Changes in population biology of two succulent shrubs along a grazing gradient

Journal of Applied Ecology

Volumn 40, Issue 4, 2003, Pages 615-625

  Riginos, Corinna ^a,c   Hoffman, M Timm ^b  

^a STELLENBOSCH UNIVERSITY   (South Africa)

^b UNIVERSITY OF CAPE TOWN   (South Africa)

^c UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

Communal rangeland; Establishment; Recruitment; Seed production; Seedling survival; Succulent Karoo

Indexed keywords

COMMON LAND; COMMUNITY COMPOSITION; GRAZING MANAGEMENT; GRAZING PRESSURE; MORTALITY; PLANT COMMUNITY; RANGELAND; RECRUITMENT; SEEDLING ESTABLISHMENT;

SOUTH AFRICA;

ANIMALIA; CHEIRIDOPSIS DENTICULATA; GALENIA AFRICANA; RUSCHIA ROBUSTA;

EID: 0041766736     PISSN: 00218901     EISSN: None     Source Type: Journal    
DOI: 10.1046/j.1365-2664.2003.00826.x     Document Type: Article

References (52)

1. Andrew, M.H. (1988) Grazing impact in relation to livestock watering points. Trends in Ecology and Evolution, 3, 336-339.
2. Andrew, M.H. & Lange, R.T. (1986) Development of a new piosphere in arid chenopod shrubland grazed by sheep. II. Changes to the vegetation. Australian Journal of Ecology, 11, 411-424.
3. Assaeed, A.M. & Al-Doss, A.A. (2001) Seedling competition of Lasiurus scindicus and Rhazya stricta in response to water stress. Journal of Arid Environments, 49, 315-320.
4. Bray, R.H. & Kurtz, L.T. (1945) Determination of total, organic, and available forms of phosphorus in soils. Soil Science, 59, 39-45.
5. Carrick, P.J. (2001) Shrub community dynamics in a South African semi-desert. PhD Thesis. Cambridge University, Cambridge, UK.
6. Combrinck, A. (2003) Grazing management in a semi-arid environment with GIS: Paulshoek as a case study. MSc Thesis. University of Stellenbosch, Stellenbosch, South Africa.
7. Cowling, R.M. & Hilton-Taylor, C. (1999) Plant biogeography, endemism and diversity. The Karoo: Ecological Patterns and Processes (eds W.R.J. Dean & S.J. Milton), pp. 42-56. Cambridge University Press, Cambridge, UK.
8. Cowling, R.M. & Pierce, S. (1999) Namaqualand: A Succulent Desert. Fernwood Press, Cape Town, South Africa.
9. Cowling, R.M., Esler, K.J. & Rundel, P.W. (1999) Namaqualand, South Africa - an overview of a unique winter-rainfall desert ecosystem. Plant Ecology, 142, 3-21.
10. Dean, W.R.J. (1992) Effects of animal activity on the absorption rate of soils in the southern Karoo, South Africa. Journal of the Grassland Society of South Africa, 9, 178-180.
11. Desmet, P.G. & Cowling, R.M. (1999) Biodiversity, habitat and range-size aspects of a flora from a winter rainfall desert in northwestern Namaqualand, South Africa. Plant Ecology, 142, 23-33.
12. Dregne, H.E. (1983) Desertification of Arid Lands. Harwood Academic Publishers, London, UK.
13. Esler, K.J. (1999) Plant reproductive ecology. The Karoo: Ecological Patterns and Processes (eds W.R.J. Dean & S.J. Milton), pp. 123-144. Cambridge University Press, Cambridge, UK.
14. Fenner, M. (1985) Seed Ecology. Chapman & Hall Ltd, London, UK.
15. Franco, A.C. & Nobel, P.S. (1989) Effect of nurse plants on the microhabitat and growth of cacti. Journal of Ecology, 77, 870-886.
16. Fusco, M., Holechek, J., Tembo, A., Daniel, A. & Cardenas, M. (1995) Grazing influences on watering point vegetation in the Chihuahuan desert. Journal of Range Management, 48, 32-38.
17. Hoffman, M.T., Cousins, B., Meyer, T., Petersen, A. & Hendricks, H. (1999) Historical and contemporary land use and the desertificafion of the Karoo. The Karoo: Ecological Patterns and Processes (eds W.R.J. Dean & S.J. Milton), pp. 257-273. Cambridge University Press, Cambridge, UK.
18. Hunt, L.P. (2001) Heterogeneous grazing causes local extinction of edible perennial shrubs: a matrix analysis. Journal of Applied Ecology, 38, 238-252.
19. James, C.D., Landsberg, J. & Morton, S.R. (1999) Provision of watering points in the Australian arid zone: a review of the effects on biota. Journal of Arid Environments, 41, 87-121.
20. Jeltsch, F., Milton, S.J., Dean, W.R.J. & van Rooyen, N. (1997) Simulated pattern formation around artificial waterholes in the semi-arid Kalahari. Journal of Vegetation Science, 8, 177-188.
21. Landsberg, J., James, C.D., Maconochie, J., Nicholls, A.O., Stol, J. & Tynan, R. (2002) Scale-related effects of grazing on native plant communities in an arid rangeland region of South Australia. Journal of Applied Ecology, 39, 427-444.
22. Lange, R.T., Coleman, D. & Cowley, K.R. (1992) Survival of saltbush (Atriplex vesicaria) seedlings in heavily grazed experimental plots. Australian Journal of Ecology, 17, 99-101.
23. McAuliffe, J.R. (1984) Sahuaro-nurse tree associations in the Sonoran Desert: competitive effects of sahuaros. Oecologia, 64, 319-321.
24. Middleton, N. & Thomas, D. (1997) World Atlas of Desertification, 2nd edn. United Nations Environment Programme. Arnold, London, UK.
25. Milton, S.J. (1994a) Growth, flowering, and recruitment of shrubs in grazed and in protected rangeland in the arid Karoo, South Africa. Vegetatio, 111, 17-27.
26. Milton, S.J. (1994b) Small-scale reseeding trials in arid rangeland: effects of rainfall, clearing, and grazing on seedling survival. African Journal of Range and Forage Science, 11, 54-58.
27. Milton, S.J. (1995) Spatial and temporal patterns in the emergence and survival of seedlings in arid Karoo shrubland. Journal of Applied Ecology, 32, 145-156.
28. Milton, S.J., Davies, R.A.G. & Kerley, G.I.H. (1999) Population level dynamics. The Karoo: Ecological Patterns and Processes (eds W.R.J. Dean & S.J. Milton), pp. 183-207. Cambridge University Press, Cambridge, UK.
29. Milton, S.J. & Dean, W.R.J. (1990) Seed production in rangelands of the southern Karoo. South African Journal of Science, 86, 231-233.
30. Milton, S.J. & Dean, W.R.J. (1995) South Africa's arid and semiarid rangelands: why are they changing and can they be restored? Environmental Monitoring and Assessment, 37, 245-264.
31. Milton, S.J., Gourlay, I.M. & Dean, W.R.J. (1997) Shrub growth and demography in arid Karoo, South Africa: inference from wood rings. Journal of Arid Environments, 37, 487-496.
32. Moleele, N.M. & Perkins, J.S. (1998) Encroaching woody plant species and boreholes: is cattle density the main driving factor in the Olifants Drift communal grazing lands, south-eastern Botswana? Journal of Arid Environments, 40, 245-253.
33. Morton, J.D. & Baird, D.B. (1990) Spatial distribution of dung patches under sheep grazing. New Zealand Journal of Agricultural Research, 33, 285-294.
34. Nelson, D.W. & Sommers, L.E. (1982) Total carbon, organic carbon and organic matter. Methods of Soil Analysis (ed. A.L. Page), pp. 570-571. American Society of Agronomy, Madison, MI, USA.
35. Oba, G., Vetaas, O.R. & Stenseth, N.C. (2001) Relationships between biomass and plant species richness in arid-zone grazing lands. Journal of Applied Ecology, 38, 836-846.
36. O'Connor, T.G. & Pickett, G.A. (1992) The influence of grazing on seed production and seed banks of some African grasslands. Journal of Applied Ecology, 29, 247-260.
37. Parolin, P. (2001) Seed expulsion in fruits of Mesembryanthemaceae: a mechanistic approach to study the effect of fruit morphological structures on seed dispersal. Flora, 196, 313-322.
38. Perkins, J.S. & Thomas, D.S.G. (1993) Spreading deserts or spatially confined environmental impacts - land degradation and cattle ranching in the Kalahari Desert, Botswana. Land Degradation and Rehabilitation, 4, 179-194.
39. Phillips, D.L. & MacMahon, J.A. (1981) Competition and spacing patterns in desert shrubs. Journal of Ecology, 69, 97-115.
40. Pickup, G. & Chewings, V.H. (1994) A grazing gradient approach to land degradation assessment in arid areas from remotely-sensed data. International Journal of Remote Sensing, 15, 597-617.
41. Rice, W.R. (1989) Analyzing tables of statistical tests. Evolution, 43, 223-225.
42. SAS (1994) JMP Users Guide, version 3.1. SAS Institute, Cary, North Carolina, USA.
43. Stokes, C.J. (1994) Degradation and dynamics of Succulent Karoo vegetation. MSc Thesis. University of Natal, Pietermaritzburg, South Africa.
44. Todd, S.W. (2000) Patterns of seed production and shrub association in two palatable Karoo shrub species under contrasting land use intensities. African Journal of Range and Forage Science, 17, 22-26.
45. Todd, S.W. & Hoffman, M.T. (1999) A fence-line contrast reveals effects of heavy grazing on plant diversity and community Composition in Namaqualand, South Africa. Plant Ecology, 142, 169-178.
46. Tolsma, D.J., Ernst, W.H.O. & Verwey, R.A. (1987) Nutrients in soil and vegetation around two artificial waterpoints in eastern Botswana. Journal of Applied Ecology, 24, 991-1000.
47. Turner, M.D. (1998a) Long-term effects of daily grazing orbits on nutrient availability in Sahelian West Africa. I. Gradients in the chemical composition of rangeland soils and vegetation. Journal of Biogeography, 25, 669-682.
48. Turner, M.D. (1998b) Long-term effects of daily grazing orbits on nutrient availability in Sahelian West Africa. II. Effects of a phosphorus gradient on spatial patterns of annual grassland production. Journal of Biogeography, 25, 683-694.
49. Turner, R.M., Alcorn, S.M. & Olin, G. (1969) Mortality of transplanted Saguaro seedlings. Ecology, 50, 835-844.
50. 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. Journal of Arid Environments, 26, 349-362.
51. Watson, I.W., Westoby, M. & Holm, A.McR. (1997) Demography of two shrub species from an arid grazed ecosystem in western Australia 1983-93. Journal of Ecology, 85, 815-832.
52. Yeaton, R.I. & Esler, K.J. (1990) The dynamics of a Succulent Karoo vegetation. Vegetatio, 88, 103-113.