Abstract
In arid regions, the effects of grazing management on natural communities of long-lived plants generally take years or even decades to become evident. Event-driven dynamic behaviour, disturbances, unpredictable and low rainfall and complex interactions between species make it difficult to gather sufficient understanding of vegetation dynamics for developing guidelines for sustainable management of arid rangelands. This is further complicated by the importance of spatial scales and patterns, e.g. patchiness of rainfall, heterogeneous grazing behaviour of domestic livestock or distances between artificial watering points.
Simulation models that consider the essential processes determining vegetation dynamics offer scope for quantitatively exploring long-term vegetation dynamics of arid rangelands. If these models are spatially explicit, they additionally allow for the investigation of spatial processes, such as competition or dispersal, and patterns such as landscape features or structures imposed by management (boreholes, paddocks etc.).
This chapter, discusses the promises and limitations of spatially explicit simulation models as (often neglected) tools for rangeland management. We focus on model examples from rangelands in southern Africa, namely a set of models simulating cattle grazing in the southern Kalahari and a model simulating a karakul sheep farm at the border of the Namib desert (Namibia).
Results of the Kalahari models show the existence of a grazing threshold that determines the long-term sustainability of livestock grazing. This threshold depends on rainfall, grazing intensity and grazing heterogeneity. Its effect is illustrated with the spatial vegetation dynamics around artificial watering points. The model of the karakul sheep farm is used to investigate a successful example of sustainable rangeland management under harsh conditions.
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References
Andrew MH (1988) Grazing impact in relation to livestock watering points. Trends Ecol Evol 3: 336–339
Archer S, Smeins FE (1991) Ecosystem-level processes. In: Heitschmidt RK, Stuth JW (eds) Grazing management. Timber, Oregon, pp 109–139
Dean WRJ, Macdonald IAW (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
Fourie JH, van Niekerk JW, Fouché HJ (1985) Weidingskapasiteitsnorme in die Vrystaatstreek. Glen Agric 14: 4–7
Friedel MH (1991) Range condition assessment and the concepts of thresholds: view point. J Range Manage 44: 422–426
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
Hellden U (1991) Desertification: time for an assessment? Ambio 20:372–383
Jeltsch F, Milton S, Dean WRJ, van Rooyen N (1996) Tree spacing and coexistence in semi-arid savannas. J Ecol 84: 583–595
Jeltsch F, Milton S, Dean WRJ, van Rooyen N (1997a) Simulated pattern formation around artificial waterholes in the semi-arid Kalahari. J Veg Sci 8: 177–189
Jeltsch F, Milton S, Dean WRJ, van Rooyen N (1997b) Analysing shrub encroachment in the southern Kalahari: a grid-based modelling approach. J Appl Ecol 34: 1497–1509
Jeltsch F, Milton SJ, Dean WRJ, Moloney K (1998) Modelling the impact of small-scale heterogeneities on tree-grass coexistence in semi-arid savannas. J Ecol 86: 780–794
Jeltsch F, Milton SJ, Moloney K (1999) Detecting process from snap-shot pattern-lessons from tree spacing in the southern Kalahari. OIKOS 85: 451–467
Kruger AS, Woehl H (1996) The challenge for Namibia’s future: sustainable land use under arid conditions. Entwicklung Ländlicher Raum 4: 16–20
Leistner OA (1967) The plant ecology of the southern Kalahari. Mem Bot Sury South Africa 38: 1–172
Martens HE (1971) The effect of tribal grazing patterns on the habitat in the Kalahari. Botswana Notes Rec 1: 234–241
Perkins JS, Thomas DSG (1993) Environmental responses and sensitivity to permanent cattle ranching, semi-arid western central Botswana. In: Thomas DSG, Allison RI (eds) Landscape sensitivity. Wiley, London, pp 273–286
Pickup G (1994) Modelling patterns of defoliation by grazing animals in rangelands. J Appl Ecol 31: 231–246
Pieri C, Steiner KG (1996) The role of soil fertility in sustainable agriculture with special reference to Sub—Saharan Africa. Entwicklung Ländlicher Raum 4: 3–6
Schlesinger WH, Reynolds JF, Cunningham GL, Huenneke LF, Jarrell WM, Virginia RA, Whitford WG (1990) Biological feedbacks in global desertification. Science 247: 1043–1048
Skarpe C (1990) Structure of the woody vegetation in disturbed and undisturbed arid savanna, Botswana. Vegetatio 87: 11–18
Skarpe C (1991) Impact of grazing in savanna ecosystems. Ambio 20: 351–356
Stephan T, Jeltsch F, Wiegand T, Wissel C, Breiting HA (1998) Sustainable farming at the edge of the Namib: analysis of land use strategies by a computer simulation model. In: Use, JL, Brebbia CA, Power H (eds) Ecosystems and sustainable development. Advances in ecological sciences 1. Computational Mechanics Publication, Southampton, pp 41–51
Thiéry JM, D’Herbés JM, Valentin C (1995) A model simulating the genesis of banded vegetation patterns in Niger. J Ecol 83: 497–507
Thomas DSG, Shaw PA (1991) The Kalahari environment. Cambridge Univ Press, Cambridge
Tolsma DJ, Ernst WHO, Verwey RA (1987) Nutrients in soil and vegetation around two artificial waterpoints in Eastern Botswana. J Appl Ecol 24: 991–1000
Walker BH (1993) Rangeland ecology: understanding and managing change. Ambio 22: 80–87
Walter H (1954) Die Grundlagen der Weidewirtschaft in Südwestafrika. Ulmer, Stuttgart
Weber GE, Jeltsch F (1998) Spatial aspects of grazing in savanna rangelands — a modelling study of vegetation dynamics. In: Usó JL, Brebbia CA, Power H (eds) Ecosystems and sustainable development. Advances in ecological sciences 1. Computational Mechanics Publication, Southampton, pp 427–437
Weber GE, Jeltsch F, van Rooyen N, Milton SJ (1998) Simulated long-term vegetation response to spatial grazing heterogeneity in semi-arid rangelands. J Appl Ecol 35: 687–699
Westoby M, Walker BH, Noy-Meir I (1989) Opportunistic management for rangelands not at equilibrium. J Range Manage 42: 266–274
Wiegand T, Milton SJ, Wissel C (1995) A simulation model for a shrub-ecosystem in the semi-arid Karoo, South Africa. Ecology 76: 2205–2221
Zucchini W, Adamson P, McNeill L (1992) A model of Southern African rainfall. South Afr J Sci 88: 103–109
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Jeltsch, F., Stephan, T., Wiegand, T., Weber, G.E. (2001). Arid Rangeland Management Supported by Dynamic Spatially Explicit Simulation Models. In: Breckle, SW., Veste, M., Wucherer, W. (eds) Sustainable Land Use in Deserts. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-59560-8_23
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DOI: https://doi.org/10.1007/978-3-642-59560-8_23
Publisher Name: Springer, Berlin, Heidelberg
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