Abstract
We compared the invasibility of riparian plant communities high on river banks with those on floodplain floors for four South African rivers. Analyses of abundant and significant riparian species showed that the floors have 3.1 times more exotic plants than the banks. The percent exotics ranges from 5% to 11% of total species richness for the banks, and from 20% to 30% for the floors. Species richness and percent exotics are negatively correlated for the banks, but not correlated for the floors.
Despite great differences in climate, species richness, and landuse history, the percentages of exotic plants in three rivers in the Pacific Northwest of the USA and one river in southwestern France are similar to those in South Africa (24-30% vs. 20-30%, respectively). Furthermore, the high proportions of exotic species in these riparian plant communities are comparable to those reported for vascular plant communities on islands. We conclude that the macro-channel floor regions of the riparian zones of South African rivers are highly vulnerable to invasion by exotic vascular plants.
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Baker, R. G., Bettis, E. A. & Horton, D. G. 1993. Late Wisconsinan early Holocene riparian paleoenvironment in southeastern Iowa. Geol. Soc. Am. Bull. 105: 206–13.
Billen, G., Décamps, H., Garnier, J., Boë t, P., Meybeck, M., & Servais, P. 1995. Atlantic river systems of Europe. Pp. 389–418 In: Cushing, C. E., Cummins, K. W. & Minshall, G. W. (eds.), River and stream ecosystems. Elsevier Science BV, Amsterdam.
Bond, P. & Goldblatt, P. 1984. Plants of the Cape Flora: a descriptive catalogue. National Botanical Gardens of South Africa, Cape Town.
Bowman, D. M. J. S. & McDonough, L. 1991. Tree species distribution across a seasonally flooded elevation gradient in the Australian monsoon tropics. J. Biogeogr. 18: 203–12.
Bredenkamp, G. J. & Van Rooyen, N. 1993a. A survey of the vegetation of the Crocodile River in the Kruger National Park. Ekotrust CC, Pretoria, South Africa.
Bredenkamp, G. J. & Van Rooyen, N. 1993b. A survey of the vegetation of the Letaba River in the Kruger National Park. Ekotrust CC. Pretoria, South Africa.
Bredenkamp, G. J. & Van Rooyen, N. 1993c. A survey of the vegetation of the Olifants River in the Kruger National Park. Ekotrust CC, Pretoria, South Africa.
Bredenkamp, G. J., Van Rooyen, N. & Theron, G. K. 1991. A survey of the riparian vegetation of the Sabie River in the Kruger National Park. Ekotrust CC, Pretoria, South Africa.
Case, T. J. 1990. Invasion resistance arises in strongly interacting species-rich model competition communities. PNAS USA 87: 9610–9614.
Compton, R. H. 1976. The Flora of Swaziland. J. South African Bot. Suppl. No. 11.
Décamps, H. 1993. River margins and environmental change. Ecol. Appl. 3: 441–445.
Décamps, H. & Tabacchi, E. 1992. Species richness in vegetation along river margins. Pp. 1–20. In: Giller, P. S., Hildrew, A. G. & Raffaelli, D. G. (eds), Aquatic Ecology: Scale, Pattern, and Process. Blackwell Scientific Publications, Oxford.
DeFerrari, C. M. & Naiman, R. J. 1994. A multi-scale assessment of the occurrence of exotic plants on the Olympic Peninsula, Washington. J. Veg. Sci. 5: 247–258.
Dyer, R. A. 1975. The genera of Southern African flowering plants. Department of Agricultural and Technical Services, Pretoria, South Africa.
Elton, C. S. 1958. The ecology of invasions by animals and plants. Methuen, London.
Ewel, J. J. 1986. Invasibility: lessons from South Florida. Pp. 214–230. In: Mooney, H. A. & Drake, J. A. (eds), Ecology of biological invasions of North America and Hawaii. Springer-Verlag, New York.
Faber, P. M., Keller, E., Sands, A. & Massey, B. M. 1989. The ecology of riparian habitats of the Southern California coastal region: a community profile. US Dept. of the Interior. Fish & Wildlife Service. Biol. Rept. 85(7.27).
Fabian, A. & Germishuizen, G. 1982. Transvaal wild flowers. MacMillan South Africa Ltd., Johannesburg.
Felt, M. E. 1985. Rivers to Reckon with: rivers on the western edge of the Olympic Peninsula: the Hoh, the Queets, the Clearwater. E. C. Cockerell & C. Fletcher, Forks, Washington.
Forman, R. T. T. & Godron, M. 1986. Landscape ecology. John Wiley & Sons, New York.
Franz, E. H. & Bazzaz, F. A. 1977. Simulation of vegetation response to modified hydrologic regimes: a probabilistic model based on niche differentiation in a floodplain forest. Ecology 58: 176–183.
Gilpin, M. E. & Soulé, M. E. 1986. Minimum viable populations: processes of species extinctions. Pp. 19–35. In: Soulé, M. E. (ed.), Conservation biology: the science of scarcity and diversity. Sinauer Associates, Inc., Sunderland, Mass.
Goodman, D. 1987. The demography of chance extinction. Pp. 11–34. In: Soulé, M. E. (ed.), Viable populations for conservation. Cambridge University Press, Cambridge.
Graf, W. L. 1978. Fluvial adjustments to the spread of tamarisk in the Colorado Plateau region. Geol. Soc. Am. Bull. 89: 1491–1501.
Gregory, S. V., Swanson, F. J., McKee, W. A. & Cummins, K. W. 1991. An ecosystem perspective of riparian zones. BioScience 41: 540–551.
Henderson, J. A., Peter, D. H., Lescher, Shaw, R. D. & Shaw, D. C. 1989. Forested plant associations of the Olympic National Forest. USDA Forest Service Region 6 Ecological Technical Paper 001- 88.
Henderson, L. & Wells, M. J. 1986. Alien plant invasions in the grassland and savanna biomes. Pp. 109–118. In: Macdonald, I. A. W., Kruger, F. J. & Ferrar, A. A. (eds), The ecology and management of biological invasions in Southern Africa. Oxford University Press, Cape Town.
Hitchcock, C. L., Cronquist, A., Ownbey, M. & Thompson, J. W. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press, Seattle.
Hobbs, R. J. 1989. The nature and effects of disturbance relative to invasions. Pp. 389–405. In: Drake, J. A., Mooney, H. A., di Castri, F., Groves, R. H., Kruger, F. J., Rejmánek, M. & Williamson, M. (eds). Biological invasions: a global perspective. John Wiley & Sons, New York.
Junk, W. J., Bayley, P. B. & Sparks, R. E. 1989. The flood pulse concept in river-floodplain systems. In: Dodge, D. P. (ed.), Proceedings of the International Large River Symposium. Can. Sp. Publ. Fish. Aquat. Sci. 106: 110–127.
Kalliola, R. & Puhakka, M. 1988. River dynamics and vegetation mosaicism: a case study of the River Kamajohka, northernmost Finland. J. Biogeogr. 15: 703–719.
Leopold, L. B., Wolman, M. G. & Miller, J. P. 1964. Fluvial processes in geomorphology. Dover Publications, Inc., New York.
Loope, L. L., Sanchez, P. G., Tarr, P.W., Loope, W. L. & Anderson, R. L. 1988. Biological invasions of arid land nature reserves. Biol. Cons. 44: 95–118.
Mabberley, D. J. 1987. The plant book: a portable dictionary of the higher plants. Cambridge University Press, Cambridge.
Macdonald, I. A. W. & Frame, G. W. 1988. The invasion of introduced species into nature reserves in tropical savannas and dry woodlands. Biol. Cons. 44: 67–93.
Macdonald, I. A. W. & Gertenbach, W. P. D. 1988. A list of alien plants in Kruger National Park. Koedoe 31: 137–150.
Macdonald, I. A. W., Graber, D. M., DeBenedetti, S., Groves, R. H. & Fuentes, E. R. 1988. Introduced species in nature reserves in Mediterranean-type climatic regions of the world. Biol. Cons. 44: 37–66.
Macdonald, I. A. W., & Jarman, M. L. 1985. Invasive alien plants in the terrestrial ecosystems of Natal, South Africa. S. Afr. Natl. Sci. Prog. Rpt. 118: 1–88.
Mack, R. N. 1989. Temperate grasslands vulnerable to plant invasions: characteristics and consequences. Pp. 155–179. In: Drake, J. A., Mooney, H. A., di Castri, F., Groves, R. H., Kruger, F. J., Rejmánek, M. & Williamson, M. (eds.). Biological invasions: a global perspective, John Wiley & Sons, New York.
Malanson, G. P. 1993. Riparian landscapes. Cambridge Univerity Press, Cambridge.
Murray, N. L. & Stauffer, D. F. 1995. Nongame bird use of habitat in central Appalachian riparian forests. J.Wildl. Manag. 59: 78–89.
Naiman, R. J. & Décamps, H. 1997. The ecology of interfaces: riparian zones. Ann. Rev. Ecol. Syst. 28: 621–658.
Naiman, R. J. & Rogers, K. H. 1997. Large animals and systemlevel characteristics in river corridors. BioScience 47: 521–529.
Naiman, R. J., Décamps, H. & Pollock, M. 1993. The role of riparian corridors in maintaining regional biodiversity. Ecol. Appl. 3: 209–212.
Naiman, R. J., & Décamps, H. [eds]. 1990. Ecology and management of aquatic-terrestrial ecotones. UNESCO, Paris, and Parthenon Publishing Group, Carnforth, UK.
Peterjohn, W. T. & Correll, D. L. 1984. Nutrient dynamics in an agricultural watershed: observations on the role of a riparian forest. Ecology 65: 1466–1475.
Pimm, S. L. 1989. Theories of predicting success and impact of introduced species. Pp. 351–367. In: Drake, J. A. (ed.), Biological invasions: a global perspective. John Wiley & Sons, Chichester.
Planty-Tabacchi, A. M., Tabacchi, E., Naiman, R. J., DeFerrari, C. & Décamps, H. 1996. Invasibility of species-rich communities in riparian zones. Cons. Biol. 10: 598–607.
Pollock, M. M., Naiman, R. J. & Hanley, T. A. 1998. Plant species richness in riparian wetlands: A test of biodiversity theory. Ecology 79: 94–105.
Pysek, P. & Prach, K. 1994. How important are rivers for supporting plant invasions? Pp. 23–31. In: de Waal, L., Child, L. E., Wade, P. M. & Brock, J. H. (eds), Ecology and management of invasive riverside plants. John Wiley & Sons, New York.
Ramakrishnan, P. S. & Vitousek, P. M. 1989. Ecosystem-level processes and the consequences of biological invasions. Pp. 281–300. In: Drake, J. A. (ed.), Biological invasions: a global perspective John Wiley & Sons, Chichester.
Simberloff, D. 1981. Community effects of introduced species. Pp. 53–83. In: Nitecki, M. H. (ed.), Biotic crises in ecological and evolutionary time. Academic Press, New York.
Simberloff, D. 1988. The contribution of population and community biology to conservation science. Ann. Rev. Ecol. Syst. 19: 473–511.
Tabacchi, E., Planty-Tabacchi, A. M. & Décamps, O. 1990. Continuity and discontinuity of the riparian vegetation along a fluvial corridor. Landscape Ecol. 5: 9–20.
Usher, M. B. 1988. Biological invasions of nature reserves: a search for generalizations. Biol. Cons. 44: 119–135.
Usher, M. B., Kruger, F. J., Macdonald, I. A. W., Loope, L. L. & Brockie, R. E. 1988. The ecology of biological invasions into nature reserves: an introduction. Biol. Cons. 44: 1–8.
van Coller, A. L., Rogers, K. H., & Heritage, G. L. 1997. Linking riparian vegetation types and fluvial geomorphology along the Sabie River within the Kruger National Park, South Africa. Afr. J. Ecol. 35: 194–212.
van Coller, A. L. & Rogers, K. H. 1995. Riparian vegetation of the Sabie River: relating spatial distribution patterns to characteristics of the physical environment. Centre for Water in the Environment, Report No. 1/95. University of the Witwatersrand, Johannesburg.
van Niekerk, A. W. & Heritage, G. L. 1993. Geomorphology of the Sabie River: overview and classification. Centre for Water in the Environment, Report No. 2. University of theWitwatersrand, Johannesburg.
Vitousek, P. M. 1986. Biological invasions and ecosystem properties: can species make a difference? Pp. 163–176. In: Mooney, H. A. & Drake, J. A. (eds), Ecology of biological invasions of North America and Hawaii. Springer-Verlag, New York.
Wells, M. J., Poynton, R. J., Balsinhas, A. A., Musil, K. J., Joffe, H., van Hoepen, E. & Abbott, S. K. 1986. The history of introduction of invasive alien plants to southern Africa. Pp. 21–36. In: Macdonald, I. A. W., Kruger, F. J., & Ferrar, A. A. (eds), The ecology andmanagement of biological invasions in Southern Africa. Oxford University Press, Cape Town.
Wissmar, R. C. & Swanson, F. J. 1990. Landscape disturbances and lotic ecotones. Pp. 65–89. In: Naiman, R. J. & Décamps, H. (eds), The Ecology and Management of Aquatic-Terrestrial Ecotones. UNESCO, Paris and The Parthenon Publishing Group, Carnforth, UK.
Zembal, R. 1984. Survey of vegetative and vertebrate fauna in the Prado Basin and the Santa Ana River Canyon, CA. US Army Corps of Engineers, Los Angeles.
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Hood, W.G., Naiman, R.J. Vulnerability of riparian zones to invasion by exotic vascular plants. Plant Ecology 148, 105–114 (2000). https://doi.org/10.1023/A:1009800327334
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DOI: https://doi.org/10.1023/A:1009800327334