Simulated pattern formation around artificial waterholes in the semi-arid Kalahari

Journal of Vegetation Science

Volumn 8, Issue 2, 1997, Pages 177-188

  Jeltsch, Florian ^a   Milton, Suzanne J ^b   Dean, W Richard J ^b   Van Rooyen, Noel ^c  

^a HELMHOLTZ CENTRE FOR ENVIRONMENTAL RESEARCH UFZ   (Germany)

^b UNIVERSITY OF CAPE TOWN   (South Africa)

^c UNIVERSITY OF PRETORIA   (South Africa)

Author keywords

Grazing; Piosphere; Rangeland degradation; Shrub encroachment; Simulation model; Vegetation change

Indexed keywords

EID: 0031441152     PISSN: 11009233     EISSN: None     Source Type: Journal    
DOI: 10.2307/3237346     Document Type: Article

References (52)

1. Abel, N. 1993. Carrying capacity, rangeland degradation and livestock development policy for the communal rangelands of Botswana. Pastor. Dev. Netw. 35c: 1-9.
2. Abel, N.O.J. & Blaikie, P.M. 1989. Land degradation, stocking rates and conservation policies in the communal rangelands of Botswana and Zimbabwe. Land Degrad. Rehabil. 1: 101-123.
3. Acocks, J.P.H. 1953. Veld types of South Africa. Mem. Bot. Surv. S. Afr. 28: 1-192.
4. Andrew, M.H. 1988. Grazing impact in relation to livestock watering points. Trends Ecol. Evol. 3: 336-339.
5. Archer, S. & Smeins, F.E. 1991. Ecosystem-level processes. In: Heitschmidt, R.K. & Stuth, J.W. (eds.) Grazing management, pp. 109-139. Timber, OR.
6. Barker, J.R., Thurow, T.L. & Herlocker, D.J. 1990. Vegetation of pastoralist campsites within the coastal grassland of central Somalia. Afr. J. Ecol. 28: 291-297.
7. Belsky, A.J. 1994. Influences of trees on savanna productivity: tests of shade, nutrients, and tree-grass competition. Ecology 75: 922-932.
8. Czárán, T. & Bartha, S. 1992. Spatiotemporal dynamic models of plant populations and communities. Trends Ecol. Evol. 7: 38-42.
9. Dean, W.R.J. & Macdonald, I.A.W. 1994. Historical changes in stocking rates of domestic livestock as a measure of semi-arid and arid rangeland degradation in the Cape Province, South Africa. J. Arid Environ. 26: 281-298.
10. Dean, W.R.J., Milton, S.J., Watkeys, M.K. & Hockey, P.A.R. 1991. Distribution, habitat preference and conservation status of red lark Certhilauda burra in Cape Province, South Africa. Biol. Conserv: 58: 257-274.
11. Durett, R. & Levin, S. 1994. The importance of being discrete (and spatial). Theor. Pop. Biol. 46: 363-394.
12. Fouché, H.J., de Jager, J.M. & Opperman, D.P.J. 1985. A mathematical model for assessing the influence of stocking rate on the incidence of drought and for estimating the optimal stocking rates. J. Grassl. Soc. S. Afr. 2: 4-6.
13. Fourie, J.H., van Niekerk, J.W. & Fouché, H.J. 1985. Weidingskapasiteitsnorme in die vrystaatstreek. Glen. Agric. 14: 4-7.
14. Frost, P.G.H. & Robertson, F. 1987. The ecological effect of fire in savannas. In: Walker, B.H. (ed.) Determinants of tropical savannas, pp.93-140. ICSU Press, Miami, FL.
15. Fusco, M., Holechek, J., Tembo, A., Daniel, A. & Cardenas, M. 1995. Grazing influences on watering point vegetation in the Chihuahuan desert. J. Range Manage. 48: 32-38.
16. Grimm, V., Frank, K., Jeltsch, F., Brandi, R., Uchmanski, J. & Wissel, C. 1996. Pattern-oriented modelling in population ecology. Sci. Tot. Environ. 183: 151-166.
17. Hannan, N.P., Prevost, Y., Diouf, A. & Diallo, O. 1991. Assessment of desertification around deep wells in the Sahel using satellite imagery. J. Appl. Ecol. 28: 173-186.
18. Hellden, U. 1991. Desertification - Time for an assessment? Ambio 20: 372-383.
19. Jeltsch, F. & Wissel, C. 1994. Modelling dieback phenomena in natural forests. Ecol. Model. 75/76: 111-121.
20. Jeltsch, F., Milton, S.J., Dean, W.R.J. & van Rooyen, N. 1996. Tree spacing and coexistence in semi-arid savannas. J. Ecol. 84: 583-591.
21. Leistner, O.A. 1967. The plant ecology of the southern Kalahari. Mem. Bot. Surv. S. Afr. 38: 1-172.
22. Mace, R. 1991. Overgrazing overstated. Nature 349: 280-281.
23. Martens, H.E. 1971. The effect of tribal grazing patterns on the habitat in the Kalahari. Botswana Not. Rec. 1: 234-241.
24. Moore, A. 1988. Evapotranspiration in three plant communities of a Rhigozum trichotomum habitat at Upington. J. Grassl. Soc. S. Afr. 5: 80-84.
25. Moore, A. 1989. Die ecologie en ekofisiologie van Rhigozum trichotomum. Ph. D. Thesis, University of Port Elizabeth.
26. O'Connor, T.G. 1985. A synthesis of field experiments concerning the grass layer in the savanna regions of southern Africa. South African National Scientific Programmes Report No 114, Pretoria.
27. O'Connor, T.G. 1995. Acacia karroo invasion of grassland: environment and biotic effects influencing seedling emergence and establishment. Oecologia (Berl.) 103: 214-223.
28. Perkins, J.S. & Thomas, D.S.G. 1993a. Environmental responses and sensitivity to permanent cattle ranching, semi-arid western central Botswana. In: Thomas, D.S.G. & Allison, R.J. (eds.) Landscape sensitivity, pp. 273-286. Wiley, London.
29. Perkins, J.S. & Thomas. D.S.G. 1993b. Spreading deserts of spatially confined environmental impacts - land degradation and cattle ranching in the Kalahari desert of Botswana. Land Degrad. Rehahil. 4: 179-194.
30. Pickup, G. 1994. Modelling patterns of defoliation by grazing animals in rangelands. J. Appl. Ecol. 31: 231-246.
31. Queiroz, J.S 1993. Range degradation in Botswana: myth or reality? Overseas Dev. Netw. 35b: 1-17.
32. Richter, C.G.F. 1991. Gras-bosinteraksie in die bosveldgebiede van Noord-Kaap. Ph.D. Thesis, University of Bloemfontein.
33. Scholes, R.J. & Walker, B.H. 1993. An African savanna -synthesis of the Nylsvley study. Cambridge University Press, Cambridge.
34. Silvertown, J., Holtier, S., Johnson, J. & Dale, P. 1992. Cellular automaton models of interspecific competition for space - the effect of pattern on process. J. Ecol. 80: 527-534.
35. Skarpe, C. 1991. Impact of grazing in savanna ecosystems. Ambio 20: 351-356.
36. Skarpe, C. 1992. Dynamics of savanna ecosystems. J. Veg. Sci. 3: 293-300.
37. Talbot, W.J. 1961. Land utilization in the arid regions of southern Africa. Part I. South Africa. Arid Zone Research 17: 299-338.
38. Teague, W.R. & Smit, G.N. 1992. Relations between woody and herbaceous components and the effect of bush-clearing in southern African savannas. J. Grassl. Soc. S. Afr. 9: 60-71.
39. Thomas, D.S.G. & Shaw, P.A. 1991. The Kalahari environment. Cambridge Univ. Press, Cambridge.
40. Thrash, I., Theron, G.K. & Bothma, J. du P. 1995. Dry season herbivore densities around drinking troughs in the Kruger National Park. J. Arid Environ. 29: 213-220.
41. Tietema, T., Tolsma, D.J., Veenendaal, E.M. & Schroten, J. 1991. Plant responses to human activities in the tropical savanna ecosystem of Botswana. In: Rozema, J. & Verkleij, J.A.C. (eds.) Ecological response to environmental stresses, pp 262-276. Kluwer, Dordrecht.
42. Tolsma, D.J., Ernst, W.H.O. & Verwey, R.A. 1987. Nutrients in soil and vegelation around two artificial waterpoints in Eastern Botswana. J. Appl. Ecol. 24: 991-1000.
43. Trollope, W.S.W. 1982. Ecological effects of fire in South African savannas. In: Huntley, B.J. & Walker, B.H. (eds.) Ecology of tropical savannas, pp. 292-306. Ecol. Studies 42. Sprineer, Berlin.
44. van Rooyen, T.H. 1984. The soils of the Kalahari Gemsbok National Park. Koedoe 27: 45-61.
45. van Rooyen, N., Bezuidenhout, D., Theron, G.K. & Bothma, J. du P. 1990. Monitoring of the vegetation around artificial watering points (windmills) in the Kalahari Gemsbok National Park. Koedoe 33: 63-88.
46. van Rooven, N., Bredenkamp, G.J. & Theron, G.K. 1991a. Kalahari vegetation: veld condition trends and ecological status of species. Koedoe 34: 61-72.
47. van Rooyen, N., Theron, G.K. & Bredenkamp, G.J. 1991b. Long term vegetation dynamics in the semi-arid Kalahari. Koedoe 34: 91-92.
48. van Rooyen, N., Bredenkamp, G.J., Theron, G.K., Bothma, J. du P. & le Riche, E.A.N. 1994. Vegetational gradients around artificial watering points in the Kalahari Gemsbok National Park. J. Arid Environ. 26: 349-362.
49. Walker, B.H. & Noy-Meir, I. 1982. Aspects of stability and resilience of savanna ecosystems. In: Huntley, B.J. & Walker, B.H. (eds.) Ecology of tropical savannas, pp. 143-155. Ecological Studies 42. Springer, Berlin.
50. Whitmore, J.S. 1971. South Africa's water budget. South Afr. J. Sci. 67: 166-176.
51. Wiecand, T., Milton, S.J. & Wissel, C. 1995. A simulation model for a shrub-ecosystem in the semi-arid Karoo, South Africa. Ecology 76: 2205-2221.
52. Zucchini, W., Adamson, P. & McNeill, L. 1992. A model of Southern African rainfall. S. Afr. J. Sci. 88: 103-109.