeton Univ. Press, Princeton, NJ USA.Google Scholar
  9. D’Ancona, U., 1942. Relazione sulle ricerche idrobiologiche e idrografiche compiute nel Lago di Nemi. Int. Rev. Hydrobiol. 41: 235.Google Scholar
  10. Elton, C.S., 1958. The ecology of invasions by animals and plants. Methuen, London, England.Google Scholar
  11. Fox, J.F., 1978. Forest fires and the snowshoe hare-Canada lynx cycle. Oecología 31: 349–374.CrossRefGoogle Scholar
  12. Gleason, H.A., 1939. The individualistic concept of the plant association. Am. Midl. Nat. 21: 92–110.CrossRefGoogle Scholar
  13. Golley, F.B., 1960. Energy dynamics of a food chain of an old-field community. Ecol. Monogr. 30: 187–208.CrossRefGoogle Scholar
  14. Hughes, B.D., 1978. The influence of factors other than pollution on the value of Shannon’s diversity index for benthic macro-invertebrates in streams. Water Res. 12: 359–364.CrossRefGoogle Scholar
  15. Hurlbert, S.H., 1971. The non-concept of species diversity: A critique and alternative parameters. Ecology 52: 577–586.CrossRefGoogle Scholar
  16. Hutchinson, G.E., 1951. Copepodology for ornitologists. Ecology 32: 571–577.CrossRefGoogle Scholar
  17. Janzen, D.H., 1968. Host plants as islands in evolutionary and contemporary time. Am. Nat. 102: 592–595.CrossRefGoogle Scholar
  18. Janzen, D.H., 1973. Host plants as islands. II. Competition in evolutionary time. Am. Nat. 107: 786–790.CrossRefGoogle Scholar
  19. Johnson, L.K., and S. Hubbell., 1975. Contrasting foraging strategies and coexistence of two bee species on a single resource. Ecology 56: 1398–1406.CrossRefGoogle Scholar
  20. Jones, R.S., 1968. Ecological relationships in Hawaiian and Johnston Island Acanthuridae (surgen-fishes). Micronesica (J. Coll. Guam) 4: 309–361.Google Scholar
  21. Margalef, R., 1968. Perspectives in ecological theory. Univ. Chicago Press, Chicago, IL USA.Google Scholar
  22. Margalef, R., 1974. Ecologia. Omega, Barcelona, Spain.Google Scholar
  23. May, R.M., 1971a. Stability in model ecosystems. Proc. Ecol. Soc. Aust. 6: 18–56.Google Scholar
  24. May, R.M., 1971b. Stability in multispecies community models. Bull. Math. Bíophys. 12: 59–79.Google Scholar
  25. May, R.M., 1972. Will a large complex system be stable? Nature 238: 413–414.PubMedCrossRefGoogle Scholar
  26. May, R.M., 1975. Patterns of species abundance and diversity. Pages 81–120 in M.L. Cody and J.M. Diamond, eds. Ecology and evolution of communities. Belknap Press, Cambridge, MA USA.Google Scholar
  27. Maynard Smith, J., 1975. Models in ecology. Cambridge Univ. Press, Cambridge, England.Google Scholar
  28. McArthur, R.H., 1955. Fluctuations of animals populations and a measure of community stability. Ecology 36: 533–536.CrossRefGoogle Scholar
  29. Odum, E.P., 1973. Fundamentals of ecology. Saunders, Philadel-phia, PA USA.Google Scholar
  30. Odum, E.P., 1975. Diversity as a function of energy flow. Pages 11–14 in W.H. van Dobben and R.H. Lowe-McConnell, eds. Unifying principles in ecology. Junk, The Hague, The Netherlands.Google Scholar
  31. Orians, G.H., 1975. Diversity, stability and maturity in natural ecosystems. Pages 139–150 inW.H. van Dobben and R.H. Lowe-McConnell, eds. Unifying principles in ecology. Junk, The Hague, The Netherlands.Google Scholar
  32. Patten, B.C., 1963. Plankton: Optimum diversity structure of a summer community. Science 170: 894–898.CrossRefGoogle Scholar
  33. Ramonsky, L.G., 1926. Die Grundgesetzmassigkeíten im aufbau der vegetationsdecke. Bot. Centbl. N.S. 7: 453–455.Google Scholar
  34. Rayera, O., 1951. Velocità di corrente e insediamenti bentonicí. Studio su una lanca del fiume Toce. Mem. Ist. Ital. Idrobiol 6: 221–267.Google Scholar
  35. Rayera, O., 1966. Stability and pattern of distribution of the benthos in different habitats of an alpine oligotrophic lake: Lunzer Untersee. Verh. Int. Ver. Limnol. 16: 233–244.Google Scholar
  36. Rayera, O., 1977. Effects of eutrophication on the zooplankton of a subalpine lake: Lake Lugano. Pages 97–104 inW.K. Downey and G. Ni. Uíd, eds. Lake pollution prevention control. Natl. Scí. Counc., Dublin, Ireland.Google Scholar
  37. Rayera, O., 1980. L’ecosistema. Pages 101–159 in VI Seminarío sull’evoluzione biologica. Ecologia ed etologia. Contrib. Cent. Línceo Interdiscipl. Sci. Mat. Appl. 51, Accad. Naz. Líncei, Roma, Italia.Google Scholar
  38. Rayera, O., 1981. Alcune considerazioni sull’ecosistema. Pages 35–40 inA. Moroni and O. Rayera, eds. Ecologia. Edizioni Zara, Parma, Italia.Google Scholar
  39. Rouch, R., 1982. The budget karsic system. XIII. Comparison of the Harpacticoidea drift at the input and output of the aquifer. Ann. Limnol. 18: 133–150.CrossRefGoogle Scholar
  40. Rouch, R., and L. Bonnet., 1976. Le système karsique du Baget. IV. Premières données sur la structure et l’organization de la communauté des Harpacticides. Ann. Spéléol. 31: 27–41.Google Scholar
  41. Sale, P.F., and R. Dybdahi., 1975. Determinants of community structure for coral reef fishes in an experimental habitat. Ecology 56: 1343–1365.CrossRefGoogle Scholar
  42. Seifert, R.P., 1975. Clumps of Heliconiainfluorescences as ecological islands. Ecology 56: 1416–1422.CrossRefGoogle Scholar
  43. Terborgh, J., 1971. Distribution on environmental gradients: Theory and a preliminary interpretation of distributional patterns in the avifauna of the Cordillera Vilcabamba, Peru. Ecology 52: 23–40.CrossRefGoogle Scholar
  44. Tonolli, V., 1962. L’attuale situazione del popolamento planctonico del Lago Maggiore. Mem. Ist. Ital. Idrobiol. 15: 81–133.Google Scholar
  45. Tourenq, J.N., and F. Dauba., 1978. Transformation de la faune des poissons dans la rivière Lot. Ann. Limnol. 14: 133–138.CrossRefGoogle Scholar
  46. Trojan, P., 1968. Energy flow through a population of Microtus arvalis(Pall.) in an agrocenosis during a period of mass occurrence. Pages 267–279 inK. Petrusewicz and L. Ryszkowski, eds. Energy flow through small mammal population. Pol. Sci. Publ., Warsaw, Poland.Google Scholar
  47. Uhlmann, D., 1978. Hydrobiology. Wiley, New York, NY USA.Google Scholar
  48. Underwood, A.J., 1978. An experimental evaluation of competition between three species of intertidal Prosobranch Gastropods. Oecologia 33: 185–202.CrossRefGoogle Scholar
  49. Ward, J.V., 1975. Bottom fauna-substrate relationships in a Northern Colorado trout stream: 1945–1974. Ecology 56: 1429–1434.CrossRefGoogle Scholar
  50. Watt, K.E.F., 1968. Ecology and resource management. McGraw-Hill, New York, NY USA.Google Scholar
  51. Watt, K.E.F., 1973. Principles of environmental science. McGraw-Hill, New York, NY USA.Google Scholar
  52. White, T.C.R., 1978. The importance of a relative shortage of food in animal ecology. Oecologia 33: 71–86.CrossRefGoogle Scholar
  53. Whittaker, R.H., 1951. A criticism of the plant association and climatic climax concept. Northwest Sci. 25: 17–31.Google Scholar
  54. Whittaker, R.H., 1962. Classification of natural communities. Bot. Rev. 28: 1–239.Google Scholar

Copyright information

© Plenum Press, New York 1984

Authors and Affiliations

  • Oscar Ravera
    • 1
  1. 1.Department of Physical and Natural SciencesCommission of the European Communities Joint Research CentreIspra (Varese)Italy

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