Native ungulates of diverse body sizes collectively regulate long-term woody plant demography and structure of a semi-arid savanna

Journal of Ecology

Volumn 101, Issue 6, 2013, Pages 1389-1399

  Sankaran, Mahesh ^a,b   Augustine, David J ^c   Ratnam, Jayashree ^a  

^a TATA INSTITUTE OF FUNDAMENTAL RESEARCH   (India)

^b UNIVERSITY OF LEEDS   (United Kingdom)

^c AGRICULTURAL RESEARCH SERVICE   (United States)

Author keywords

Africa; Browsing; Dik dik; Elephant; Mortality; Plant herbivore interactions; Recruitment; Shrub encroachment; Top down control

Indexed keywords

BIOMASS; BROWSING; DEMOGRAPHY; ECOSYSTEM SERVICE; ELEPHANT; EXCLUSION EXPERIMENT; EXTINCTION; HERBIVORE; MORTALITY; PLANT COMMUNITY; PLANT-HERBIVORE INTERACTION; RECRUITMENT (POPULATION DYNAMICS); SAVANNA; SEEDLING; SURVIVAL; TOP-DOWN CONTROL; UNGULATE; WOODY PLANT;

EAST AFRICA;

MAMMALIA; UNGULATA;

EID: 84885853437     PISSN: 00220477     EISSN: 13652745     Source Type: Journal    
DOI: 10.1111/1365-2745.12147     Document Type: Article

References (64)

1. Ahn, P.M. & Geiger, L.C. (1987) Kenya Soil Survey - Soils of Laikipia District. Ministry of Agriculture, National Agricultural Laboratories, Kabete, Kenya.
2. Augustine, D.J. (2003) Spatial heterogeneity in the herbaceous layer of a semi-arid savanna ecosystem. Plant Ecology, 167, 319-332.
3. Augustine, D.J. (2010) Response of native ungulates to drought in semi-arid Kenyan rangeland. African Journal of Ecology, 48, 1009-1020.
4. Augustine, D.J. & McNaughton, S.J. (1998) Ungulate effects on the functional species composition of plant communities: herbivore selectivity and plant tolerance. Journal of Wildlife Management, 62, 1165-1183.
5. Augustine, D.J. & McNaughton, S.J. (2004) Regulation of shrub dynamics by native browsing ungulates on East African rangeland. Journal of Applied Ecology, 41, 45-58.
6. Barnes, M.E. (2001) Effects of large herbivores and fire on the regeneration of Acacia erioloba woodlands in Chobe National Park, Botswana. African Journal of Ecology, 39, 340-350.
7. 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, 1331-1341.
8. Belsky, A.J. (1984) The role of small browsing mammals in preventing woodland regeneration in the Serengeti National Park, Tanzania. African Journal of Ecology, 22, 271-279.
9. Ben-Shahar, R. (1996) Woodland dynamics under the influence of elephants and fire in northern Botswana. Vegetation, 123, 153-163.
10. Birkett, A. & Stevens-Wood, B. (2005) Effect of low rainfall and browsing by large herbivores on an enclosed savanna habitat in Kenya. African Journal of Ecology, 43, 123-130.
11. Bond, W.J. (2005) Large parts of the world are brown or black: a different view on the 'Green World' hypothesis. Journal of Vegetation Science, 16, 261-266.
12. Bond, W.J. (2008) What limits trees in C4 grasslands and savannas? Annual Review of Ecology Evolution & Systematics, 39, 641-659.
13. Bond, W.J. & Loffell, D. (2001) Introduction of giraffe changes acacia distribution in a South African savanna. African Journal of Ecology, 39, 286-294.
14. Bond, W.J., Midgley, G.F. & Woodward, F.I. (2003) What controls South African vegetation - climate or fire? South African Journal of Botany, 69, 79-91.
15. Crawley, M.J. (1983) Herbivory: The Dynamics of Animal-Plant Interactions. University of California Press, Berkeley, CA.
16. Deshmukh, I. (1992) Estimation of wood biomass in the Jubba Valley, southern Somalia, and its application to East African rangelands. African Journal of Ecology, 30, 127-136.
17. 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, 1147-1164.
18. Epp, H., Herlocker, D. & Peden, D. (1982) The use of large scale aerial photography to determine wood biomass in the arid and semi-arid areas of Kenya. Kenya Rangeland Ecological Monitoring Unit. Technical Report Series No. 51, Kenya Rangeland Ecological Monitoring Unit, Nairobi, Kenya.
19. Fornara, D. & Du Toit, J.T. (2008) Responses of woody saplings exposed to chronic mammalian herbivory in an African savanna. Ecoscience, 15, 129-135.
20. Frank, L.G., Woodroffe, R. & Ogada, M.O. (2005) People and predators in Laikipia district, Kenya. People and Wildlife: Conflict or Co-Existence? (eds R. Woodroffe, S. Thirgood & A. Rabinowitz), pp. 286-304. Cambridge University Press, Cambridge.
21. Frost, P.G.H. & Robertson, F. (1987) The ecological effects of fire in savannas. Determinants of Tropical Savannas (ed. B.H. Walker), pp. 93-141. Int. Union Biol. Sci., Paris.
22. Goheen, J.R. & Palmer, T.M. (2010) Defensive plant-ants stabilize megaherbivore-driven landscape change. Current Biology, 20, 1766-1772.
23. Goheen, J.R., Keesing, F., Allan, B.F., Ogada, D. & Ostfeld, R.S. (2004) Net effects of large mammals on Acacia seedling survival in an African savanna. Ecology, 85, 1555-1561.
24. Goheen, J.R., Young, T.P., Keesing, F. & Palmer, T.M. (2007) Consequences of herbivory by native ungulates for the reproduction of a savanna tree. Journal of Ecology, 95, 129-138.
25. Gordijn, P.J., Rice, E. & Ward, D. (2012) The effects of fire on woody plant encroachment are exacerbated by succession of trees of decreased palatability. Perspectives in Plant Ecology, Evolution & Systematics, 14, 411-422.
26. Guldemond, R. & van Aarde, R. (2008) A meta-analysis of the impact of African elephants on savanna vegetation. Journal of Wildlife Management, 72, 892-899.
27. Hean, J.W. & Ward, D. (2012) Fire and herbivory are not substitutable: evidence from regrowth patterns and changes in physical and chemical defences in Acacia seedlings. Journal of Vegetation Science, 23, 13-23.
28. 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, 213-229.
29. Hoffmann, W.A. (1999) Fire and population dynamics of woody plants in a neotropical savanna: matrix model projections. Ecology, 80, 1354-1369.
30. Holdo, R.M. (2003) Woody plant damage by African elephants in relation to leaf nutrients in Western Zimbabwe. Journal of Tropical Ecology, 19, 189-196.
31. Holdo, R.M. (2007) Elephants, fire, and frost can determine community structure and composition in Kalahari woodlands. Ecological Applications, 17, 558-568.
32. Holdo, R.M., Holt, R.D. & Fryxell, J.M. (2009) Grazers, browsers and fire influence the extent and spatial pattern of tree cover in the Serengeti. Ecological Applications, 19, 95-109.
33. House, J., Archer, S., Breshears, D.D., Scholes, R.J. & N.C.E.A.S. Tree-Grass Interaction Participants (2003) Conundrums in mixed woody-herbaceous plant systems. Journal of Biogeography, 30, 1763-1777.
34. Kalwij, J.M., de Boer, W.F., Mucina, L., Prins, H.H.T., Skarpe, C. & Winterbach, C. (2010) Tree cover and biomass increase in a southern African savanna despite growing elephant population. Ecological Applications, 20, 222-233.
35. Keuhl, R.O. (2000) Design of Experiments: Statistical Principles of Research Design and Analysis. Duxbury Press, Belmont, CA, USA.
36. Kraaij, T. & Ward, D. (2006) Effects of rain, nitrogen, fire and grazing on tree recruitment and early survival in bush-encroached savanna, South Africa. Plant Ecology, 186, 235-246.
37. Levick, S. & Rogers, K. (2008) Patch and species specific responses of savanna woody vegetation to browser exclusion. Biological Conservation, 141, 489-498.
38. MacLean, J.E., Goheen, J.R., Doak, D.F., Palmer, T.M. & Young, T.P. (2011) Cryptic herbivores mediate the strength and form of ungulate impacts on a long-lived savanna tree. Ecology, 92, 1626-1636.
39. Mapaure, I. & Moe, S.R. (2009) Changes in the structure and composition of miombo woodlands mediated by elephants (Loxodonta africana) and fire over a 26-year period in north-western Zimbabwe. African Journal of Ecology, 47, 175-183.
40. Midgley, J.J., Lawes, M.J. & Chamaillé-Jammes, S. (2010) Savanna woody plant dynamics: the role of fire and herbivory, separately and synergistically. Australian Journal of Botany, 58, 1-11.
41. Moe, S.R., Rutina, L.P., Hytteborn, H. & Du Toit, J.T. (2009) What controls woodland regeneration after elephants have killed the big trees? Journal of Applied Ecology, 46, 223-230.
42. Murphy, B.P., Russell-Smith, J. & Prior, L.D. (2010) Frequent fires reduce tree growth in northern Australian savannas: implications for tree demography and carbon sequestration. Global Change Biology, 16, 331-343.
43. Prins, H.H.T. & van der Jeugd, H.P. (1993) Herbivore population crashes and woodland structure in East Africa. Journal of Ecology, 81, 305-314.
44. Riginos, C. (2009) Grass competition suppresses savanna tree growth across multiple demographic stages. Ecology, 90, 335-340.
45. Riginos, C. & Young, T.P. (2007) Positive and negative effects of grass, cattle, and wild herbivores on Acacia saplings in an East African savanna. Oecologia, 153, 985-995.
46. Ritchie, M.E. & Olff, H. (1999) Herbivore diversity and plant dynamics: compensatory and additive effects. Herbivores: Between Plants and Predators (eds H. Olff, V.K. Brown & R.H. Drent), pp. 175-204. Blackwell Science Ltd, Oxford.
47. Roques, K.G., O'Connor, T.G. & Watkinson, A.R. (2001) Dynamics of shrub encroachment in an African savanna: relative influences of fire, herbivory, rainfall and density dependence. Journal of Applied Ecology, 38, 268-280.
48. Sankaran, M., Ratnam, J. & Hanan, N.P. (2004) Tree-grass coexistence in savannas revisited - insights from an examination of assumptions and mechanisms invoked in existing models. Ecology Letters, 7, 480-490.
49. Sankaran, M., Ratnam, J. & Hanan, N. (2008) Woody cover in African savannas: the role of resources, fire and herbivory. Global Ecology and Biogeography, 17, 236-245.
50. Sankaran, M., Hanan, N. P., Scholes, R. J., Ratnam, J., Cade, B. S., Ardo, J. et al. (2005) Determinants of woody cover in African savannas. Nature, 438, 846-849.
51. Scholes, R.J. & Archer, S.R. (1997) Tree-grass interactions in savannas. Annual Review of Ecology and Systematics, 28, 517-544.
52. Scogings, P.F., Johansson, T., Hj ltén, J. & Kruger, J. (2012) Responses of woody vegetation to exclusion of large herbivores in semi-arid savannas. Austral Ecology, 37, 56-66.
53. Shannon, G., Thaker, M., Vanak, A.T., Page, B.R., Grant, R. & Slotow, R. (2011) Relative impacts of elephant and fire on large trees in a savanna ecosystem. Ecosystems, 14, 1372-1381.
54. Sharam, G., Sinclair, A.R.E. & Turkington, R. (2006) Establishment of broad-leaved thickets in Serengeti, Tanzania: the influence of fire, browsers, grass competition, and elephants. Biotropica, 38, 599-605.
55. Staver, A.C., Bond, W.J., Stock, W.D., van Rensburg, S.J. & Waldram, M.S. (2009) Browsing and fire interact to suppress tree density in an African savanna. Ecological Applications, 19, 1909-1919.
56. Thouless, C.R. (1995) Long distance movements of elephants in northern Kenya. African Journal of Ecology, 33, 321-334.
57. Tobler, M.S., Cochard, R. & Edwards, P.J. (2003) The impact of cattle ranching on large-scale vegetation patterns in a coastal savanna in Tanzania. Journal of Applied Ecology, 40, 430-444.
58. Vanak, A.T., Shannon, G., Thaker, M., Page, B., Grant, G. & Slotow, R. (2012) Biocomplexity in large tree mortality: interactions between elephant, fire and landscape in an African savanna. Ecography, 35, 315-321.
59. van Vegten, J.A. (1983) Thornbush invasion in a savanna ecosystem in eastern Botswana. Vegetation, 56, 3-7.
60. Williams, R.J., Cook, G.D., Gill, A.M. & Moore, P.H.R. (1999) Fire regime, fire intensity and tree survival in a tropical savanna in northern Australia. Australian Journal of Ecology, 24, 50-59.
61. Woodroffe, R. (2011) Demography of a recovering African wild dog (Lycaon pictus) population. Journal of Mammalogy, 92, 305-315.
62. Woodroffe, R., Lindsey, P.A., Romañach, S.S. & Ole Ranah, S.M.K. (2007) African wild dogs (Lycaon pictus) can subsist on small prey: implications for conservation. Journal of Mammalogy, 88, 181-193.
63. Young, T.P. & Augustine, D.J. (2007) Interspecific variation in the reproductive response of Acacia species to protection from large mammalian herbivores. Biotropica, 39, 559-561.
64. Young, T.P., Okello, B., Kinyua, D. & Palmer, T. (1998) KLEE: a long-term, multi-species herbivore exclusion experiment in Laikipia, Kenya. African Journal of Range and Forage Science, 14, 92-104.