Abstract
Cynodon dactylon (L.) Pers. forms extensive meadows on seasonally inundated areas of the Pongolo river floodplain. As floodwaters receded during winter, the shoots of C. dactylon which had not decomposed during submergence sprouted. Crop growth rate was high (up to 23 kg/ha/d dry mass) and the meadows were heavily grazed by domestic stock which removed up to 15 kg/ha/d. The high crop growth rate was not maintained because as exposure period increased, soils became dry and water stress conditions developed. This caused the C. dactylon to become less palatable and brought about a shift in grazing which allowed a build-up of the grazeable and ungrazeable fraction standing crop. Maximum standing crop occurred at the onset of the next flood. Grazing is shown to have a net negative effect on production, although at different times during exposure defoliation had either a depressing or stimulating effect on growth. It is postulated that the duration of the inundation period is more significant than the duration of the exposure period in maintaining the C. dactylon meadows.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Attwell, R. I. G., 1970. Some effects of Lake Kariba on the ecology of a floodplain of the mid-Zambezi valley of Rhodesia. Biol. Conserv. 2: 189–196.
Brown, D., 1954. Methods of Surveying and Measuring Vegetation. Commonwealth Bureau of Pastures and Field Crops, Bul. 42, Farnham Royal, Bucks, England.
Furness, H. D., 1981. The plant ecology of seasonally flooded areas of the Pongolo river floodplain with particular reference to Cynodon dactylon (L.) Pers. Unpublished PhD thesis, Department of Botany, University of Natal, Pietermaritzburg, South Africa.
Furness,H. D. & C. M. Breen, 1980. The vegetation of seasonally flooded areas of the Pongolo river floodplain. Bothalia 13: 217–231.
Furness, H. D. & C. M. Breen, 1982. Decomposition of Cynodon dactylon (L.) Pers. in the seasonally flooded areas of the Pongolo river floodplain: Pattern and significance of dry matter and nutrient loss. 10750obiologia 97: 119–126.
Heeg, J. & C. M. Breen,1982. Man and the Pongolo floodplain. South African National Scientific Programmes Report 56. C.S.I.R., Pretoria, South Africa.
Hunt, R., 1978. Plant Growth Analysis. Studies in Biology No. 96. Edward Arnold, London.
Kumar, A. & M. C. Joshi, 1972. Effects of grazing on the structure and productivity of the vegetation near Pilani, Rajasthan, India. J. Ecol. 60: 665–674.
McKell, C. M., A. M. Wilson & M. B. Jones, 1961. A flotation method for easy separation of roots from soil samples. Agron. J. 53: 56–57.
McNaughton, S. J., 1979. Grassland-herbivore dynamics. In A. R. E. Sinclair & M. Norton-Griffiths (eds.), Serengeti: Dynamics of an ecosystem. University of Chicago Press, Chicago.
Meredith, D., 1955. The grasses and pastures of South Africa. Central News Agency, Cape Town.
Milner, C. & R. E. Hughes, 1968. Methods for the measurement of the primary production of grasslands. IBP Handbook No. 6. Blackwell Scientific Publications, Oxford.
Owen-Smith, N., 1982. Factors influencing the consumption of plant products by large herbivores. In B. J. Huntley & B. H. Walker (eds.), Ecology of tropical savannas. Springer-Verlag, Berlin.
Pieczýnska, E., 1975. Ecological interactions between land and the littoral zones of lakes (Maruian Lakeland, Poland). In A. D. Hasler (ed.), Coupling of Land and Water Systems. Springer-Verlag, Berlin - Heidelberg - New York: pp. 263–276.
Scotcher, J. S. B., D. R. M. Stewart & C. M. Breen, 1978. The diet of the hippopotamus in Ndumu Game Reserve, Natal, as determined by faecal analysis. S. Afr. J. Wildl. Res. 8: 1–11.
Sheppe, W. & T. Osborne, 1971. Patterns of use of a floodplain by Zambian mammals. Ecol. Monogr. 41: 179–205.
Tainton, N. M. (ed.), 1981. Veld and pasture management in South Africa. University of Natal Press, Pietermaritzburg.
Vesey-Fitzgerald, D. E., 1963.Central African grasslands. J. Ecol. 51: 243–274.
Welcomme, R. L., 1979. The fisheries ecology of floodplain rivers. Longman, New York.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Furness, H.D., Breen, C.M. Interactions between period of exposure, grazing and crop growth rate of Cynodon dactylon (L.) Pers. in seasonally flooded areas of the Pongolo River floodplain. Hydrobiologia 126, 65–73 (1985). https://doi.org/10.1007/BF00008389
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00008389