Modelling the impact of small-scale heterogeneities on tree-grass coexistence in semi-arid savannas

Journal of Ecology

Volumn 86, Issue 5, 1998, Pages 780-793

  Jeltsch, F ^a   Milton, S J ^b   Dean, W R J ^b   Van Rooyen, N ^c   Moloney, K A ^d  

^a HELMHOLTZ CENTRE FOR ENVIRONMENTAL RESEARCH UFZ   (Germany)

^b UNIVERSITY OF CAPE TOWN   (South Africa)

^c UNIVERSITY OF PRETORIA   (South Africa)

^d 353 Bessey Hall ^*  (United States)

Author keywords

Coexistence; Grid based simulation model; Kalahari; Savanna; Seed clumping; Spatial vegetation dynamics; Stability; Tree spacing

Indexed keywords

CLUSTER ANALYSIS; GENETIC CORRELATION; GENETIC HETEROGENEITY; GRASS; PLANT GENETICS; PLANT MODEL; POPULATION GENETICS; RODENT; SAVANNA; SEED; SIMULATION MODEL; TREE;

COEXISTENCE; GRASS; HETEROGENEITY; SAVANNA; TREE; VEGETATION STRUCTURE;

EID: 0031732360     PISSN: 00220477     EISSN: None     Source Type: Journal    
DOI: 10.1046/j.1365-2745.1998.8650780.x     Document Type: Article

References (43)

1. Belsky, A.J. (1994) Influences of trees on savanna productivity: tests of shade, nutrients, and tree-grass competition. Ecology, 75, 922-932.
2. Belsky, A.J., Mongwa, S.M., Amundson, R.G., Duxbury, J.M. & Ali, A.R. (1993) Comparative effects of isolated trees on their undercanopy environments in high and low rainfall savannas. Journal of Applied Ecology, 30, 143-155.
3. Bews, J.W. (1917) The plant succession in the thorn veld. South African Association for the Advancement of Science, 7, 121.
4. Bothma, J., du, P., van Rooyen, N., Theron, G.K. & le Riche, E.A.N. (1994) Quantifying woody plants as hunting cover for southern Kalahari leopards. Journal of Arid Environments, 26, 273-280.
5. Burtt, B.D. (1929) A record of fruits and seeds dispersed by mammals and birds from the singida district of Tanganyika territory. Journal of Ecology, 17, 351-355.
6. Chew, R.M. & Whitford, W.G. (1992) A long-term positive effect of kangaroo rats (Diplodomys spectabilis) on creosote bushes (Larrea tridentata). Journal of Arid Environments, 22, 375-386.
7. Davis, M.A., Wrage, K.J. & Reich, P.B. (in press) Competition between tree seedlings and herbaceous vegetation: support for a resource supply and demand theory. Journal of Ecology
8. Dean, W.R.J. & Milton, S.J. (1991) Patch disturbances in arid grassy dunes: antelope, rodents and annual plants. Journal of Arid Environments, 20, 231-237.
9. DeAngelis, D.L. & Gross, L.A. (1992) Individual-Based Models and Approaches in Ecology. Chapman and Hall, New York.
10. Eagleson, P.S. & Segarra, R.I. (1985) Water-limited equilibrium of savanna vegetation systems. Water Resources Research, 21, 1483-1493.
11. Fragosa, J.M.V. (1997) Tapir-generated seed shadows: scale-dependent patchiness in the Amazon rain forest. Journal of Ecology, 85, 519-529.
12. Frost, P.G.H. & Robertson, F. (1987) The ecological effect of fire in savannas. Determinants of Tropical Savannahs (ed. B.H. Walker), pp. 93-140. ICSU Press, Miami.
13. Grubb, P.J. (1977) The maintenance of species richness in plant communities. The importance of the regeneration niche. Biological Reviews of the Cambridge Philosophical Society, 52, 107-145.
14. Hansell, M.H. (1993) The ecological impact of animal nests and burrows. Functional Ecology, 7, 5-12.
15. Hochberg, M.E., Menault, J.C. & Gignoux, J. (1994) The influences of tree biology and fire in the spatial structure of the West African savanna. Journal of Ecology, 82, 217-226.
16. Huston, M.A. (1979) A general hypothesis of species diversity. American Naturalist, 113, 81-101.
17. Jeltsch, F., Milton, S.J., Dean, W.R.J. & van Rooyen, N. (1996) Tree spacing and coexistence in semi-arid savannas. Journal of Ecology, 84, 583-595.
18. Jeltsch, F., Milton, S.J., Dean, W.R.J. & van Rooyen, N. (1997a) Simulating pattern formation around artificial waterholes in the semi-arid Kalahari. Journal of Vegetation Science, 8, 177-189.
19. Jeltsch, F., Milton, S.J., Dean, W.R.J. & van Rooyen, N. (1997b) Analyzing shrub encroachment in the southern Kalahari: a grid-based modelling approach. Journal of Applied Ecology, 34, 1497-1509.
20. Leistner, O.A. (1961) On the dispersal of Acacia giraffae by game. Koedoe, 4, 101-104.
21. Leistner, O.A. (1967) The plant ecology of the southern Kalahari. Memoirs of the Botanical Society of South Africa, 38, 11-73.
22. Leistner, O.A. & Werger, M.J.A. (1973) Southern Kalahari phytosociology. Vegetatio, 28, 353-399.
23. Lovegrove, B.G. & Painting, S. (1987) Variations in the foraging behaviour and burrow structures of the Damara molerat Cryptomys damarensis in the Kalahari Gemsbok National Park. Koedoe, 30, 149-162.
24. McConnaughay, K. & Bazzaz, F. (1991) Is physical space a soil resource? Ecology, 72, 94-103.
25. McNaughton, S.J. (1992) The propagation of disturbance in savannas through food webs. Journal of Vegetation Science, 3, 301-314.
26. Milton, S.J. & Dean, W.R.J. (1995) How useful is the keystone species concept, and can it be applied to Acacia erioloba in the Kalahari desert? Zeitschrift für Ökologie und Naturschutz, 4, 147-156.
27. Moloney, K.A. & Levin, S.A. (1996) The effects of disturbance architecture on landscape-level population dynamics. Ecology, 77, 375-394.
28. Nel, J.A.J. (1978) Habitat heterogeneity and changes in small mammal community structure and resource utilization in the southern Kalahari. Bulletin of the Carnegie Museum of the National History, 6, 118-132.
29. Nel, J.A.J. (1990) Foraging and feeding by bat-eared foxes Otocyon megalotis in the southwestern Kalahari. Koedoe, 33, 9-16.
30. Nel, J.A.J. & Rautenbach, I.L. (1975) Habitat use and community structure of rodents in the southern Kalahari. Mammalia, 39, 9-29.
31. Nel, J.A.J., Rautenbach, I.L., Els, D.A. & De Graaf, G. (1984) The rodents and other small mammals of the Kalahari Gemsbok National Park. Koedoe (Suppl.), 195-220.
32. Rebertus, A.J. & Burns, B.R. (1997) The importance of gap processes in the development and maintenance of oak savannas and dry forests. Journal of Ecology, 85, 635-645.
33. Sarmiento, G. (1984) The Ecology of Neotropical Savannas. Harvard University Press, London.
34. Scholes, R.J. & Walker, B.H. (1993) An African Savanna -Synthesis of the Nylsvley Study. Cambridge University Press, Cambridge.
35. Skarpe, C. (1990) Structure of the woody vegetation in disturbed and undisturbed arid savanna, Botswana. Vegetatio, 87, 11-18.
36. Skarpe, C. (1992) Dynamics of savanna ecosystems. Journal of Vegetation Science, 3, 293-300.
37. Smithers, R.H.N. (1983) The Mammals of the Southern African Subregion. University of Pretoria, Pretoria, South Africa.
38. Trollope, W.S.W. (1982) Ecological effects of fire in South African savannas. Ecology of Tropical Savannas (eds B.J. Huntley & B.H. Walker), pp. 292-306. Ecological Studies 42. Springer, New York.
39. 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.
40. Walker, B.H. & Noy-Meir, I. (1982) Aspects of stability and resilience of savanna ecosystems. Ecology of Tropical Savannas (eds B.J. Huntley & B.H. Walker), pp. 143-155. Ecological Studies 42. Springer, Berlin.
41. Walker, B.H., Ludwig, D., Holling, C.S. & Peterman, R.M. (1981) Stability of semi-arid savanna grazing systems. Journal of Ecology, 69, 473-498.
42. Ward, J.D. & Breen, C.M. (1983) Drought stress and the demise of Acacia albida along the Lower Kuiseb River, central Namib Desert: preliminary findings. South African Journal of Science, 79, 444-447.
43. Yeaton, R.I. (1988) Porcupines, fires and the dynamics of the tree layer of the Burkea africana savanna. Journal of Ecology, 76, 1017-1029.