Vegetatio

, Volume 83, Issue 1–2, pp 35–47 | Cite as

A new model for the continuum concept

  • M. P. Austin
  • T. M. Smith
Article

Abstract

A reformulation of the continuum concept is presented after considering the implications of the community/continuum controversy and current niche theory. Community is a spatial concept dependent on landscape pattern while the continuum is an environmental concept referring to an abstract space. When applying niche theory to plants, the mechanisms of competition are ill-defined and the assumption of bell-shaped response curves for species unrealistic.

Eight testable propositions on the pattern of response of vegetation to environmental gradients are presented 1. Environmental gradients are of two types. a) resource gradients or b) direct physiological gradients. 2. The fundamental niche response of species to resource gradients is a series of similar nested response curves. 3. The fundamental niche response of species to direct gradients is a series of separate, independent, overlapping response curves. 4. Species fundamental response curves are such that they have a relative performance advantage in some part of the environmental space. 5. The shape of the realized niche is variable even bimodal but predictable from the fundamental response given the other species present. Propositions 6–8 describe the response shapes of emergent community properties to environmental gradient; species richness is bimodal, dominance trimodal and standing crop unimodal. Detailed comparisons of these propositions are made with the alternative theories of Ellenberg, Gauch and Whittaker, Grime, and Tilman. These theories are incomplete lacking several generally accepted properties of plants and vegetation.

Keywords

Environmental gradient Fundamental niche Niche theory Realized niche Species response curve 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. AustinM. P. 1980. Searching for a model for use in vegetation analysis. Vegetatio 42: 11–21.Google Scholar
  2. AustinM. P. 1982. Use of a relative physiological performance value in the prediction of performance in multispecies mixtures from monoculture performance. J. Ecol. 70: 559–570.Google Scholar
  3. AustinM. P. 1985. Continuum concept, ordination methods, and niche theory. Ann. Rev. Ecol. Syst. 16: 39–61.Google Scholar
  4. AustinM. P. 1986. The theoretical basis of vegetation science. TREE 1: 161–164.Google Scholar
  5. AustinM. P. 1987. Models for analysis of species' response to environmental gradients. Vegetatio 69: 35–45.Google Scholar
  6. Austin, M. P. in press. Community theory and competition in vegetation. In: Tilman, D. & Grace, J. B. (eds), Perspectives in plant competition, Academic Press, London.Google Scholar
  7. AustinM. P. & AustinB. O. 1980. Behaviour of experimental plant communities along a nutrient gradient. J. Ecol. 68: 891–918.Google Scholar
  8. AustinM. P., GrovesR. H., FrescoL. M. F. & KayeP. E. 1985. Relative growth of six thistle species along a nutrient gradient with multispecies competition. J. Ecol. 73: 667–684.Google Scholar
  9. BazzazF. A. 1979. The physiological ecology of plant succession. Ann. Rev. Ecol. Syst. 10: 351–371.Google Scholar
  10. BradshawA. D., ChadwickM. J., JowettD. & SnaydonR. W. 1964. Experimental investigations into the mineral nutrition of several grass species IV Nitrogen level. J. Ecol. 52: 665–676.Google Scholar
  11. BrownJ. M. 1981. Two decades of homage to Santa Rosalia: toward a general theory of diversity. Amer. Zool. 21: 877–888.Google Scholar
  12. BryantJ. P., ChapinIIIF. S. & KleinD. R. 1983. Carbon/nutrient balance of boreal plants in relation to vertebrate herbivory. Oikos 40: 357–368.Google Scholar
  13. ChapinF. S. 1980. The mineral nutrition of wild plants. Ann. Rev. Ecol. Syst. 11: 233–260.Google Scholar
  14. CottamG. & McIntoshR. P. 1966. Vegetation continuum. Science 152: 546–547.Google Scholar
  15. DaubenmireR., 1966. Vegetation: identification of typical communities. Science 151: 291–298.Google Scholar
  16. EllenbergH., 1953. Physiologisches und ökologisches Verhalten derselben Pflanzenarten. Ber. Deutsch. Bot. Ges. 65: 351–62.Google Scholar
  17. EllenbergH. 1954. Uber einige Fortschritte der kausalen Vegetationskunde. Vegetatio 5/6: 199–211.Google Scholar
  18. EllenbergH. 1988. Vegetation ecology of central Europe. 4th. ed; Cambridge University Press. Cambridge.Google Scholar
  19. GauchH. G. & WhittakerR. H. 1972. Coenocline simulation. Ecology 53: 446–51.Google Scholar
  20. GaudetC. L. & KeddyP. A. 1988. A comparative approach to predicting competitive ability from plant traits. Nature 334: 242–243.Google Scholar
  21. GillerP. S. 1984. Community structure and the niche Chapman & Hall, London.Google Scholar
  22. GleasonH. A. 1926. The individualistic concept of the plant association. Bull. Torrey Bot. Club 53: 1–20.Google Scholar
  23. GoodallD. W. 1963. The continuum and the individualistic association. Vegetatio 11: 297–316.Google Scholar
  24. GraceJ. B. 1988. The effects of plant age on the ability to predict mixture performance from monoculture growth. J. Ecol. 76: 152–156.Google Scholar
  25. GrimeJ. P. 1973. Control of species density in herbaceous vegetation. J. Envir. Manage. 1: 151–167.Google Scholar
  26. GrimeJ. P. 1977. Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory. Amer. Nat. 111: 1169–1194.Google Scholar
  27. GrimeJ. P. 1979. Plant strategies and vegetation processes. J. Wiley & Sons, Chichester.Google Scholar
  28. GrubbP. J. 1987. Global trends in species richness in terrestrial vegetation: a view from the northern hemisphere. In: GeeJ. M. R. & GillerP. S. (eds), Organisation of communities past and present. Blackwell, Oxford.Google Scholar
  29. HustonM. 1979. A general hypothesis of species diversity. Amer. Nat. 113: 81–101.Google Scholar
  30. HustonM. & SmithT. M. 1987. Plant succession: Life history and competition. Amer. Nat. 130: 160–198.Google Scholar
  31. MacIntoshR. P. 1967. The continuum concept of vegetation. Bot. Rev. 33: 130–187.Google Scholar
  32. MargulesC. R., NichollsA. O. & AustinM. P. 1987. Diversity of Eucalyptus species predicted by a multi-variable environmental gradient. Oecologia 71: 229–232.Google Scholar
  33. MinchinP. 1989. Montane vegetation of the Mt. Field Massif, Tasmania: a test of some hypotheses about properties of community patterns. Vegetatio 83: 97–110.Google Scholar
  34. Mueller-DomboisD. & EllenbergH. 1974. Aims and methods of vegetation ecology. J. Wiley & Sons, New York.Google Scholar
  35. OriansG. H. & SolbrigO. T. 1977. A cost-income model of leaves and roots with special reference to arid and semiarid areas. Amer. Nat. 111: 677–690.Google Scholar
  36. ParsonsR. F. 1968. The significance of growth-rate comparisons for plant ecology. Amer. Nat. 102: 295–297.Google Scholar
  37. PrenticeI. C. & van derMaarelE. (eds), 1987. Theory and models in vegetation science. Vegetation 69. Junk, Dordrecht.Google Scholar
  38. RussellE. W. 1973. Soil conditions and plant growth. Longmans, London.Google Scholar
  39. SmithT. M. & HustonM. 1989. A functional classification of plant types: linking spatial and temporal pattern in plant communities. Vegetatio 83: 49–69.Google Scholar
  40. TilmanD. 1982. Resource competition and community structure. Princeton Univ. Press, Princeton.Google Scholar
  41. TilmanD. 1987. Secondary succession and the pattern of plant dominance along experimental nitrogen gradients. Ecol. Monogr. 57: 189–214.Google Scholar
  42. TilmanD. 1988. Plant strategies and the structure and dynamics of plant communities. Princeton Univ. press, Princeton.Google Scholar
  43. WesthoffV. & van derMaarelE. 1978. The Braun-Blanquet approach. In: WhittakerR. H. (ed.), Classification of plant communities', Junk, The Hague.Google Scholar
  44. WhittakerR. H. 1967. Gradient analysis of vegetation. Biol. Rev. 42: 207–264.Google Scholar
  45. WhittakerR. H. (ed.) 1978. Ordination of plant communities. Junk, The Hague.Google Scholar
  46. WilsonS. D. & KeddyP. A. 1985. Plant zonation on a shoreline gradient: physiological response curves of component species. J. Ecol. 73: 851–860.Google Scholar

Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • M. P. Austin
    • 1
  • T. M. Smith
    • 2
  1. 1.Division of Wildlife & EcologyCSIROCanberraAustralia
  2. 2.Ecosystems Dynamics Group, Research School of Biological SciencesAustralian National UniversityCanberraAustralia

Personalised recommendations