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The utilization of large savanna trees by elephant in southern Kruger National Park

Published online by Cambridge University Press:  01 May 2008

Graeme Shannon*
Affiliation:
Amarula Elephant Research Programme, School of Biological and Conservation Sciences, Westville Campus, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa
Dave J. Druce
Affiliation:
Amarula Elephant Research Programme, School of Biological and Conservation Sciences, Westville Campus, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa
Bruce R. Page
Affiliation:
Amarula Elephant Research Programme, School of Biological and Conservation Sciences, Westville Campus, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa
Holger C. Eckhardt
Affiliation:
Scientific Services, Kruger National Park, Box 106, Skukuza, 1350, South Africa
Rina Grant
Affiliation:
Scientific Services, Kruger National Park, Box 106, Skukuza, 1350, South Africa
Rob Slotow
Affiliation:
Amarula Elephant Research Programme, School of Biological and Conservation Sciences, Westville Campus, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa
*
1Corresponding author. Email: graemeshannon@lycos.co.uk

Abstract:

Elephant are believed to be one of the main ecological drivers in the conversion of savanna woodlands to grassland. We assessed the impacts of elephant on large trees (≥5 m in height) in the southern section of the Kruger National Park. Tree dimensions and utilization by elephant were recorded for 3082 individual trees across 22 transects (average length of 3 km and 10 m wide). Sixty per cent of the trees exhibited elephant utilization and 4% were dead as a direct result of elephant foraging behaviour. Each height class of tree was utilized in proportion to abundance. However, the size of the tree and the species influenced the intensity of utilization and foraging approach. Sclerocarya birrea was actively selected for and experienced the highest proportional utilization (75% of all trees). Interestingly, the proportion of large trees that were utilized and pushed over increased with distance from permanent water, a result which has implications for the provision of water in the KNP. We conclude that mortality is likely to be driven by a combination of factors including fire, drought and disease, rather than the actions of elephant alone. Further investigation is also required regarding the role of senescence and episodic mortality.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2008

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References

LITERATURE CITED

BAXTER, P. W. J. & GETZ, W. M. 2005. A model-framed evaluation of elephant effects on tree and fire dynamics in African savannas. Ecological Applications 15:13311341.CrossRefGoogle Scholar
BEGON, M., HARPER, J. L. & TOWNSEND, C. R. 1996. Ecology: individuals, populations and communities. (Third edition). Blackwell Sciences, Oxford. 738 pp.CrossRefGoogle Scholar
BELSKY, A. J. 1994. Influences of trees on savanna productivity: tests of shade, nutrients and tree-grass competition. Ecology 75:922932.CrossRefGoogle Scholar
BUECHNER, H. K. & DAWKINS, H. C. 1961. Vegetation change induced by elephants and fire in Murchison Falls National Park, Uganda. Ecology 42:752766.CrossRefGoogle Scholar
CHAMAILLÉ-JAMMES, S., VALEIX, M. & FRITZ, H. 2007. Managing heterogeneity in elephant distribution: interactions between elephant population density and surface water-availability. Journal of Applied Ecology 44:625633.CrossRefGoogle Scholar
COCHRANE, E. P. 2003. The need to be eaten: Balanites wilsoniana with and without seed dispersal. Journal of Tropical Ecology 19:579589.CrossRefGoogle Scholar
COATES PALGRAVE, K. 2003. Trees of Southern Africa. (Third edition). Struik, Cape Town. 1000 pp.Google Scholar
CUMMING, D. H., FENTON, M. B., RAUTENBAUCH, I. L., TAYLOR, R. D., CUMMING, G. S., CUMMING, M. S., DUNLOP, J. M., FORD, A. G., HOVORKA, M. D., JOHNSTON, D. S., KALCOUNIS, M., MAHLANGU, Z. & PORTFORS, V. R. 1997. Elephants, woodlands and biodiversity in southern Africa. South African Journal of Science 93:231236.Google Scholar
DEAN, W. R. J., MILTON, S. J. & JELTSCH, F. 1999. Large trees, fertile islands, and birds in arid savanna. Journal of Arid Environments 41:6178.CrossRefGoogle Scholar
DUBLIN, H. T., SINCLAIR, A. R. E. & MCGLADE, J. 1990. Elephants and fire as causes of multiple stable states in the Serengeti-Mara woodlands. Journal of Animal Ecology 59:11471164.CrossRefGoogle Scholar
ECKHARDT, H. C., VAN WILGEN, B. W. & BIGGS, H. C. 2000. Trends in woody vegetation cover in the Kruger National Park, South Africa between 1940 and 1998. African Journal of Ecology 38:108115.CrossRefGoogle Scholar
GADD, M. E. 2002. The impact of elephants on the marula tree Sclerocarya birrea. African Journal of Ecology 40:328336.CrossRefGoogle Scholar
GAYLARD, A., OWEN-SMITH, N. & REDFERN, J. 2003. Surface water availability: Implications for heterogeneity and ecosystem process. Pp. 332348 in du Toit, J. T., Rogers, K. H. & Biggs, H. C. (eds.). The Kruger experience. Island Press, Chicago.Google Scholar
HIGGINS, S. I., BOND, W. J. & TROLLOPE, W. S. W. 2000. Fire, resprouting and variability: a recipe for grass–tree coexistence in savanna. Journal of Ecology 88:213229.CrossRefGoogle Scholar
JACOBS, O. S. & BIGGS, R. 2002. The status and population structure of the marula in Kruger National Park. South African Journal of Wildlife Research 32:112.Google Scholar
JELTSCH, F., MILTON, S. J., DEAN, W. R. J. & VAN ROOYEN, N. 1996. Tree spacing and coexistence in semiarid savannas. Journal of Ecology 84:583595.CrossRefGoogle Scholar
JOHNSON, C. F., COWLING, R. M. & PHILIPSON, P. B. 1999. The flora of the Addo Elephant National Park, South Africa: are threatened species vulnerable to elephant damage? Biodiversity and Conservation 8:14471456.CrossRefGoogle Scholar
LAWS, R. M. 1970. Elephants as agents of habitats and landscape change in East Africa. Oikos 21:115.CrossRefGoogle Scholar
LOMBARD, A. T., JOHNSON, C. F., COWLING, R. M. & PRESSEY, R. L. 2001. Protecting plants from elephants: botanical reserve scenarios within the Addo Elephant National Park, South Africa. Biological Conservation 102:191203.CrossRefGoogle Scholar
MAPAURE, I. N. & CAMPBELL, B. M. 2002. Changes in miombo woodland cover in and around Sengwa Wildlife Research Area, Zimbabwe, in relation to elephants and fire. African Journal of Ecology 40:212219.CrossRefGoogle Scholar
MIDGLEY, J. J., BALFOUR, D. & KERLEY, G. 2005. Why do elephants damage savanna trees? South African Journal of Science 101:213215.Google Scholar
NELLEMANN, C., MOE, S. R. & RUTINA, L. P. 2002. Links between terrain characteristics and forage patterns of elephants (Loxodonta africana) in northern Botswana. Journal of Tropical Ecology 18:835844.CrossRefGoogle Scholar
OLFF, H. & RITCHIE, M. E. 1998. Effects of herbivores on grassland plant diversity. Trends in Ecology and Evolution 13:261265.CrossRefGoogle ScholarPubMed
OWEN-SMITH, R. N. 1992. Megaherbivores: the influence of very large body size on ecology. Cambridge University Press, Cambridge. 300 pp.Google Scholar
OWEN-SMITH, R. N. 1996. Ecological guidelines for water points in extensive protected areas. South African Journal of Wildlife Research 26:107112.Google Scholar
OWEN-SMITH, N., KERLEY, G. I. H., PAGE, B., SLOTOW, R. & VAN AARDE, R. J. 2006. A scientific perspective on the management of elephants in the Kruger National Park and elsewhere. South African Journal of Science 102:389394.Google Scholar
PRINS, H. T. & VAN DER JEUGD, H. P. 1993. Herbivore population crashes and woodland structure in East Africa. Journal of Ecology 81:305314.CrossRefGoogle Scholar
REDFERN, J. V., GRANT, R., BIGGS, H. & GETZ, W. M. 2003. Surface water constraints on herbivore foraging in the Kruger National Park, South Africa. Ecology 84:20922107.CrossRefGoogle Scholar
REPTON, M. 2007. Vegetation utilization by elephants in the Mkhuzi and Phinda Game Reserves. M.Sc. Thesis, University of KwaZulu-Natal, Durban.Google Scholar
ROGERS, K. H. 2003. Adopting a hetereogeneity paradigm: implications for management of protected savannas. Pp. 4159 in du Toit, J. T., Rogers, K. H. & Biggs, H. C. (eds.). The Kruger experience. Island Press, Chicago.Google Scholar
RUESS, R. W. 1987. The role of large herbivores in nutrient cycling of tropical savannas. Pp. 6791 in Walker, B. H. (ed.). Determinants of tropical savannas. ICSU Press, Miami.Google Scholar
SCHOLES, R. J. & ARCHER, S. R. 1997. Tree-grass interactions in savannas. Annual Review of Ecology and Systematics 28:517544.CrossRefGoogle Scholar
SHANNON, G., PAGE, B. R., DUFFY, K. J. & SLOTOW, R. 2006a. The role of foraging behaviour in the sexual segregation of the African elephant. Oecologia 150;344354.CrossRefGoogle ScholarPubMed
SHANNON, G., PAGE, B., DUFFY, K. & SLOTOW, R. 2006b. African elephant home range and habitat selection in Pongola Game Reserve, South Africa. African Zoology 41:3744.CrossRefGoogle Scholar
SKARPE, C., AARRESTAD, P. A., ANDREASSEN, H. P., DHILLION, S. S., DIMAKATSO, D., DU TOIT, J., HALLEY, D. J., HYTTEBORN, H., MAKHABU, S., MARI, M., MAROKANE, W., MASUNGA, G., MODISE, D., MOE, S. R., MOJAPHOKO, R., MOSUGELO, D., MOTSUMI, S., NEO-MAHUPELENG, G., RAMOTADIMA, M., RUTINA, L., SECHELE, L., SEJOE, T. B., STOKKE, S., SWENSON, J. E., TAOLO, C., VANDEWALLE, M. & WEGGE, P. 2004. The return of the giants: ecological effects of an increasing elephant population. Ambio 33:276282.CrossRefGoogle ScholarPubMed
STAVER, A. C., BOND, W. J. & FEBRUARY, E. C. 2007. Continuous v. episodic recruitment in Acacia karroo in Hluhluwe-imfolozi Park: implications for understanding savanna structure and dynamics. South African Journal of Botany 73:314.CrossRefGoogle Scholar
THRASH, I., NEL, P. J., THERON, G. K. & DU TOIT, J. 1991. The impact of the provision of water for game on the woody vegetation around a dam in the Kruger National Park. Koedoe 34:131148.Google Scholar
TROLLOPE, W. S. W., TROLLOPE, L. A., BIGGS, H. C., PIENAAR, D. & POTGIETER, A. L. F. 1998. Long-term changes in the woody vegetation of the Kruger National Park, with special reference to the effects of elephants and fire. Koedoe 41:103112.CrossRefGoogle Scholar
VAN DE KOPPEL, J. & PRINS, H. H. T. 1998. The importance of herbivore interactions for the dynamics of African savanna woodlands: an hypothesis. Journal of Tropical Ecology 14:565576.CrossRefGoogle Scholar
VAN DE VIJVER, C. A. D. M., FOLEY, C. A. & OLFF, H. 1999. Changes in the woody component of an east African savanna during 25 years. Journal of Tropical Ecology 15:545564.CrossRefGoogle Scholar
VENTER, F. J., SCHOLES, R. J. & ECKHARDT, H. C. 2003. The abiotic template and its associated vegetation pattern. Pp. 83129 in du Toit, J. T., Rogers, K. H. & Biggs, H. C. (eds.). The Kruger experience. Island Press, Chicago.Google Scholar
WHYTE, I., VAN AARDE, R. & PIMM, S. L. 1998. Managing the elephants of Kruger National Park. Animal Conservation 1:7783.CrossRefGoogle Scholar
WHYTE, I., VAN AARDE, R. & PIMM, S. L. 2003. Kruger's elephant population: Its size and consequences for ecosystem heterogeneity. Pp. 332348 in du Toit, J. T., Rogers, K. H. & Biggs, H. C. (eds.). The Kruger experience. Island Press, Chicago.Google Scholar
WIEGAND, K., SALTZ, D. & WARD, D. 2006. A patch-dynamics approach to savanna dynamics and woody plant encroachment – insights from an arid savanna. Perspectives in Plant Ecology, Evolution and Systematics 7:229242.CrossRefGoogle Scholar
ZENG, N. & NEELIN, J. D. 2000. The role of vegetation-climate interaction and interannual variability in shaping the African savanna. Journal of Climate 13:26652670.2.0.CO;2>CrossRefGoogle Scholar