Skip to main content

Advertisement

SpringerLink
Log in

Limited impact of elephants on trees and shrubs in semi-arid thicket vegetation in southern Africa

  • Published:
Plant Ecology Aims and scope Submit manuscript

Abstract

When wide ranging, herbivorous species such as African elephants (Loxodonta africana) are confined and their population densities increase, the vegetation may be negatively affected. Any changes to vegetation structure and complexity may then result in a series of ecological cascades on other plant and animal species that rely on the vegetation for survival. We assessed the composition and structure of the woody and succulent plants within the locally endemic Albany Thicket Biome at five protected areas (reserves) with elephants in the Eastern Cape province, South Africa in 2006 and 2016. We show that when elephant populations in this region are actively managed, wholesale negative impacts on woody thicket plant physiognomy are not observed. In fact, the only statistically detectable change over time, presumably due to elephants, was the toppling of larger, single-stemmed trees. We believe that because the Albany Thicket Biome evolved in the presence of large, top-down browsers such as elephants, the generally negative effects that have been observed of elephants on vegetation in savanna systems are not evident. However, the reserves with elephants in the Eastern Cape are all relatively small (< 400 km2) and fenced which prevents elephant dispersal. Thus, continued monitoring of elephant browsing effects is crucial for the future conservation of this unique biome.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

Data availability

All data will be made available through a Dryad link after acceptance.

References

  • Asner GP, Levick SR (2012) Landscape-scale effects of herbivores on treefall in African savannas. Ecol Lett 15:1211–1217

    Article  PubMed  Google Scholar 

  • Asner GP, Vaughn N, Smit IPJ, Levick S (2016) Ecosystem-scale effects of megafauna in African savannas. Ecography 39:240–252

    Article  Google Scholar 

  • Barton K (2020) MuMIn: multi-model inference. R package version 1.43.17

  • Bates D, Mächler M, Bolker B, Walker S (2015) Fitting linear mixed-effects models using lme4. J Stat Softw 67:1–48

    Article  Google Scholar 

  • Burnham KP, Anderson DR (2010) Model selection and multimodel inference: a practical information-theoretic approach, 2nd edn. Springer, New York, NY, p 488

    Google Scholar 

  • Burnham KP, Anderson DR, Huyvaert KP (2011) AIC model selection and multimodel inference in behavioral ecology: some background, observations, and comparisons. Behav Ecol Sociobiol 65:23–35

    Article  Google Scholar 

  • Calef GW (1988) Maximum rate of increase in the African elephant. Afr J Ecol 26:323–327

    Article  Google Scholar 

  • Cottam G, Curtis JT (1956) The use of distance measures in phytosociological sampling. Ecology 37:451–460

    Article  Google Scholar 

  • Cowling RM, Procheş Ş, Vlok JHJ, Van Staden J (2005) On the origin of southern African subtropical thicket vegetation. S Afr J Bot 71:1–23

    Article  Google Scholar 

  • Dahdouh-Guebas F, Koedam N (2006) Empirical estimate of the reliability of the use of the point-centred quarter method (PCQM): Solutions to ambiguous field situations and description of the PCQM+ protocol. For Ecol Manag 228:1–18

    Article  Google Scholar 

  • Douglas-Hamilton I (1987) African elephants: population trends and their causes. Oryx 21:11–24

    Article  Google Scholar 

  • Fang J, Piao S, Tang Z, Peng C, Ji W (2001) Interannual variability in net primary production and precipitation. Science 293:1723

    Article  CAS  PubMed  Google Scholar 

  • Fowler N (2023) The influence of immuno-contraception on the ecology of African savanna elephants (Loxodonta africana) in a small game reserve in the Eastern Cape, South Africa. MSc thesis, Rhodes University, Makhanda, p 140

  • Gough KF, Kerley GI (2006) Demography and population dynamics in the elephants Loxodonta africana of Addo Elephant National Park, South Africa: is there evidence of density dependent regulation? Oryx 40:434–441

    Article  Google Scholar 

  • Guldemond R, Van Aarde R (2008) A meta-analysis of the impact of African elephants on savanna vegetation. J Wildl Manag 72:892–899

    Article  Google Scholar 

  • Guy PR (1976) The feeding behaviour of elephant (Loxodonta africana) in the Sengwa Area Rhodesia. S Afr J Wildl Res 6:55–63

    Google Scholar 

  • Hayward MW, Kerley GIH (2009) Fencing for conservation: restriction of evolutionary potential or a riposte to threatening processes? Biol Conserv 142:1–13

    Article  Google Scholar 

  • Jachmann H, Bell RHV (1985) Utilization by elephants of the Brachystegia woodlands of the Kasungu National Park, Malawi. Afr J Ecol 23:245–258

    Article  Google Scholar 

  • Kerley GI, Landman M (2006) The impacts of elephants on biodiversity in the Eastern Cape subtropical thickets: elephant conservation. S Afr J Sci 102:395–402

    Google Scholar 

  • Kerley GI, Shrader AM (2007) Elephant contraception: silver bullet or a potentially bitter pill? S Afr J Sci 103:181–182

    Google Scholar 

  • Landman M, Schoeman DS, Hall-Martin AJ, Kerley GIH (2012) Understanding long-term variations in an elephant piosphere effect to manage impacts. PLoS ONE 7:e45334

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Lindsey PA, Romañach SS, Davies-Mostert HT (2009) The importance of conservancies for enhancing the value of game ranch land for large mammal conservation in southern Africa. J Zool 277:99–105

    Article  Google Scholar 

  • Lombard AT, Johnson CF, Cowling RM, Pressey RL (2001) Protecting plants from elephants: botanical reserve scenarios within the Addo Elephant National Park, South Africa. Biol Conserv 102:191–203

    Article  Google Scholar 

  • Lubke R, De Moor IJ (eds) (1998) Field guide to the Eastern & Southern Cape coasts, completely revised 2nd edn. University of Cape Town Press, Rondebosch, South Africa, p 559

    Google Scholar 

  • Lubke RA, Everard DA, Jackson S (1986) The biomes of the Eastern Cape with emphasis on their conservation. Bothalia 16:251–261

    Article  Google Scholar 

  • MacArthur RH, MacArthur JW (1961) On bird species diversity. Ecology 42:594–598

    Article  Google Scholar 

  • Mackey RL, Page BR, Duffy KJ, Slotow R (2006) Modelling elephant population growth in small, fenced, South African reserves. S Afr J Wildl Res 36:33–43

    Google Scholar 

  • Moolman HJ, Cowling RM (1994) The impact of elephant and goat grazing on the endemic flora of South African succulent thicket. Biol Conserv 68:53–61

    Article  Google Scholar 

  • Mucina L, Rutherford MC (eds) (2006) The vegetation of South Africa, Lesotho and Swaziland. South African National Biodiversity Institute, Pretoria, p 807

    Google Scholar 

  • Nuttall-Smith GD (2018) The impact of elephants on the thicket vegetation and other mammals in the Eastern Cape provinces, South Africa. MSc thesis, Rhodes University, Grahamstown, p 135

  • O’brien RM (2007) A caution regarding rules of thumb for variance inflation factors. Qual Quant 41:673–690

    Article  Google Scholar 

  • O’Connor TG, Goodman PS, Clegg B (2007) A functional hypothesis of the threat of local extirpation of woody plant species by elephant in Africa. Biol Conserv 136:329–345

    Article  Google Scholar 

  • Oksanen J, Blanchet FG, Friendly M, Kindt R, Legendre P, McGlinn D, Minchin PR, O’Hara RB, Simpson GL, Solymos P, Szocs E, Wagner HH (2020) vegan community ecology package version 2.5, 7 November 2020

  • Parker DM (2017) The composition and complexity of the woody and succulent components of Albany thicket with and without elephants. S Afr J Bot 112:19–28

    Article  Google Scholar 

  • Parker DM (2019) The elephant in the ‘room’: determinants of songbird assemblages in the Thicket Biome, South Africa. Emu Austral Ornithol 119:157–165

    Article  Google Scholar 

  • Parker DM, Bernard RTF (2008) Lessons from aloes in the Thicket Biome: reconstructing past elephant browsing to understand the present. S Afr J Sci 104:163–164

    Google Scholar 

  • Penzhorn BL, Robbertse PJ, Olivier MC (1974) The influence of the African elephant on the vegetation of the Addo Elephant National Park. Koedoe 17:137–158

    Article  Google Scholar 

  • Roux C, Bernard RTF (2009) Home range size, spatial distribution and habitat use of elephants in two enclosed game reserves in the Eastern Cape Province, South Africa. Afr J Ecol 47:146–153

    Article  Google Scholar 

  • Sankaran M, Hanan NP, Scholes RJ, Ratnam J, Augustine DJ, Cade BS, Gignoux J, Higgins SI, Le Roux X, Ludwig F, Ardo J, Banyikwa F, Bronn A, Bucini G, Caylor KK, Coughenour MB, Diouf A, Ekaya W, Feral CJ, February EC, Frost PGH, Hiernaux P, Hrabar H, Metzger KL, Prins HHT, Ringrose S, Sea W, Tews J, Worden J, Zambatis N (2005) Determinants of woody cover in African savannas. Nature 438:846–849

    Article  CAS  PubMed  Google Scholar 

  • Scogings PF, Dziba LE, Gordon IJ (2004) Leaf chemistry of woody plants in relation to season, canopy retention and goat browsing in a semiarid subtropical savanna. Austral Ecol 29:278–286

    Article  Google Scholar 

  • Skarpe C, Aarrestad PA, Andreassen HP, Dhillion SS, Dimakatso T, Du Toit JT, Halley DJ, Hytteborn H, Makhabu S, Mari M, Marokane W, Masunga G, Modise D, Moe SR, Mojaphoko R, Mosugelo D, Mptsumi S, Neo-Mahupeleng G, Ramotadima M, Rutina L, Sechele L, Sejoe TB, Stokke S, Swenson JE, Taolo C, Vandewalle M, Wegge P (2004) The return of the giants: ecological effects of an increasing elephant population. Ambio 33:276–282

    Article  PubMed  Google Scholar 

  • Skead CJ, Boshoff A, Kerley GIH, Lloyd P (2007) Historical incidence of the larger land mammals in the broader Eastern Cape, 2nd edn (eds Boshoff A, Kerley G, Lloyd P). Centre for African Conservation Ecology, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa, p 570.

  • Stuart-Hill GC (1992) Effects of elephants and goats on the Kaffrarian Succulent Thicket of the Eastern Cape, South Africa. J Appl Ecol 29:699–710

    Article  Google Scholar 

  • Vlok JHJ, Euston-Brown DIW, Cowling RM (2003) Acocks’ Valley Bushveld 50 years on: new perspectives on the delimitation, characterisation and origin of subtropical thicket vegetation. S Afr J Bot 69:27–51

    Article  Google Scholar 

  • Weed AS, Schwarzländer M (2014) Density dependence, precipitation and biological control agent herbivory influence landscape-scale dynamics of the invasive Eurasian plant Linaria dalmatica. J Appl Ecol 51:825–834

    Article  Google Scholar 

  • Western D (1989) The ecological role of elephants in Africa. Pachyderm 12:42–45

    Google Scholar 

Download references

Acknowledgements

All the landowners and managers of the respective reserves for allowing us to conduct research on their properties. Tony Dold of the Albany Museum for aiding in the identification of plant specimens.

Funding

The authors have not disclosed any funding.

Author information

Authors and Affiliations

  1. Wildlife and Reserve Management Research Group, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Makhanda, 6140, South Africa

    Gareth D. Nuttall-Smith

  2. School of Biology and Environmental Sciences, University of Mpumalanga, Private Bag X 11283, Mbombela, South Africa

    Daniel M. Parker

Authors
  1. Gareth D. Nuttall-Smith
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Daniel M. Parker
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

DMP and GNS conceived the idea, DMP and GNS collected the data, DMP and GNS analyzed the data, DMP lead the writing of the manuscript and both authors were involved in the review and revision of drafts.

Corresponding author

Correspondence to Daniel M. Parker.

Ethics declarations

Conflict of interest

The authors have no competing interests.

Additional information

Communicated by Neal Enright.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 35 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Nuttall-Smith, G.D., Parker, D.M. Limited impact of elephants on trees and shrubs in semi-arid thicket vegetation in southern Africa. Plant Ecol 224, 931–941 (2023). https://doi.org/10.1007/s11258-023-01348-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11258-023-01348-8

Keywords

Search

Navigation