, Volume 108, Issue 1, pp 79–84

Effect of arbuscular mycorrhiza on inter- and intraspecific competition of two grassland species

Population Ecology


We were interested in the role of arbuscular mycorrhiza (AM) in the competition between plants of different sizes. A pot experiment of factorial design was established, in which AM root colonization and competition were used as treatments. Five-week-old Prunella vulgaris seedlings were chosen as target plants (i.e. plants whose response to competition was studied) and the following (13 replicates of each) were used as neighbours: (1) a large, 10-week-old P. vulgaris, (2) two P. vulgaris seedlings, and (3) a large, 10-week-old Fragaria vesca. In the experiment where small neighbours were grown together with small target plants, competition did not reduce target plant weight significantly, compared to the other two treatments. The competitive effects of large neighbours were significant, regardless of species (both older neighbours reduced the weights of target plants similarly), but there was a clear difference between intra- and interspecific competition when plants were mycorrhizal. In intraspecific competition with a large neighbour, the target plant shoot weight was reduced 24% when inoculated with AM. Thus, AM amplified rather than balanced intraspecific competition. In interspecific competition with old F. vesca, the shoot weights of target plants were 22% greater when inoculated with AM than when non-mycorrhizal. The results showed that, for given soil condition, AM might increase species diversity by increasing competitive intraspecific suppression and decreasing the interspecific suppression of small plants by larger neighbours.

Key words

Arbuscular mycorrhiza Competition Fragaria vesca Prunella vulgaris 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Allen EB, Allen MF (1984) Competition between plants of different successional stages — mycorrhizae as regulators. Can J Bot 62: 2625–2629Google Scholar
  2. Allen EB, Allen MF (1990) The mediation of competition by mycorrhizae in successional and patchy environments. In: Grace JR, Tilman D (eds) Perspectives on plant competition. Academic Press, New York 367–389Google Scholar
  3. Allsopp N, Stock WD (1992) Density dependent interactions between VA mycorrhizal fungi and even-aged seedlings of two perennial Fabaceae species. Oecologia 91: 281–287Google Scholar
  4. Allsopp N, Stock WD (1995) Relationship between seed reserves, seedling growth and mycorrhizal responses in 14 related shrubs (Rosidae) from a low-nutrient environment. Funct Ecol 9: 248–254Google Scholar
  5. Berendse F (1994) Competition between plant populations at low and high nutrient supplies. Oikos 71: 253–260Google Scholar
  6. Bergelson JM, Crawley MJ (1988) Mycorrhizal infection and plant species diversity. Nature 334: 202Google Scholar
  7. Eissenstat DM, Newman EI (1990) Seedling establishment near large plants: effects of vesicular-arbuscular mycorrhizas on the intensity of plant competition. Funct Ecol 4: 95–99Google Scholar
  8. Fitter AH, Nichols R (1988) The use of benomyl to control infection by vesicular-arbuscular mycorrhizal fungi. New Phytol 110: 201–206Google Scholar
  9. Francis R, Read DJ (1984) Direct transfer of carbon between plants connected by vesicular-arbuscular mycorrhizal mycelium. Nature 307: 53–56Google Scholar
  10. Francis R, Read DJ (1994) The contributions of mycorrhizal fungi to the determination of plant community structure. Plant Soil 159: 11–25Google Scholar
  11. Gange AC, Brown VK, Farmer LM (1990) A test of mycorrhizal fungi benefit in an early successional plant community. New Phytol 115: 85–91Google Scholar
  12. Gange AC, Brown VK, Sinclair GS (1993) Vesicular-arbuscular mycorrhizal fungi: a determinant of plant community structure in early succession. Funct Ecol 7: 616–622Google Scholar
  13. Goldberg DE, Landa K (1991) Competitive effect and response: hierarchies and correlated traits in the early stages of competition. J Ecol 79: 1013–1030Google Scholar
  14. Graham JH, Eissenstat DM (1994) Host genotype and the formation and function of VA mycorrhizae Plant Soil 159: 179–185Google Scholar
  15. Grime JP, Mackey JML, Hillier SH, Read DJ (1987) Floristic diversity in a model system using experimental microcosms. Nature 328: 420–422Google Scholar
  16. Grubb PJ (1977) The maintenance of species-richness in plant communities: the importance of the regeneration niche. Biol Rev 52: 107–145Google Scholar
  17. Harley JL, Harley EL (1987) A check-list of mycorrhiza in the British flora. New Phytol 105 [Suppl]: 1–102Google Scholar
  18. Hartnett DC, Hetrick BAD, Wilson GWT, Gibson DJ (1993) Mycorrhizal influence on intra- and interspecific neighbour interactions among co-occurring prairie grasses. J Ecol 81: 787–795Google Scholar
  19. Hartnett DC, Samenus RJ, Fischer LE, Hetrick BAD (1994) Plant demographic responses to mycorrhizal symbiosis in tallgrass prairie. Oecologia 99: 21–26Google Scholar
  20. Hayman DS, Morris EJ, Page RJ (1981) Methods for inoculating field crops with mycorrhizal fungi. Ann Appl Biol 99: 247–253Google Scholar
  21. Jakobsen I (1994) Research approaches to study the functioning of vesicular-arbuscular mycorrhizas in the field. Plant Soil 159: 141–147Google Scholar
  22. Koide RT (1991) Nutrient supply, nutrient demand and plant response to mycorrhizal infection. New Phytol 117: 365–386Google Scholar
  23. Koide RT, Shumway DL, Mabon SA (1994) Mycorrhizal fungi and reproduction of field populations of Abutilon thephrasti Medic. (Malvaceae). New Phytol 126: 123–140Google Scholar
  24. Koske RE, Gemma JN (1989) A modified procedure for staining roots to detect VA mycorrhizas. Mycol Res 92: 486–505Google Scholar
  25. Kull K, Zobel M (1991) High species richness in an Estonian wooded meadow. J Veget Sci 2: 711–714Google Scholar
  26. Newsham KK, Fitter AH, Watkinson AR (1994) Root pathogenic and arbuscular mycorrhizal fungi determine fecundity of asymptomatic plants in the field. J Ecol 82: 805–814Google Scholar
  27. Newsham KK, Watkinson AR, West HM, Fitter AH. (1995) Symbiotic fungi determine plant community structure: changes in a lichen-rich community induced by fungicide application. Funct Ecol 9: 442–447Google Scholar
  28. Paul ND, Ayres PG, Wyness LE (1989) On the use of fungicides for experimentation in natural vegetation. Funct Ecol 3: 759–769Google Scholar
  29. Peng S, Eissenstat DM, Graham JH, Williams K, Hodge NC (1993) Growth depression in mycorrhizal Citrus at high-phosphorus supply. Analysis of carbon costs. Plant Physiol 101: 1063–1071Google Scholar
  30. Rajapakse S, Miller JCJ (1992) Methods for studying vesicular-arbuscular mycorrhizal root colonization and related root physical properties. In: Norris JR, Read DJ, Varma AK (eds) Techniques for the study of mycorrhiza. Academic Press. London 301–316Google Scholar
  31. Reintam L, Kitse E, Piho A, Rooma I, Tarandi K (1962) Mullateadus. Eesti Riiklik Kirjastus, TallinnGoogle Scholar
  32. Roldan-Fajardo BE (1994) Effect of indigenous arbuscular mycorrhizal endophytes on the development of six wild plants colonizing a semi-arid area in south-east Spain. New Phytol 127: 115–121Google Scholar
  33. Summerbell RC (1988) Benomyl-tolerant microfungi associated with mycorrhizae of black spruce. Can J Bot 66: 553–557Google Scholar
  34. Tilman D (1993) Species richness of experimental productivity gradients: how important is colonization limitation? Ecology 74: 2179–2191Google Scholar
  35. Weiner J (1986) How competition for light and nutrients affects size variability in Ipomoea tricolor populations. Ecology 67: 1425–1427Google Scholar
  36. West HM, Fitter AH, Watkinson AR (1993a) The influence of three biocides on the fungal associates of the roots of Vulpia ciliata spp. ambigua under natural conditions. J Ecol 81: 345–350Google Scholar
  37. West HM, Fitter AH, Watkinson AR (1993b) Response of Vulpia ciliata ssp. ambigua to removal of mycorrhizal infection and to phosphate application under natural conditions. J Ecol 81: 351–358Google Scholar
  38. Zobel M, Moora M (1995) Interspecific competition and arbuscular mycorrhiza: importance for the coexistence of two calcareous grassland species. Folia Geobot Phytotaxon 30: 223–230Google Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  1. 1.Department of Botany and EcologyTartu UniversityTartuEstonia

Personalised recommendations