Advertisement

Mycorrhizal associations as indicators of forest quality after land use practices

  • N. A. Onguene

Abstract

Counting mycorrhizal infective propagules (spores, fruitbodies, colonized roots) in forest soils was used to assess impacts of shifting cultivation and selective logging on habitat partitioning and abundance of inoculum of arbuscular mycorrhizal and ectomycorrhizal fungi in south Cameroon. Intact soil cores, disturbed soil samples and fruitbodies were collected from late successional forest stands inside and outside the crown projection of ectomycorrhizal clumps, early successional forest stands, fallows of Chromolaena odorata with and without Gnetum lianas, fields of food crops, forestry practices including skid trails and bare soil landings. Fractional mycorrhizal colonisation was assessed by the gridline intersect method. Spores of arbuscular mycorrhizal fungi were extracted by the wet-sieving and decanting method followed by sugar centrifugation and counted under microscope. Fruitbodies of ectomycorrhizal fungi were collected, described in fresh state, dried before microscopic examination and identification.

Due to creation of skid trails, landings and forest roads, selective logging had a very large negative impact on both ectomycorrhizae and arbuscular mycorrhizae (AM) whereas shifting cultivation had only a slight positive effect on arbuscular mycorrhizas and a negative effect on ectomycorrhizae. Both types of mycorrhizal inocula were differently partitioned: AM inoculum was continuous throughout the landscape while ectomycorrhizal inoculum was patchy, suggesting the need for different management approaches for both arbuscular mycorrhizal and ectomycorrhizal forest patches. Ectomycorrhizal forest clumps indicated least disturbed forest stands. Owing to their specific biodiversity, they should be included as indicators of sustainable forest management; Carpophores of ectomycorrhizal fungi classify as sub-indicators in the principles, criteria and indicators of African Timber Organizatio/International Tropical Timber Organization (ATO/IITO)

Keywords

Arbuscular mycorrhizae Ectomycorrhizae and Land use practices 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Alexander I.J. 1987. Ectomycorrhizas in indigenous lowland tropical forest and woodland.7th NACOM, Sylvia D.M., Hung L.L., Graham J.H. (eds). IFAS, Univ. Florida, Gainesville, Fl, May 3–8, 1987, pp. 15–1.Google Scholar
  2. Alexander I., Ahma N. and See L.S. 1992. The role of mycorrhizas in the regeneration of some Malaysian forest trees. Phil. Trans. R. Soc. Lond., ser. B 335: 379–388.CrossRefGoogle Scholar
  3. Anonymous, 2003: ATO/IITO Principles, criteria and indicators for the sustainable management of natural tropical forests. IITO Policy Development Series nˆ14, Yokohama, Japon.Google Scholar
  4. Béreau M., Gazel M. and Garbaye J. 1997. Les symbioses mycorhiziennes des arbres de la forêt tropicale humide de Guyane française. Can. J. Bot. 75: 711–716.Google Scholar
  5. Connell J.H. and Lowman M. 1989. Low-diversity tropical rain forests: some possible mechanisms for their existence. Am. Nat. 134: 88–119.CrossRefGoogle Scholar
  6. Fassi B. and Moser M. 1991. Mycorrhizae in the natural forest of tropical Africa and the Neotropics. In: Fontana A. (ed.), Funghi, Piante e Suolo, Centro di studio Micologia del Consiglio nazionalle delle Ricerche, Torino, Italy, pp. 183–202.Google Scholar
  7. Franqueville A. 1973. Atlas régional sud-ouest. République Unie du Cameroun. ORSTOM, Yaoundé, CamerounGoogle Scholar
  8. Habte M. 1989. Impact of simulated erosion on the abundance and activity of indigenous vesicular-arbuscular mycorrhizal endophytes in an oxisol. Biol.Fertil. Soils. 7: 164–167.CrossRefGoogle Scholar
  9. Hart T.B., Hart J.A. and Murphy P.H. 1989. Mono-dominant and species-rich forests of the humid tropics: causes for their occurrence. Am. Nat. 133: 613–633.CrossRefGoogle Scholar
  10. Letouzey R. 1968. Etude phytogéographique du Cameroun. Ed. P. Le Chevalier, Paris.Google Scholar
  11. Newbery D.M., Alezander I.J., Thomas D.W. and Gartlan J.S. 1988. Ectomycorrhizal rain forest legumes and soil phosphorus in Korup National Park, Cameroon, New Phytol. 109: 367–409.Google Scholar
  12. Newbery D.M., Alezander I.J. and Gartlan J.S. 1997. Phosphorus dynamics in lowland African rain forest: the influence of ectomycorrhizal trees. Ecological Monographs 67(3): 367–409.Google Scholar
  13. Newsham K.K., Fitter A.H. and Watkinson A.R. 1995. Multifunctionality and biodiversity in arbuscular mycorrhizas. Trends Ecol. Evol. 10: 407–411.CrossRefGoogle Scholar
  14. Onguene N.A. 2000. Mycorrhizal diversity and dynamics in south Cameroon.Google Scholar
  15. Onguene N.A. and Kuyper T.H.W. 2001. Mycorrhizal associations in rain forest of south Cameroon. For. Ecol.Manag. 140: 277–287.CrossRefGoogle Scholar
  16. Plenchette C., Fortin J.A. and Furlan V. 1983. Growth response of several plant species to mycorrhizae in a soil of moderate P- fertility. II. Soil fumigation induced stunting of plants corrected by reintroduction of the wild endomycorrhizal flora. Plant and Soil 70: 211–217.CrossRefGoogle Scholar
  17. Sieverding E. 1991. Vesicular-arbuscular mycorrhiza management in tropical agrosystems. Eschborn, Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH.Google Scholar
  18. SPSS Inc. 1993. SPSS – X users’Guide. 4th ed. Gorinchem, the Netherlands.Google Scholar
  19. Torti S.D. and Coley P.D. 1999. Tropical monodominance: a preliminary test of the ectomycorrhizal hypothesis. Biotropica 31: 220–228.CrossRefGoogle Scholar
  20. Torti S.D., Coley P.D. and Kursar T.A. 2001. Causes and consequences of monodominance in tropical lowland forest. Am. Nat. 157:141–153.CrossRefGoogle Scholar
  21. Voorhoeve A.G. 1964. Some notes on the tropical rainforest of the Yoma-Gola national forest near Bomi Hills, Liberia. Commonw. For. Rev. 43: 17–24.Google Scholar
  22. Van Gemerden B.S. and Hazeu G.W. 1999. Landscape ecological survey (1:100 000) of the Bipindi-AkomII-Lolodorf region, Southwest Cameroon. Tropenbos Documents 1: 1–164.Google Scholar
  23. Waterloo M.J., Ntonga J.C., Dolman A.J. and Ayangma A.B. 2000. Impact of land use change on the hydrology and erosion of rain forest land in South Cameroon. DLO Winand Staring Centre Report 134: 1–89.Google Scholar

Copyright information

© Springer 2007

Authors and Affiliations

  • N. A. Onguene
    • 1
  1. 1.Department of Soils, Water & AtmosphereInstitute of Agricultural Research for Development (IRAD)YaoundéCameroon

Personalised recommendations