Plant Ecology

, Volume 176, Issue 1, pp 19–33 | Cite as

Plant species richness and composition a long livestock grazing intensity gradients in a Namaqualand (South Africa) protected area

  • H. H. Hendricks
  • W. J. Bond
  • J. J. Midgley
  • P. A. Novellie
Article
Received:
Accepted:

Abstract

The study described changes in floristic and vegetation structure in relation to livestock grazing intensity in a conservation area in the Succulent Karoo, South Africa. Grazing by goats and sheep is allowed in the Richtersveld National Park (a contractual National Park. which is also an area of high floristic richness and endemism. We used goat faecal pellet density, degree of trampling and percentage bare-ground at distances from the stock posts as surrogates for a gradient in grazing pressure. A stock post is the place where farmers keep, in most cases in an enclosure called a ‘kraal’, their animals at night and to which they return every evening after the day’s herding. Twenty-seven stock posts were located in the Richtersveld National Park; nine stock posts on flats, foot– slopes and mountain each. We measured plant species richness and diversity, and mean percentage cover of the various plant growth forms (including the number of species falling into each growth form category. in each of the five 10 m . 10 m plots (each 200 m apart. demarcated along a transect of one kilometre length from the centre of each stock post. The results showed that distance from the stock post does reflect grazing intensity use because densities in faecal pellets rapidly declined with increasing distances away from the stock post for all habitats studied. Faecal density was positively correlated with stocking density. Plant species richness and diversity was at a minimum near stock posts. Plants able to endure the effects of heavy grazing occurred near stock posts where declines in palatable plant species, assumingly sensitive to heavy grazing and trampling, were recorded. Grazing increased vegetation patchiness up to 800 m from the stock post for all the habitats. The degree to which this change in species composition occurred did not depend on stocking densities, suggesting that both grazing and landscape variability were responsible for vegetation changes in rangelands of that area of the Succulent Karoo biome.

Keywords

Grazing impacts Growth form Herbivory Stock post Succulent Karoo 
This is a preview of subscription content, log in to check access.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Barnes, D.L. 1976A review of plant–based methods for estimating food consumption, percentage utilization, species preferences and feeding patterns of grazing and browsing animalsProceedings of the Grassland Society of Southern Africa116571Google Scholar
  2. Bastin, G.N., Pickup, G., Chewings, V.H., Pearce, G. 1993aLand degradation assessment in central Australia using a grazing gradient methodRangeland Journal15190216Google Scholar
  3. Bastin, G.N., Sparrow, A.D., Pearce, G. 1993bGrazing gradients in central Australian rangelands: ground verification of remote sensing–based approachRangeland Journal.15217233Google Scholar
  4. Bond, W.J. 1999Rangelands and biodiversity in southern Africa – impacts of contrasting management systems.. In: Eldridge DFreundenberger, D. eds. People and Rangelands: buiding the future. Proceedings of the VI International Rangeland CongressQueenslandAustraliaGoogle Scholar
  5. Bond, W.J., Ladd, P.G. 2001Dynamics of the overstorey and species richness in Australian heathlandsJournal of Mediterranean Ecology2247257Google Scholar
  6. Bromilow, C. 1995Problem plants of South AfricaBriza PublicationsPretoria, South AfricaGoogle Scholar
  7. Collins, S.L. 1992Heterogeneity of disturbed tallgrass prairie communitiesEcology7320012006Google Scholar
  8. Coupland, R.T. 1992Mixed prairie: ecosystems of the worldCoupland, R.T. eds. Natural grasslands: introduction and Western HemisphereElsevierNew York, USA151182Google Scholar
  9. Cowling, R.M., Esler, K.J., Rundel, P.W. 1999Namaqualand, South Africa –an overview of a unique winter–rainfall desert ecosystemPlant Ecology142321CrossRefGoogle Scholar
  10. Cowling, R.M., Gibbs Russel, G.E., Hoffman, M.T., Hilton–Tay–lor, C. 1989Patterns of plant species diversity in southern Africa.. In: Huntley BHuntley, B.J. eds. Biotic diversity in Southern AfricaOxford University PressCape Town, South Africa1950Google Scholar
  11. Cowling, R.M., Hilton–Taylor, C. 1994Patterns of plant diversity and endemism in southern Africa: an overviewStrelitzia13152Google Scholar
  12. Cowling, R.M., Pierce, S.M. 1999Namaqualand: a succulent desertFernwood PressVlaeberg, South AfricaGoogle Scholar
  13. Ellis, W.A.H., Sullivan, B.J., Lisle, A.T., Carrick, F.N. 1998Spatial and temporal distribution of koala faecal pelletsWildlife Research.25663668CrossRefGoogle Scholar
  14. Esler, K.J., Rundel, P.W. 1999Comparative patterns of phenology and growth from diversity in two winter rainfall deserts: the Succulent Karoo and Mojave Desert ecosystemsPlant Ecology14297104CrossRefGoogle Scholar
  15. Esler, K.J., Rundel, P.W., Cowling, R.M. 1999The Succulent Karoo in a global context: plant structural and functional comparison with North American winter rainfall desertsDean, W.R.J.Milton, S.J. eds. The Karoo: Ecological patterns and processesCambridge University PressUnited Kingdom257273Google Scholar
  16. Foran, B.D., Bastin, G.N., Shaw, K.A. 1986Range assessment and monitoring in arid lands: the use of classification and ordination in range surveyJournal of Environmental Management226784Google Scholar
  17. Graetz, R.D., Ludwig, J.A. 1978A method for the analysis of piophere data applicable to range assessmentAustralian Rangeland Journal.1126136Google Scholar
  18. Hendricks, H.H. 1998Traditional stock farming in the RichtersveldVeld and Flora848687Google Scholar
  19. Hendricks, H.H., Novellie, P.A., Midgley, J.J. 2002Diet selection of goats in the Richtersveld National ParkAfrican Journal of Range and Forage Science.19111Google Scholar
  20. Hendricks H.H., Bond W.J., Migley J.J. and Novellie P.A. 2003. On the move – mitigating the effect of rainfall variability on livestock production. African Journal of Range and Forage Science (submitted).Google Scholar
  21. Hilton–Taylor, C. 1996Patterns and characteristics of the flora of the Succulent Karoo Biome, southern AfricaMaesen, L.J.E.Burgt, X.M.Medenbachde Rooy, J.M. eds. The biodiversity of African plantsKluwer Academic PublishersDordrecht, The Netherlands5872Google Scholar
  22. Hoffman, M.T. 1989A preliminary investigation of the phenology of subtropical thicket and karroid shrublands in the lower Sundays River Valley, SE CapeSouth African Journal of Botany55586597Google Scholar
  23. Hoffman, MT, Cousins, B, Meyer, T, Petersen, A, Hendricks, HH. 1999Historical and contemporary land use and the desertification of the karooDean, W.R.J.Milton, S.J. eds. The Karoo: Ecological patterns and processesCambridge University PressUnited Kingdom257273Google Scholar
  24. Huntley, B.J. 1989Biotic diversity in Southern AfricaOxford University PressCape Town, South AfricaGoogle Scholar
  25. James, C., Stafford Smith, M., Bosma, J., Landsberg, J., Tynan, R., Maconochie, J. 1999Production, persistence, economic and extinction: integrating conservation and pastoralism in Australian rangelands.. In: Eldridge FFreudenberger, D. eds. People and Rangelands: building the futureProceedings of the VI International Rangeland CongressQueensland, AustraliaGoogle Scholar
  26. Jürgens, N., Gotzmann, I.H., Cowling, R.M. 1999Remarkable medium–term dynamics of leaf succulent Mesembryanthemaceae shrubs in the winter–rainfall desert of northwestern Namaqualand, South AfricaPlant Ecology.1428796CrossRefGoogle Scholar
  27. Land Type Survey Staff1987Land types of the maps Alexander Bay 2816, 2818 Warmbad, 2916 Springbok, 2918 Pofadder, 3017 Garies, 3018 LoeriefonteinMemoir of Agriculture and Natural Resource of South AfricaPretoria, South AfricaNo. 9.Google Scholar
  28. Lange, R.T. 1969The piosphere: sheep track and dung patternsJournal of Range Management22396400Google Scholar
  29. Landsberg, J., James, C.D., Morton, S., Hobbs, T.J., Stol, J., Drew, A., Tongway, H. 1997The effects of artificial sources of water on rangeland biodiversity. Final report to the Biodiversity Convention and Strategy Section of the Biodiversity Group, Environment AustraliaCSIROCanberraGoogle Scholar
  30. Milchunas, D.G., Lauenroth, W.K. 1993Quantitative effects of grazing on vegetation and soils over a global range of environmentsEcological Monographs.63327366Google Scholar
  31. Milton, S.J. 1991Plant spinescence in arid southern Africa: does moisture mediate selection by mammals?Oecologia87279287CrossRefGoogle Scholar
  32. Milton, S.J., Dean, W.R.J., Settele, J., Vetterlein, D. 1998Effects of physical refuges and human activities on plant population dynamics and bird assemblages in the Richtersveld National Park Pp8. Unpublished technical report, Scientific ServicesSouth African National ParksKimberleyGoogle Scholar
  33. Milton, S.J., Hoffman, M.T. 1994The application of state–and–transition models to arid rangeland research and management in arid succulent and semi–arid grassy Karoo, South AfricaAfrican Journal of Range and Forage Science111826Google Scholar
  34. Milton, S.J., Yeaton, R.I., Dean, W.R.J., Vlok, J.H.J. 1997Succulent KarooppCowling, R.M.Richardson, D.M.Pierce, S.M. eds. The vegetation of Southern AfricaCambridge University PressCambridge, UK131166Google Scholar
  35. O’Connor, T.G., Roux, P.W. 1995Vegetation changes (1949–71. in a semi–arid, grassy dwarf shrubland in the Karoo, South Africa: influence of rainfall variability and grazing by sheepJournal of Applied Ecology32612626Google Scholar
  36. Oskanen, J. 1996Is the hump relationship between species richness and biomass an artifact due to plot size?Journal of Ecology84293295Google Scholar
  37. Owen–Smith, N. 1999The animal factor in veld managementTainton, N.M. eds. Veld management in South Africa (ed N.M..) Second editionUniversity of Natal PressPietermaritzburg South Africa117138Google Scholar
  38. Peet, R.K. 1974The measurement of species diversityAnnual Review of Ecology and Systematics.5285307CrossRefGoogle Scholar
  39. Pickup, G. 1989New land degradation survey techniques for arid Australia: problems and prospectsAustralian Rangeland Journa.117482Google Scholar
  40. Ritchie, M.E., Olff, H. 1999Herbivore diversity and plant dynamics: compensatory and additive effectsOlff, H.Brown, V.K.Drent, R.T. eds. Herbivores: between plants and predatorsBlackwell ScienceLondon, UK175204Google Scholar
  41. Rossa, B., Willert, D.J. 1999Physiological characteristics of geophytes in semiarid Namaqualand, South AfricaPlant Ecology142121132CrossRefGoogle Scholar
  42. Roux, P.W., Vorster, M. 1983Vegetation change in the KarooProceedings of the Grassland Society of Southern Africa181824Google Scholar
  43. Rutherford, M.C., Westfall, R.M. 1986Biomes of southern Africa – an objective categorizationMemoirs of the Botanical Survey of South Africa54198Google Scholar
  44. Schwilk, D.W., Keeley, J.E., Bond, W.J. 1997The intermediate disturbance hypothesis does not explain fire and diversity patterns in fynbosPlant Ecology1327784CrossRefGoogle Scholar
  45. Stevens, MHH, Carson, WP 1999Plant density determines species richness along an experimental fertility gradientEcology80455465Google Scholar
  46. Stokes C.J. 1994. Degradation and dynamics of Succulent Karoo vegetation. MSc. thesis. University of Natal, South Africa.Google Scholar
  47. Swift, L.W. 1976Algorithm for solar radiation on mountain slopesWater Resources Research.12108112Google Scholar
  48. Tainton, N.M. 1981The ecology of the main grazing lands of South Africa: production characteristics of the main grazing landsTainton, N. eds. Veld and Pasture Management in South AfricaShuter and Shooter in association with Natal University PressPietermaritzburg, South Africa2556Google Scholar
  49. Tainton, N.M. 1999The ecology of the main grazing lands of South Africatainton, N.M. eds. Veld management in South Africa. Second editionUniversity of Natal PressPietermaritzburg, South Africa2353Google Scholar
  50. Todd, S., Hoffman, M.T. 1999Effects of heavy grazing on plant species diversity and community composition in a communally managed semi–arid shrubland, Namaqualand, South AfricaPlant Ecology142169178CrossRefGoogle Scholar
  51. Tynan, R., Maconochie, J., James, C., Landsberg, J., Tongway, D. 1999Grazing gradients, biodiversity and landscape function in Australian rangelandsEldridge, D.Freudenberger, D. eds. People and Rangelands: building the futureProceedings of the VI International Rangeland CongressQueensland, AustraliaGoogle Scholar
  52. Vander Heyden, F., Stock, W.D. 1999The response of forage plants to defoliation: karoo shrubsTainton, N.M. eds. Veld management in South Africa. Second editionUniversity of Natal PressPietermaritzburg South Africa103109Google Scholar
  53. Rooyen, N., Rensburg, D.J., Theron, G.K., Bothma Du, P. 1990Monitoring of the vegetation around artificial watering points (windmills) in the Kalahari Gemsbok National ParkKoedoe336388Google Scholar
  54. Willert, D.J., Eller, B.M., Werger, M.J.A., Brinckmann, E., Ihenfeldt, H.–D. 1992Life strategies of succulents in deserts: with special reference to the Namib DesertCambridge University PressCambridge UKGoogle Scholar
  55. Werger, M.J.A., Ellis, R.P. 1981Photosynthetic pathways in the arid regions of South AfricaFlora1716475Google Scholar
  56. Westoby, M. 1980Elements of a theory of vegetation dynamics in arid rangelandsIsrael Journal of Botany28169194Google Scholar
  57. Whittaker, R.H. 1980Classification of plant communitiesDr W. Junk bv PublishersThe Hague, London, UK.Google Scholar
  58. Wiegand, T., Milton, S.J. 1996Vegetation change in semi–arid communitiesVegetatio125169183CrossRefGoogle Scholar
  59. Wilson, A.D. 1986The monitoring of changes in range condition: a multivariate site potential approachIn: Rangelands: a resource under siegeProceedings of the IX International Rangeland Congress, Australian Academy of ScienceCanberra, Australia517521Google Scholar
  60. Yeaton, RI, Esler, KJ. 1990The dynamics of succulent karoo vegetation:a study of species association and recruitmentVegetatio88103113CrossRefGoogle Scholar
  61. Zar, J.H. 1984Biostatistical AnalysisPrentice–Hall. New JerseyUSAGoogle Scholar

Copyright information

© Springer 2005

Authors and Affiliations

  • H. H. Hendricks
    • 1
  • W. J. Bond
    • 2
  • J. J. Midgley
    • 2
  • P. A. Novellie
    • 3
  1. 1.South African National ParksHadison ParkSouth Africa
  2. 2.Botany DepartmentUniversity of Cape TownRondeboschSouth Africa
  3. 3.South African National ParksPretoriaSouth Africa

Personalised recommendations