Skip to main content
SpringerLink
Log in

The importance of seed dispersal in the Alexandria Coastal Dunefield, South Africa

  • Published:
Journal of Coastal Conservation Aims and scope Submit manuscript

Abstract

The endozoochorous dispersal of seeds by mammals and birds between distinct vegetation communities was assessed to determine the importance of these processes in coastal dune field management. Isolated pockets of thicket vegetation (bush-pockets) within a large coastal dune field provided the opportunity to study vertebrate seed dispersal and its contribution to their origin and maintenance. Mammalian and avian faeces were collected for the quantification of seeds dispersed via endozoochory. Birds and mammals showed considerable overlap, dispersing intact seeds of 17 and 29 plant species, respectively, but mammals dispersed a greater diversity and size range than birds. Extrapolation of mammalian faecal data indicates an annual input of 23 million intact seeds to the dune field. Significantly more seeds are deposited by mammals and birds in the bush-pockets than on open sand, and birds deposited greater numbers of seeds nearer the seed source. Zoochory appears to be critical for the maintenance of the bush-pocket habitats through the dispersal of climax woody plant species into the dune field. Directional dispersal by birds and mammals to the bush-pockets is considered to be responsible for the maintenance and possible origin of these bush-pockets. The high number of exotic plant propagules dispersed by both avian and mammalian zoochory highlights the importance of management of the Alexandria Coastal Dunefield (ACD) beyond the reserve boundaries. In a dynamic system such as the ACD which is within a declared nature reserve, the continued existence of the bush-pockets may depend on the maintenance, beyond the reserve boundaries, of a reservoir of not only plant material but vertebrate dispersers as well.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

ACD:

Alexandria Coastal Dunefield

References

  • Arnold, T.H. & De Wet, B.C. 1993. Plants of southern Africa: names and distribution.Mem Bot. Surv. S. Afr. 62: 1–825.

    Google Scholar 

  • Ascaray, C.M. 1986.An ecological study of the hairy-footed gerbil, Gerbillurus paeba, in an eastern Cape dunefield. M. Sc. Thesis, University of Port Elizabeth.

  • Avis, A.M. 1989. A review of coastal dune stabilization in the Cape Province of South Africa.Landscape Urban Plan. 18: 55–68.

    Article  Google Scholar 

  • Bate, G.C. & Dobkins, G.S. 1992. The interactions between sand, aeolianite and vegetation in a large coastal transgressive dune sheet. In: Carter, R.W.G., Curtis, T.G.F. & Sheehy-Skeffington, M.J. (eds.)Coastal dunes—Geomorphology, ecology and management for conservation, pp. 139–152. Proceedings of the Third European Dune Congress Galway/ Ireland/ 17–21 June 1992. A.A. Balkema, Rotterdam.

    Google Scholar 

  • Bothma, J. Du P. 1971. Food ofCanis mesomelas in South Africa,Zool. Afr. 6: 195–203.

    Google Scholar 

  • Breytenbach, G.J. & Skinner, J.D. 1981. Diet, feeding and habitat utilization by bush-pigsPotamochoerus porcus Linnaeus.S. Afr. J. Wildl. Res. 12: 1–7.

    Google Scholar 

  • Brown, C.A. 1990.Avifauna community structure in coastal dune bush pockets. M. Sc. Thesis, University of Port Elizabeth.

  • Brown, C.A., Kerley, G.I.H., McLachlan, A. & Wooldridge, T. 1995. The insular biogeography of birds in coastal dune bush patches.S. Afr. J. Wildl. Res. 25: 113–117.

    Google Scholar 

  • Bruton, J.-S. 1992.Seed dispersal by birds in the Alexandria dunefield. M. Sc. Thesis, University of Port Elizabeth.

  • Castley, J.G., Kerley, G.I.H. 2001. Biotic processes in coastal dunefields: An assessment of seed removal, with non-native seed removal experiments.J. Coastal Conserv. 7: 49–56.

    Article  Google Scholar 

  • Chapman, C.A. 1989. Primate seed dispersal: The fate of dispersed seeds.Biotropica 21: 148–154.

    Article  Google Scholar 

  • d’Antonio, C.M. 1990. Seed production and dispersal in the non-native, invastive succulentCarpobrotus edulis (Aizoaceae) in coastal strand communities of central California.J. Appl. Ecol. 27: 693–702.

    Article  Google Scholar 

  • Debussche, M. & Isenmann, P. 1989. Fleshy fruit characters and the choices of bird and mammal seed dispersers in a Mediterranean region.Oikos 56: 327–338.

    Article  Google Scholar 

  • Foord, S.H., van Aarde, R.J. & Ferreria, S.M. 1994. Seed dispersal by vervet monkeys in rehabitlitating coastal dune forests at Richards Bay.S. Afr. J. Wildl. Res. 24: 56–59.

    Google Scholar 

  • French, K. 1991. Characteristics and abundance of vertebrate-dispersed fruits in temperate wet sclerophyll forest in southeastern Australia.Aust. J. Ecol. 16: 1–13.

    Article  Google Scholar 

  • Frost, P.G.H. 1980. Fruit-frugivore interactions in a South African coastal dune forest. In: Nohhring, R. (ed)Proceedings of the 17th International Ornithological Congress, pp. 1179–1184. Deutsche Ornithologen Gesellschaft, Berlin.

    Google Scholar 

  • Gautier-Hion, A., Duplantier, J.-M., Quris, R., Feer, F., Sourd, C., Decoux, J.-P., Dubost, G., Emmons, L., Erard, C., Hecketsweiler, P., Moungazi, A., Roussilhon, C. & Thiollay, J.-M. 1985. Fruit characters as a basis of fruit choice and seed dispersal in a tropical forest vertebrate community.Oecologia (Berl.) 65: 324–337.

    Article  Google Scholar 

  • Gill, A.M. 1985.Acacia cyclops G. Don (Leguminosae-Mimosaceae) in Australia: Distribution and dispersal.J. R. Soc. W. Aust. 67: 59–65.

    Google Scholar 

  • Glyphis, J.P., Milton, S.J. & Siegfried, W.R. 1981. Dispersal ofAcacia cyclops by birds.Oecologia (Berl.) 48: 138–141.

    Article  Google Scholar 

  • Hamilton, W.D. & May, R.M. 1977. Dispersal in stable habitats.Nature 269: 578–581.

    Article  Google Scholar 

  • Heinrich, B. 1976. Flowering phenologies: Bog, woodland, and disturbed habitats.Ecology 57: 890–899.

    Article  Google Scholar 

  • Herrera, C.M. 1984. Adaptation to frugivory of Mediterranean avian seed dispersers.Ecology 65: 609–617.

    Article  Google Scholar 

  • Herrera, C.M. 1989. Frugivory and seed dispersal by carnivorous mammals, and associated fruit characteristics, in undisturbed Mediterranean habitats.Oikos 55: 250–262.

    Article  Google Scholar 

  • Hiscocks, K. & Perrin, M.R. 1987. Feeding observation of black-backed jackal in an arid coastal environment.S. Afr. J. Wildl. Res. 17: 55–58.

    Google Scholar 

  • Hoffman, M.T. 1989. A preliminary investigation of the phenology of subtropical thicket and karroid shrubland in the lower Sundays River valley, SE Cape.S. Afr. J. Bot. 55: 586–597.

    Google Scholar 

  • Howe, H.F. 1979. Fear and frugivory.Am. Nat. 114: 925–931.

    Article  Google Scholar 

  • Howe, H.F. 1980. Monkey dispersal and waste of a neotropical fruit.Ecology 61: 944–959.

    Article  Google Scholar 

  • Howe, H.F. & Primack, R.B. 1975. Differential seed dispersal by birds of the treeCasearia nitida (Flacourtiaceae).Biotropica 7: 278–283.

    Article  Google Scholar 

  • Howe, H.F. & Smallwood, J. 1982. Ecology of seed dispersal.Annu. Rev. Ecol. Syst. 13: 201–228.

    Article  Google Scholar 

  • Huenneke, L.F. & Vitousek, P.M. 1990. Seeding and clonal recruitment of the invasive treePsidium cattleianum: Implications for management of native Hawaiian forests.Biol. Conserv. 53: 199–211.

    Article  Google Scholar 

  • Illenberger, W.K. 1986.The Alexandria coastal dunefield: Morphology, sand budget and history. M.Sc. Thesis, University of Port Elizabeth.

  • Janson, C.H. 1983. Adaptations of fruit morphology to dispersal agents in a neotropical forest.Science 219: 187–189.

    Article  Google Scholar 

  • Janzen, D.H. 1984. Dispersal of small seeds by big herbivores: Foliage is the fruit.Am. Nat. 123: 338–353.

    Article  Google Scholar 

  • Kerley, G.I.H., McLachlan, A. & Castley, J.G. 1996. Diversity and dynamics of bush-pockets in the Alexandria Coastal Dunefield, South Africa.Landscape Urban Plan. 34: 255–266.

    Article  Google Scholar 

  • Knight, R.S. 1988.Aspects of plant dispersal in the southwestern Cape with particular reference to the roles of birds as dispersal agents. Ph.D. Thesis, University of Cape Town.

  • Knight, R.S. & Macdonald, I.A.W. 1991. Acacias and korhaans: an artificially assembled seed dispersal system.S. Afr. J. Bot. 57: 220–225.

    Google Scholar 

  • Knight, R.S. & Siegfried, W.R. 1983. Inter-relationships between type, size and colour of fruits and dispersal in Southern African trees,Oecologia 56: 405–412.

    Article  Google Scholar 

  • Liversidge, R. 1972. A preliminary study of on fruit production in certain plants.Ann. Cape. Prov. Mus. (Nat. Hist.) 9: 51–63.

    Google Scholar 

  • Maclean, G.L. 1993.Roberts’ Birds of Southern Africa. John Voelcker Bird Book Fund, Cape Town.

    Google Scholar 

  • Mares, M.A. & Rosenzweig, M.L. 1978. Granivory in North and South American deserts: Rodents, birds and ants.Ecology 59: 235–241.

    Article  Google Scholar 

  • McDonnell, M.J. & Stiles, E.W. 1983. The structural complexity of old field vegetation and the recruitment of bird-dispersed plant species.Oecologia 56: 109–116.

    Article  Google Scholar 

  • McKey, D. 1975. The ecology of coevolved seed dispersal systems. In: Gilbert, L.E. & Raven, P. (eds.)Coevolution of animals and plants, pp. 159–191. University of Texas Press, Austin, TX.

    Google Scholar 

  • McLachlan, A. 1991. Ecology of coastal dune fauna.J. Arid Environ. 21: 229–243.

    Google Scholar 

  • McLachlan, A., Ascaray, C. & du Toit, P. 1987. Sand movement, vegetation succession and biomass spectrum in a coastal dune slack in Algoa Bay, South Africa.J. Arid. Environ. 12: 9–25.

    Google Scholar 

  • McLachlan, A., Siebens, P. & Ascaray, C.M. 1982. Survey of a major coastal dunefield in the eastern Cape.Univ. Port Elizabeth Zool. Dept. Rep. Ser. 10: 1–48.

    Google Scholar 

  • Middlemiss, E. 1963. The distribution ofAcacia cyclops in the Cape peninsula area by birds and other mammals.S. Afr. J. Sci. 59: 419–420.

    Google Scholar 

  • Noss, R.F. 1983. A regional landscape approach to maintain biodiversity.Bioscience 33: 700–706.

    Article  Google Scholar 

  • Phillips, J.F.V. 1926. ‘Wild pig’ (Potamochoerus choeropotamus) at the Knysna: Notes by a naturalist.S. Afr. J. Sci. 23: 655–660.

    Google Scholar 

  • Phillips, J.F.V. 1927. The role of the ‘bushdove’Columba arguatrix T. and K., in fruit-dispersal in the Knysna forests.S. Afr. J. Sci. 24: 435–440.

    Google Scholar 

  • Rowe-Rowe, D.T. 1983. Black-backed jackal diet in relation to food availability in the Natal DrakensbergS. Afr. J. Wildl. Res. 13: 17–23.

    Google Scholar 

  • Siegfried, W.R. 1992. Conservation status of the South African endemic avifauna.S. Afr. J. Wildl. Res. 22: 61–64.

    Google Scholar 

  • Siegfried, W.R. & Brown, C.A. 1992. The distribution and protection of mammals endemic to southern Africa.S. Afr. J. Wildl. Res. 22: 11–16.

    Google Scholar 

  • Skinner, J.D. & Smithers, R.H.N. 1990.The mammals of the Southern African subregion. New Ed. University of Pretoria. Pretoria.

    Google Scholar 

  • Snow, D.W. 1981a. Coevolution of birds and plants In: Forey, P.C. (ed.)Evolving biosphere.

  • Snow, D.W. 1981b. Tropical frugivorous birds and their food plants: a world survey.Biotropica 13: 1–14.

    Article  Google Scholar 

  • Stiles, E.W. 1982. Fruit flags, Two hypotheses.Am. Nat. 120: 500–509.

    Article  Google Scholar 

  • Sutton, G.M. 1951. Dispersal of mistletoe by birds.Willson Bull. 63: 235–237.

    Google Scholar 

  • Talbot, M.M.B. & Bate, G.C. 1991. The structure of vegetation in bush-pockets of transgressive coastal dunefields.S. Afr. J. Bot. 57: 156–160.

    Google Scholar 

  • Thompson, J.N. 1981. Eliasomes and fleshy fruits: phenology and selection pressures for ant-dispersed seeds.Am. Nat. 117: 104–108.

    Article  Google Scholar 

  • Tinley, K.L. 1985. Coastal dunes of South Africa.S. Afr. Natl. Sci. Prog. Rep. 109: 150–189.

    Google Scholar 

  • van der Pijl L. 1972.Principles of dispersal in higher plants. 2nd ed, Springer, Berlin.

    Google Scholar 

  • Walker, B.H. 1992. Biodiversity and ecological redundancy.Conserv. Biol. 6: 18–23.

    Article  Google Scholar 

  • Walker, C. 1988.Signs of the wild. 4th ed. Struik Publishers, Cape Town.

    Google Scholar 

  • Walsberg, G.E. 1975. Digestive adaptations ofPhainopepla nitens associated with the eating of mistletoe berries.The Condor 77: 169–174.

    Article  Google Scholar 

  • Wheelright, N.T. & Janson, C.H. 1985. Colors of fruit displays of bird dispersed plants in two tropical forests.Am. Nat. 126: 777–799.

    Article  Google Scholar 

  • Willson, M.F. 1993. Mammals as seed-dispersal mutualists in North America.Oikos 67: 159–167.

    Article  Google Scholar 

  • Willson, M.F. & Whelan, C.J. 1990. The evolution of fruit color in fleshy-fruited plants.Am. Nat. 136: 790–809.

    Article  Google Scholar 

  • Winterbottom, J.M. 1970. The birds of the alien Acacia thickets of the south western Cape.Zool. Afr. 5: 49–57.

    Google Scholar 

  • Wynberg, R. 1993. The convention on biological diversity. In:Exploring the earth summit-findings of the Rio United Nations Conference on environment and development: implications for South Africa, pp. 111–121. Penrose Press, Johannesburg.

    Google Scholar 

  • Young, M.M. 1987.The Alexandria dunefield vegetation. M.Sc. Thesis, University of Port Elizabeth.

  • Zar, J.H. 1984.Biostatistical analysis. 2nd ed. Prentice-Hall, Inc., Englewood Cliffs, NJ.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Terrestrial Ecology Research Unit, Department of Zoology, University of Port Elizabeth, P. O. Box 1600, 6000, Port Elizabeth, South Africa

    Castley J. G., Bruton J.-S & Kerley G. I. H.

  2. South African National Parks, Humewood 6013, P. O. Box 20419, Port Elizabeth, South Africa

    McLachlan A. (Dean)

  3. College of Science, Sultan Qaboos University, 123, Al Khod, Sultanate of Oman

    McLachlan A. (Dean)

Authors
  1. Castley J. G.
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Bruton J.-S
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Kerley G. I. H.
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. McLachlan A.
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Castley J. G..

Rights and permissions

Reprints and permissions

About this article

Cite this article

Castley, J.G., Bruton, JS., Kerley, G.I.H. et al. The importance of seed dispersal in the Alexandria Coastal Dunefield, South Africa. J Coast Conserv 7, 57–70 (2001). https://doi.org/10.1007/BF02742468

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02742468

Key words

Nomenclature

Search

Navigation