Water availability, bedrock, disturbance by herbivores, and climate determine plant diversity in South-African savanna
1.Gaston, K. J., Jackson, S. F., Cantú-Salazar, L. & Cruz-Piñón, G. The ecological performance of protected areas. Annu. Rev. Ecol. Evol. Syst. 39, 93–113 (2008).
Google Scholar
2.Staver, A. C., Abraham, J. O., Hempson, G. P., Karp, A. T. & Faith, J. T. The past, present, and future of herbivore impacts on savanna vegetation. J. Ecol. 109, 2804–2822 (2021).
Google Scholar
3.Bond, W. J. Keystone species. In Biodiversity and Ecosystem Function (eds Schulze, E. D. & Mooney, H. A.) 237–253 (Springer, 1994).
Google Scholar
4.Cole, M. M. The influence of soils, geomorphology and geology on the distribution of plant communities in savanna ecosystems. In Ecology of Tropical Savannas (eds Huntley, B. J. & Walker, B. H.) 145–174 (Springer, 1982).
Google Scholar
5.Huntley, B. J. & Walker, B. H. (eds) Ecology of Tropical Savannas Vol. 42 (Springer, 1982).
Google Scholar
6.Frost, P. et al. Responses of Savannas to Stress and Disturbance: A Proposal for a Collaborative Programme of Research (Biology International 10, 1985).
Google Scholar
7.Medina, E. & Silva, J. F. Savannas of northern South America: A steady state regulated by water–ire interactions on a background of low nutrient availability. J. Biogeogr. 17, 403–413 (1990).
Google Scholar
8.Fensham, R. J., Fairfax, R. J. & Archer, S. R. Rainfall, land use and woody vegetation cover change in semi-arid Australian savanna. J. Ecol. 93, 596–606 (2005).
Google Scholar
9.Mucina, L. & Rutherford, M. C. The Vegetation of South Africa, Lesotho and Swaziland (South African National Biodiversity Institute, 2006).
Google Scholar
10.Staver, A. C., Botha, J. & Hedin, L. Soils and fire jointly determine vegetation structure in an African savanna. New Phytol. 216, 1151–1160 (2017).CAS
PubMed
Google Scholar
11.Jakubka, D. et al. Effects of climate, habitat and land use on the cover and diversity of the savanna herbaceous layer in Burkina-Faso, West Africa. Folia Geobot. 52, 129–142 (2017).
Google Scholar
12.Bond, W. J. Open Ecosystems: Ecology and Evolution Beyond the Forest Edge (Oxford University Press, 2019).
Google Scholar
13.O’Connor, T. G. Composition and population responses of an African savanna grassland to rainfall and grazing. J. Appl. Ecol. 31, 155–171 (1994).
Google Scholar
14.Walker, B. & Langridge, J. Predicting savanna vegetation structure on the basis of plant available moisture (PAM) and plant available nutrients (PAN): A case study from Australia. J. Biogeogr. 24, 813–825 (1997).
Google Scholar
15.Sankaran, M. et al. Determinants of woody cover in African savannas. Nature 438, 846–849 (2005).CAS
ADS
PubMed
Google Scholar
16.Bucini, G. & Hanan, N. P. A continental-scale analysis of tree cover in African savannas. Glob. Ecol. Biogeogr. 16, 593–605 (2007).
Google Scholar
17.Venter, F. J., Scholes, R. J. & Eckhardt, H. C. The abiotic template and its associated vegetation pattern. In The Kruger Experience: Ecology and Management of Savanna Heterogeneity (eds du Toit, J. T. et al.) 83–129 (Island Press, Washington, D.C., 2003).18.Valeix, M. et al. Vegetation structure and ungulate abundance over a period of increasing elephant abundance in Hwange National Park, Zimbabwe. J. Trop. Ecol. 23, 87–93 (2007).
Google Scholar
19.Asner, G. P. et al. Large-scale impacts of herbivores on the structural diversity of African savannas. Proc. Natl Acad. Sci. USA 106, 4947–4952 (2009).CAS
ADS
PubMed
PubMed Central
Google Scholar
20.Archibald, S. & Hempson, G. P. Competing consumers: Contrasting the patterns and impacts of fire and mammalian herbivory in Africa. Philos. Trans. R. Soc. B 371, 20150309 (2016).
Google Scholar
21.Archibald, S., Bond, W. J., Stock, W. D. & Fairbanks, D. H. K. Shaping the landscape: Fire–grazer interactions in an African savanna. Ecol. Appl. 15, 96–109 (2005).
Google Scholar
22.Staver, A. C. & Bond, W. J. Is there a ‘browse trap’? Dynamics of herbivore impacts on trees and grasses in an African savanna. J. Ecol. 102, 595–602 (2014).
Google Scholar
23.Jeltsch, F., Weber, G. E. & Grimm, V. Ecological buffering mechanisms in savannas: A unifying theory of long-term tree-grass coexistence. Plant Ecol. 105, 161–171 (2000).
Google Scholar
24.February, E. C., Higgins, S. I., Bond, W. J. & Swemmer, L. Influence of competition and rainfall manipulation on the growth responses of savanna trees and grasses. Ecology 94, 1155–1164 (2013).PubMed
Google Scholar
25.Savadogo, P., Tiveau, D., Sawadogo, L. & Tigabu, M. Herbaceous species responses to long-term effects of prescribed fire, grazing and selective tree cutting in the savanna-woodlands of West Africa. Perspect. Plant Ecol. Evol. Syst. 10, 179–195 (2008).
Google Scholar
26.Smith, M. D. et al. Long-term effects of fire frequency and season on herbaceous vegetation in savannas of the Kruger National Park, South Africa. J. Plant Ecol. 6, 71–83 (2013).
Google Scholar
27.Thrash, I. Impact of water provision on herbaceous vegetation in Kruger National Park, South Africa. J. Arid Environ. 38, 437–450 (1998).ADS
Google Scholar
28.Staver, A. C., Bond, W. J., Stock, W. D., van Rensburg, S. J. & Waldram, M. S. Browsing and fire interact to suppress tree density in an African savanna. Ecol. Appl. 19, 1909–1919 (2009).PubMed
Google Scholar
29.Smit, I. P. J. & Ferreira, S. M. Management intervention affects river-bound spatial dynamics of elephants. Biol. Conserv. 143, 2172–2181 (2010).
Google Scholar
30.Loarie, S. R., van Aarde, R. J. & Pimm, S. L. Elephant seasonal vegetation preferences across dry and wet savannas. Biol. Conserv. 142, 3099–3107 (2009).
Google Scholar
31.Young, K. D., Ferreira, S. M. & Van Aarde, R. J. Elephant spatial use in wet and dry savannas of southern Africa. J. Zool. 278, 189–205 (2009).
Google Scholar
32.Codron, J. et al. Elephant (Loxodonta africana) diets in Kruger National Park, South Africa: spatial and landscape differences. J. Mammal. 87, 27–34 (2006).
Google Scholar
33.Timberlake, J. Colophospermum mopane: Annotated Bibliography and Review (Zimbabwe Bulletin of Forestry Research No. 11, 1995).
Google Scholar
34.Pyšek, P. et al. Into the great wide open: Do alien plants spread from rivers to dry savanna in the Kruger National Park?. NeoBiota 60, 61–77 (2020).
Google Scholar
35.Eckhardt, H. C., van Wilgen, B. W. & Biggs, H. C. Trends in woody vegetation cover in the Kruger National Park, South Africa, between 1940 and 1998. Afr. J. Ecol. 38, 108–115 (2000).
Google Scholar
36.Groen, T. A. Spatial Matters: How Spatial Patterns and Processes Affect Savanna Dynamics. PhD Thesis, Wageningen University, The Netherlands (2007).37.MacFadyen, S., Hui, C., Verburg, P. H. & Van Teeffelen, A. J. A. Quantifying spatiotemporal drivers of environmental heterogeneity in Kruger National Park, South Africa. Landsc. Ecol. 31, 2013–2029 (2016).
Google Scholar
38.Munyati, C. & Ratshibvumo, T. Differentiating geological fertility derived vegetation zones in Kruger National Park, SouthAfrica, using Landsat and MODIS imagery. J. Nat. Conserv. 18, 169–179 (2010).
Google Scholar
39.Colgan, M. S., Asner, G. P., Levick, S. R., Martin, R. E. & Chadwick, O. A. Topo-edaphic controls over woody plant biomass in South African savannas. Biogeosciences 9, 1809–1821 (2012).ADS
Google Scholar
40.Walter, H. & Burnett, J. H. Ecology of Tropical and Subtropical Vegetation Vol. 539 (Oliver and Boyd, 1971).
Google Scholar
41.Scholes, R. J., Bond, W. J. & Eckhardt, H. C. Vegetation dynamics in the Kruger ecosystem. In The Kruger Experience: Ecology and Management of Savanna Heterogeneity (eds du Toit, J. T. et al.) 243–262 (Island Press, 2003).
Google Scholar
42.Knoop, W. T. & Walker, B. H. Interactions of woody and herbaceous vegetation in southern African savanna. J. Ecol. 73, 235–253 (1985).
Google Scholar
43.Tilman, D. The resource-ratio hypothesis of plant succession. Am. Nat. 125, 827–852 (1985).
Google Scholar
44.Scholes, R. J. & Archer, S. R. Tree–grass interactions in savannas. Annu. Rev. Ecol. Syst. 28, 517–544 (1997).
Google Scholar
45.Muvengwi, J., Davies, A. B., Parrini, F. & Witkowski, E. T. F. Contrasting termite diversity and assemblages on granitic and basaltic African savanna landscapes. Insect. Soc. 65, 25–35 (2018).
Google Scholar
46.Trollope, W. S. W., Potgieter, A. L. F. & Zambatis, N. Assessing veld condition in the Kruger National Park using key grass species. Koedoe 32, 67–93 (1989).
Google Scholar
47.Ehleringer, J. R. & Monson, R. K. Evolutionary and ecological aspects of photosynthetic pathway variation. Annu. Rev. Ecol. Syst. 24, 411–439 (1993).
Google Scholar
48.Chytrý, M., Tichý, L. & Roleček, J. Local and regional patterns of species richness in Central European vegetation types along the pH/calcium gradient. Folia Geobot. 38, 429–442 (2003).
Google Scholar
49.Owen-Smith, N., Page, B., Teren, G. & Druce, D. J. Megabrowser impacts on woody vegetation in savannas. In Savanna Woody Plants and Large Herbivores (eds Scogings, P. F. & Sankaran, M.) 585–611 (Wiley, 2019).
Google Scholar
50.Nasseri, N. A., McBrayer, L. D. & Schulte, B. A. The impact of tree modification by African elephant (Loxodonta africana) on herpetofaunal species richness in northern Tanzania. Afr. J. Ecol. 49, 133–140 (2010).
Google Scholar
51.Asner, G. P. & Levick, S. R. Landscape-scale effects of herbivores on treefall in African savannas. Ecol. Lett. 15, 1211–1217 (2012).PubMed
Google Scholar
52.Haynes, G. Elephants (and extinct relatives) as earth-movers and ecosystem engineers. Geomorphology 157, 99–107 (2012).ADS
Google Scholar
53.Kruger, L. M., Coetzee, J. A. & Vickers, K. The Impacts of Elephants on Woodlands and Associated Biodiversity (Summary report to South African National Parks, Organization for Tropical Studies, 2007).54.Guy, P. R. The influence of elephants and fire on a Brachystegia julbernardia woodland in Zimbabwe. J. Trop. Ecol. 5, 215–226 (1989).
Google Scholar
55.Laws, R. M., Parker, I. S. C. & Johnstone, R. C. B. Elephants and Their Habitats: The Ecology of Elephants in North Bunyoro, Uganda (Clarendon Press, 1975).
Google Scholar
56.Thompson, P. J. The role of elephants, fire and other agents in the decline of Brachystegia woodlands. J. S. Afr. Wildl. Manag. Assoc. 5, 11–18 (1975).
Google Scholar
57.Barnes, M. E. Effects of large herbivores and fire on the regeneration of Acacia erioloba woodlands in Chobe National Park, Botswana. Afr. J. Ecol. 39, 340–350 (2001).
Google Scholar
58.Scogings, P. F., Johansson, T., Hjältén, J. & Kruger, J. Responses of woody vegetation to exclusion of large herbivores in semi-arid savannas. Austral Ecol. 37, 56–66 (2012).
Google Scholar
59.Verweij, R. J. T., Higgins, S. I., Bond, W. J. & February, E. C. Water sourcing by trees in a mesic savanna: Responses to severing deep and shallow roots. Environ. Exp. Bot. 74, 229–236 (2011).
Google Scholar
60.Smit, I. et al. Effects of fire on woody vegetation structure in African savanna. Ecol. Appl. 20, 1865–1875 (2010).PubMed
Google Scholar
61.MacFadyen, S., Hui, C., Verburg, P. H. & Van Teeffelen, A. J. A. Spatiotemporal distribution dynamics of elephants in response to density, rainfall, rivers and fire in Kruger National Park, South Africa. Divers. Distrib. 25, 880–894 (2019).
Google Scholar
62.O’Connor, T. G., Goodman, P. S. & Clegg, B. A functional hypothesis of the threat of local extirpation of woody plant species by elephant in Africa. Biol. Conserv. 136, 329–345 (2007).
Google Scholar
63.Didan, K. MOD13Q1 MODIS/Terra Vegetation Indices 16-Day L3 Global 250m SIN Grid V006. NASA EOSDIS Land Processes DAAC. Accessed 2021-06-08 from https://doi.org/10.5067/MODIS/MOD13Q1.006 (2015).64.Kreft, H. & Jetz, W. Global patterns and determinants of vascular plant diversity. Proc. Natl Acad. Sci. 104, 5925–5930 (2007).CAS
ADS
PubMed
PubMed Central
Google Scholar
65.Bohdalková, E., Toszogyova, A., Šímová, I. & Storch, D. Universality in biodiversity patterns: variation in species-temperature and species-productivity relationships reveals a prominent role of productivity in diversity gradients. Ecography 44, 1366–1378 (2021).
Google Scholar
66.Knight, R. S., Crowe, T. M. & Siegfried, W. R. Distribution and species richness of trees in southern Africa. J. S. Afr. Bot. 48, 455–480 (1982).
Google Scholar
67.Gaylard, A., Owen-Smith, N. & Redfern, J. Surface water availability: implications for heterogeneity and eco-system processes. In The Kruger Experience: Ecology and Management of Savanna Heterogeneity (eds du Toit, J. T. et al.) 171–188 (Island Press, 2003).
Google Scholar
68.Venter, F. J. A Classification of Land for Management Planning in the Kruger National Park. PhD Thesis, University of South Africa (1990).69.du Toit, J. T. et al. (eds) The Kruger Experience: Ecology and Management of Savanna Heterogeneity (Island Press, 2003).
Google Scholar
70.Smit, I. P. J., Smit, C. F., Govender, N., van der Linde, M. & MacFadyen, S. Rainfall, geology and landscape position generate large-scale spatiotemporal fire pattern heterogeneity in an African savanna. Ecography 36, 447–459 (2013).
Google Scholar
71.Obermeijer, A. A. A preliminary list of plants found in the Kruger National Park. Ann. Transvaal Mus. 17, 185–227 (1937).
Google Scholar
72.van der Schijff, H. P. ‘n Ekologiese Studie van die Flora van die Nasionale Krugerwildtuin. D.Sc. Thesis, Potchefstroom University (1957).73.van der Schijff, H. P. The affinities of the flora of the Kruger National Park. Kirkia 7, 109–120 (1968).
Google Scholar
74.Coetzee, B. J. Phytosociology, Vegetation Structure and Landscapes of the Central District. Kruger National Park, South Africa. Dissertationes Botanicae, J. Cramer, Vaduz (1983).75.Gertenbach, W. P. D. Landscapes of the Kruger National Park. Koedoe 26, 9–121 (1983).
Google Scholar
76.Siebert, F. & Eckhardt, H. C. The vegetation and floristics of the Nkhuhlu exclosures, Kruger National Park. Koedoe 50, 126–144 (2008).
Google Scholar
77.Siebert, F., Eckhardt, H. C. & Siebert, S. J. The vegetation and floristics of the Letaba exclosures, Kruger National Park, South Africa. Koedoe 52, 1–12 (2010).
Google Scholar
78.Wigley, B. J., Fritz, H., Coetsee, C. & Bond, W. J. Herbivores shape woody plant communities in the Kruger National Park: Lessons from three long-term exclosures. Koedoe 56, 1–12 (2014).
Google Scholar
79.Enslin, B. W., Potgieter, A. L. F., Biggs, H. C. & Biggs, R. Long term effects of fire frequency and season on the woody vegetation dynamics of the Sclerocarya birrea/Acacia nigrescens savanna of the Kruger National Park. Koedoe 43, 27–37 (2000).
Google Scholar
80.Brits, J., Van Rooyen, M. W. & Van Rooyen, N. Ecological impact of large herbivores on the woody vegetation at selected watering points on the eastern basaltic soils in the Kruger National Park. Afr. J. Ecol. 40, 53–60 (2002).
Google Scholar
81.Todd, S. W. Gradients in vegetation cover, structure and species richness of Nama-Karoo shrublands in relation to distance from livestock watering points. J. Appl. Ecol. 43, 293–304 (2006).
Google Scholar
82.Foxcroft, L. C., Henderson, L., Nichols, G. R. & Martin, B. W. A revised list of alien plants for the Kruger National Park. Koedoe 46, 21–44 (2003).
Google Scholar
83.Foxcroft, L. C., Richardson, D. M. & Wilson, J. R. Ornamental plants as invasive aliens: Problems and solutions in Kruger National Park, South Africa. Environ. Manag. 41, 32–51 (2008).ADS
Google Scholar
84.Mueller-Dombois, D. & Ellenberg, H. Aims and Methods of Vegetation Ecology (Wiley, 1974).
Google Scholar
85.van der Maarel, E. Transformation of cover-abundance values in phytosociology and its effects on community similarity. Vegetatio 38, 97–114 (1979).
Google Scholar
86.Magurran, A. E. Ecological Diversity and Its Measurement (Croom Helm, 1988).
Google Scholar
87.Pooley, E. Wildflowers of Kwazulu-Natal and the Eastern Region (Natal Flora Publications Trust, 1998).
Google Scholar
88.Schmidt, E., Lötter, M. & McCleland, W. Trees and Shrubs of Mpumalanga and Kruger National Park (Jacana Media, 2002).
Google Scholar
89.van der Walt, R. Wild Flowers of the Limpopo Valley (Retha van der Walt, 2009).
Google Scholar
90.Oudtshoorn, F. V. Guide to Grasses of Southern Africa 3rd edn. (Briza Publications, 2018).
Google Scholar
91.R Development Core Team. R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, Vienna, 2013).
Google Scholar
92.Lenth, R. Emmeans: Estimated Marginal Means, aka Least-Square Means. R package version 1.2.1. https://CRAN.R-project.org/package=emmeans (2018).93.Lepš, J. & Šmilauer, P. Multivariate Analysis of Ecological Data Using CANOCO 5 (Cambridge University Press, 2014).MATH
Google Scholar
94.Dray, S., Legendre, P. & Peres-Neto, P. R. Spatial modelling: A comprehensive framework 562 for principal coordinate analysis of neighbour matrices (PCNM). Ecol. Modell. 196, 483–563 (2006).
Google Scholar
95.Šmilauer, P. & Lepš, J. Multivariate Analysis of Ecological Data Using Canoco 5 2nd edn. (Cambridge University Press, 2014).MATH
Google Scholar More
