Drought release and post-drought changes in herbaceous composition and diversity in two land uses subjected to selective bush control in a semi-arid Kalahari savanna

References

• Abbas HA, Bond WJ, Midgley JJ. 2019. The worst drought in 50 years in a South African savannah: limited impact on vegetation. African Journal of Ecology 57: 490–499. https://doi.org/10.1111/aje.12640
   Web of Science ®Google Scholar
• Adler P, Raff D, Lauenroth W. 2001. The effect of grazing on the spatial heterogeneity of vegetation. Oecologia 128: 465–479. https://doi.org/10.1007/s004420100737
   PubMed Web of Science ®Google Scholar
• Archer S, Schimel DS, Holland EA. 1995. Mechanisms of shrubland expansion: land use, climate or CO2? Climatic Change 29: 91–99. https://doi.org/10.1007/BF01091640
   Web of Science ®Google Scholar
• Birnie RV, Tucker G, Fasham M. 2005. General habitat survey and monitoring methods. In Hill D, Fasham M, Tucker G, Shewry M, Shaw P (eds), Handbook of biodiversity methods: survey, evaluation and monitoring. Cambridge: Cambridge University Press. pp. 154–194. https://doi.org/10.1017/CBO9780511542084.007
   Google Scholar
• Bradshaw A. 1997. Restoration of mined lands: using natural processes. Ecological Engineering 8: 255–269. https://doi.org/10.1016/S0925-8574(97)00022-0
   Web of Science ®Google Scholar
• Bromilow C. 2010. Problem plants and alien weeds of South Africa. Pretoria: Briza.
   Google Scholar
• Buitenwerf R, Swemmer AM, Peel, MJS. 2011. Long-term dynamics of herbaceous vegetation structure and composition in two African savanna reserves. Journal of Applied Ecology 48: 238–246. https://doi.org/10.1111/j.1365-2664.2010.01895.x
   Web of Science ®Google Scholar
• CABI. 2022. Senna italica (Senegal senna). Available at: https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.11442 [accessed 27 September 2022].
   Google Scholar
• Castillioni K, Wilcox K, Jiang L, Luo Y, Jung CG, Souza L. 2020. Drought mildly reduces plant dominance in a temperate prairie ecosystem across years. Ecology and Evolution 10: 6702–6713. https://doi.org/10.1002/ece3.6400
   PubMed Web of Science ®Google Scholar
• Corby H. 1988. Types of rhizobial nodules and their distribution among the Leguminosae. Kirkia 13: 53–123.
   Google Scholar
• Cornelissen JHC, Lavorel S, Garnier E, Díaz S, Buchmann N, Gurvich DE, Reich PB, Steege H, Morgan HD, Heijden MGA, et al. 2003. A handbook of protocols for standardised and easy measurement of plant functional traits worldwide. Australian Journal of Botany 51: 335–380. https://doi.org/10.1071/BT02124
   Web of Science ®Google Scholar
• Donaldson C. 1966. Control of blackthorn in the Molopo area with special reference to fire. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 1: 57–62. https://doi.org/10.1080/00725560.1966.9648520
   Google Scholar
• Donaldson CH, Kelk DM. 1970. An investigation of the veld problems of the Molopo area: I. Early findings. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 5: 50–57. https://doi.org/10.1080/00725560.1970.9648610
   Google Scholar
• Dong K, He X, Cadotte MW, Xu Y, Jiang M, Hao G, Wang J, Chen L, Ren A, Zhao N, et al. 2022. Soil nutrients mediate the indirect effects of shrub canopy removal: how distance from shrubs affects the herbs and grasses community in a shrub-encroached grassland. Land Degradation & Development 33: 3472–3483. https://doi.org/10.1002/ldr.4400
   Web of Science ®Google Scholar
• Drysdale R, Bob U, Moshabela M. 2021. Socio-economic determinants of increasing household food insecurity during and after a drought in the district of iLembe, South Africa. Ecology of Food and Nutrition 60: 25–43. https://doi.org/10.1080/03670244.2020.1783663
   PubMed Web of Science ®Google Scholar
• Dufrêne M, Legendre P. 1997. Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecological Monographs 67: 345–366. https://doi.org/10.2307/2963459
   Web of Science ®Google Scholar
• Eldridge DJ, Ding J. 2021. Remove or retain: ecosystem effects of woody encroachment and removal are linked to plant structural and functional traits. New Phytologist 229: 2637–2646. https://doi.org/10.1111/nph.17045
   PubMed Web of Science ®Google Scholar
• Ellis EC, Antill EC, Kreft H. 2012. All is not loss: plant biodiversity in the Anthropocene. PloS ONE 7: 1–9. https://doi.org/10.1371/journal.pone.0030535
   Web of Science ®Google Scholar
• Fouché HC, Van der Westhuizen HC, Avenant PL. 2014. Grasses of the Kalahari vegetation types. Upington: KLK Landbou.
   Google Scholar
• Germishuizen G, Meyer NL. 2003. Plants of southern Africa: an annotated checklist. Strelitzia 14. Pretoria: National Botanical Institute.
   Google Scholar
• Gil-Romera G. Lamb HF, Turton D, Sevilla-Callejo M, Umer M. 2010. Long-term resilience, bush encroachment patterns and local knowledge in a Northeast African savanna. Global Environmental Change 20: 612–626. https://doi.org/10.1016/j.gloenvcha.2010.04.008
   Web of Science ®Google Scholar
• Grime JP. 1973. Competitive exclusion in herbaceous vegetation. Nature 242: 344–347. https://doi.org/10.1038/242344a0
   Web of Science ®Google Scholar
• Grime JP. 1977. Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory. American Naturalist 111: 1169–1194. https://doi.org/10.1086/283244
   Web of Science ®Google Scholar
• Hagos MG, Smit GN. 2005. Soil enrichment by Acacia mellifera subsp. detinens on nutrient poor sandy soil in a semi-arid southern African savanna. Journal of Arid Environments 61: 47–59. https://doi.org/10.1016/j.jaridenv.2004.08.003
   Web of Science ®Google Scholar
• Hammer Ø, Harper DAT, Ryan PD. 2001. PAST: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4: 1–9.
   Google Scholar
• Harmse CJ, Kellner K, Dreber N. 2016. Restoring productive rangelands: a comparative assessment of selective and non-selective chemical bush control in a semi-arid Kalahari savanna. Journal of Arid Environments 135: 39–49. https://doi.org/10.1016/j.jaridenv.2016.08.009
   Web of Science ®Google Scholar
• Hofer D, Suter M, Buchmann N, Lüscher A. 2017. Nitrogen status of functionally different forage species explains resistance to severe drought and post-drought overcompensation. Agriculture, Ecosystems & Environment 236: 312–322. https://doi.org/10.1016/j.agee.2016.11.022
   Web of Science ®Google Scholar
• Huntley BJ, Walker BH. 1982. Ecology of tropical savannas. Berlin: Springer. https://doi.org/10.1007/978-3-642-68786-0
   Google Scholar
• Huston M. 1979. A general hypothesis of species diversity. The American Naturalist 113: 81–101. https://doi.org/10.1086/283366
   Web of Science ®Google Scholar
• Hutley LB, Setterfield SA. 2019. Savanna. Encyclopedia of Ecology. Elsevier. pp 623–633. https://doi.org/10.1016/B978-0-12-409548-9.11148-0
   Google Scholar
• Jacobs SM, Naiman RJ. 2008. Large African herbivores decrease herbaceous plant biomass while increasing plant species richness in a semi-arid savanna toposequence. Journal of Arid Environments 72: 891–903. https://doi.org/10.1016/j.jaridenv.2007.11.015
   Web of Science ®Google Scholar
• Jankauskas B, Jankauskienė G, Fullen MA. 2008. Soil erosion and changes in the physical properties of Lithuanian Eutric Albeluvisols under different land use systems. Acta Agriculturae Scandinavica Section B – Soil and Plant Science 58: 66–76. https://doi.org/10.1080/09064710701214379
   Google Scholar
• Kellner K, Fouché J, Tongway D, Boneschans R, van Coller H, van Staden N. 2022. Landscape Function Analysis: responses to bush encroachment in a semi-arid savanna in the Molopo region, South Africa. Sustainability (Basel) 14: 8616. https://doi.org/10.3390/su14148616
   Web of Science ®Google Scholar
• Kgosikoma OE, Mojeremane W, Harvie BA. 2013. Grazing management systems and their effects on savanna ecosystem dynamics: a review. Journal of Ecology and the Natural Environment 5: 88–94. https://doi.org/10.5897/JENE2013.0364
   Google Scholar
• Lawal S, Lennard C, Hewitson B. 2019. Response of Southern African vegetation to climate change at 1.5 and 2.0 global warming above the pre-industrial level. Climate Services 16: 100134. https://doi.org/10.1016/j.cliser.2019.100134
   Google Scholar
• Levins R. 1968. Evolution in changing environments. Princeton: Princeton University Press. https://doi.org/10.1515/9780691209418
   Google Scholar
• Leys JF. 1991. Towards a better model of the effect of prostrate vegetation cover on wind erosion. Vegetatio 91: 49–58. https://doi.org/10.1007/BF00036047
   Google Scholar
• Lucci GM. 2019. Pastures and drought: a review of processes and implications for nitrogen and phosphorus cycling in grassland systems. Soil Research 57: 101–112. https://doi.org/10.1071/SR18079
   Web of Science ®Google Scholar
• Mangani T, Marquart A, Chirima G, Kellner K. 2022. Grass species diversity response to brush packing in semi-arid rangelands of South Africa. Journal of Arid Environments 207: 104832. https://doi.org/10.1016/j.jaridenv.2022.104832
   Web of Science ®Google Scholar
• Marquart A, van Coller H, van Staden N, Kellner K. 2023. Impacts of selective bush control on herbaceous diversity in wildlife and cattle land use areas in a semi-arid Kalahari savanna. Journal of Arid Environments 208: 104881. https://doi.org/10.1016/j.jaridenv.2022.104881
   Web of Science ®Google Scholar
• Mbokodo I, Bopape MJ, Chikoore H, Engelbrecht F, Nethengwe N. 2020. Heatwaves in the future warmer climate of South Africa. Atmosphere (Basel) 11: 712. https://doi.org/10.3390/atmos11070712
   Web of Science ®Google Scholar
• Mishra AK, Singh VP. 2010. A review of drought concepts. Journal of Hydrology 391: 202–216. https://doi.org/10.1016/j.jhydrol.2010.07.012
   Web of Science ®Google Scholar
• Mosalagae D, Mogotsi K. 2013. Caught in a sandstorm: an assessment of pressures on communal pastoral livelihoods in the Kalahari Desert of Botswana. Pastoralism: Research, Policy and Practice 3: 18–20. https://doi.org/10.1186/2041-7136-3-18
   Google Scholar
• Moshobane MC, Esser LF. 2022. Ensemble modeling for the potential distribution of invasive weed Verbesina encelioides in South Africa from 2020 to 2090. Mangement of Biological Invasions 13: 833–844. https://doi.org/10.3391/mbi.2022.13.4.16
   Web of Science ®Google Scholar
• Munjonji L, Ayisi KK, Mudongo EI, Mafeo TP, Behn K, Mokoka MV, Linstädter A. 2020. Disentangling drought and grazing effects on soil carbon stocks and CO2 fluxes in a semi-arid African savanna. Frontiers in Environmental Science 8: 590665. https://www.frontiersin.org/articles/10.3389fenvs.2020.590665
   Web of Science ®Google Scholar
• O’Connor TG. 1991. Local extinction in perennial grasslands: a life-history approach. The American Naturalist 137: 753–773. https://doi.org/10.1086/285192
   Web of Science ®Google Scholar
• O’Connor TG. 1995. Transformation of a savanna grassland by drought and grazing. African Journal of Range & Forage Science 12: 53–60. https://doi.org/10.1080/10220119.1995.9647864
   Google Scholar
• O’Connor TG, Puttick JR, Hoffman MT 2014. Bush encroachment in southern Africa: changes and causes. African Journal of Range & Forage Science. 31:67-88. https://doi.org/10.2989/10220119.2014.939996
   Web of Science ®Google Scholar
• Odadi WO, Young TP, Okeyo-Owuor J. 2007. Effects of wildlife on cattle diets in Laikipia rangeland, Kenya. Rangeland Ecology & Management 60: 179–185. https://doi.org/10.2111/05-044R3.1
   Web of Science ®Google Scholar
• Oksanen J, Blanchet FG, Kindt R, Legendre P, Minchin PR, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Wagner H. 2019. Vegan: community ecology package. Version 2.4–4. https://cran.r-project.org/web/packages/vegan/index.html [Accessed 15 February 2022]
   Google Scholar
• Osborne CP, Charles-Dominique T, Stevens N, Bond WJ, Midgley G, Lehmann CE. 2018. Human impacts in African savannas are mediated by plant functional traits. New Phytologist 220: 10–24. https://doi.org/10.1111/nph.15236
   PubMed Web of Science ®Google Scholar
• Pausas JG, Lamont BB, Paula S, Appezzato-da-Glória B. Fidelis A. 2018. Unearthing belowground bud banks in fire-prone ecosystems. New Phytologist 217: 1435–1448. https://doi.org/10.1111/nph.14982
   PubMed Web of Science ®Google Scholar
• Pedrol N, Souza-Alonso P, Puig CG, González L, Covelo EF, Asensio V, Forján R, Andrade L. 2014. Improving soil fertility to support grass-legume revegetation on lignite mine spoils. Communications in Soil Science and Plant Analysis 45: 1565–1582. https://doi.org/10.1080/00103624.2013.875203
   Web of Science ®Google Scholar
• PRIMER 6 version 1.1.15. 2012. PRIMER-E Ltd. https://www.primer-e.com [Accessed 7 July 2022]
   Google Scholar
• Püttker T, de Arruda Bueno A, Prado PI, Pardini R. 2015. Ecological filtering or random extinction? Beta-diversity patterns and the importance of niche-based and neutral processes following habitat loss. Oikos 124: 206–215. https://doi.org/10.1111/oik.01018
   Web of Science ®Google Scholar
• R Core Team. 2020. R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing. https://www.R-project.org [Accessed 15 February 2022]
   Google Scholar
• Reed MS, Stringer LC, Dougill AJ, Perkins JS, Atlhopheng JR, Mulale K, Favretto N. 2015. Reorienting land degradation towards sustainable land management: linking sustainable livelihoods with ecosystem services in rangeland systems. Journal of Environmental Management 151: 472–485. https://doi.org/10.1016/j.jenvman.2014.11.010
   PubMed Web of Science ®Google Scholar
• Rich R, Hack V, McMeechan F. 2005. Chapter 15: Vascular plants. In Hill D, Fasham M, Tucker G, Shewry M, Shaw P (eds), Handbook of biodiversity methods: survey, evaluation and monitoring. Cambridge: Cambridge University Press. pp. 303–321. https://doi.org/10.1017/CBO9780511542084.016
   Google Scholar
• Riginos C, Porensky LM, Veblen KE, Young TP. 2018. Herbivory and drought generate short-term stochasticity and long-term stability in a savanna understory community. Ecological Applications 28: 323–335. https://doi.org/10.1002/eap.1649
   PubMed Web of Science ®Google Scholar
• Ruppert JC, Harmoney K, Henkin Z, Snyman HA, Sternberg M, Willms W, Linstädter A. 2015. Quantifying drylands’ drought resistance and recovery: the importance of drought intensity, dominant life history and grazing regime. Global Change Biology 21: 1258–1270. https://doi.org/10.1111/gcb.12777
   PubMed Web of Science ®Google Scholar
• Rutherford MC, Mucina L, Lötter MC, Bredenkamp GJ, Smit JHL, Scott-Shaw CR, Hoare DB, Goodman PS, Bezuidenhout H, Scott L, et al. 2006. Savanna Biome. In Mucina L, Rutherford MC (eds), The vegetation of South Africa, Lesotho and Swaziland. Pretoria: SANBI. pp. 438–539.
   Google Scholar
• Schmiedel U, Jacke V, Hachfeld B, Oldeland J. 2021. Response of Kalahari vegetation to seasonal climate and herbivory: results of 15 years of vegetation monitoring. Journal of Vegetation Science 32: e12927. https://doi.org/10.1111/jvs12927
   Web of Science ®Google Scholar
• Siebert F, Scogings P. 2015. Browsing intensity of herbaceous forbs across a semi-arid savanna catenal sequence. South African Journal of Botany 100: 69–74. https://doi.org/10.1016/j.sajb.2015.05.007
   Web of Science ®Google Scholar
• Siebert F, Klem J, van Coller H. 2020a. Forb community responses to an extensive drought in two contrasting land-use types of a semi-arid Lowveld savanna. African Journal of Range & Forage Science 37: 53–64. https://doi.org/10.2989/10220119.2020.1726464
   Web of Science ®Google Scholar
• Siebert F, van Staden N, Komape DM, Swemmer AM, Siebert SJ. 2020b. Effects of land-use change on herbaceous vegetation in a semi-arid Mopaneveld savanna. Bothalia 51: a8.
   Web of Science ®Google Scholar
• Smit GN. 2005. Tree thinning as an option to increase herbaceous yield of an encroached semi-arid savanna in South Africa. BMC Ecology 5: 4–15. https://doi.org/10.1186/1472-6785-5-4
   PubMedGoogle Scholar
• Skarpe C. 1992. Dynamics of savanna ecosystems. Journal of Vegetation Science 3: 293–300.
   Web of Science ®Google Scholar
• Skarpe C, Hester AJ. 2008. Plant traits, browsing and gazing herbivores, and vegetation dynamics. In: Gordon IJ, Prins HHT (eds), The ecology of browsing and grazing. Springer: Heidelberg. pp. 217–261. https://doi.org/10.1007/978-3-540-72422-3_9
   Google Scholar
• Sprent JI, Ardley JK, James EK. 2013. From North to South: a latitudinal look at legume nodulation processes. South African Journal of Botany 89: 31–41. https://doi.org/10.1016/j.sajb.2013.06.011
   Web of Science ®Google Scholar
• Stafford W, Birch C, Etter H, Blanchard R, Mudavanhu S, Angelstam P, Blignaut J, Ferreira L, Marais C. 2017. The economics of landscape restoration: benefits of controlling bush encroachment and invasive plant species in South Africa and Namibia. Ecosystem Services 27: 193–202. https://doi.org/10.1016/j.ecoser.2016.11.021
   Web of Science ®Google Scholar
• Swemmer AM, Bond WJ, Donaldson J, Hempson GP, Malherbe J, Smit IP. 2018. The ecology of drought: a workshop report. South African Journal of Science 114: 1–3. https://doi.org/10.17159/sajs.2018/5098
   Web of Science ®Google Scholar
• Taylor A, Lindsey P A, Davies-Mostert H, Goodman P. 2016. An assessment of the economic, social and conservation value of the wildlife ranching industry and its potential to support the green economy in South Africa (Green Economy Research Report). Johannesburg: The Endangered Wildlife Trust. pp. 96–109.
   Google Scholar
• Trytsman M, Masemola EL, Müller FL, Calitz FJ, van Wyk AE. 2019. Assessing legumes indigenous to South Africa, Lesotho and Swaziland for their pasture potential. African Journal of Range & Forage Science 36: 27–40. https://doi.org/10.2989/10220119.2018.1522515
   Web of Science ®Google Scholar
• van Aardt AC, Codron D, Theron EJ, du Preez PJ. 2020. Plant community structure and possible vegetation changes after drought on a granite catena in the Kruger National Park, South Africa. Koedoe: African Protected Area Conservation and Science 62: 1–11. https://doi.org/10.4102/koedoe.v62i2.1585
   Google Scholar
• van Coller H, Klem J, Siebert F. 2021. Drought tolerant forb flora of a semi-arid protected savanna in the Lowveld of South Africa. Bothalia-African Biodiversity & Conservation 51: 1–6. https://doi.org/10.38201/btha.abc.v51.i1.10
   Google Scholar
• van Coller H, Siebert F, Scogings PF, Ellis S. 2018. Herbaceous responses to herbivory, fire and rainfall variability differ between grasses and forbs. South African Journal of Botany 119: 94–103. https://doi.org/10.1016/j.sajb.2018.08.024
   Web of Science ®Google Scholar
• van Oudtshoorn F. 2009. Guide to grasses of Southern Africa. Pretoria: Briza.
   Google Scholar
• Vandermeer JH. 1970. The community matrix and the number of species in a community. The American Naturalist 104: 73–83. https://doi.org/10.1086/282641
   PubMedGoogle Scholar
• Veenendaal E, Ernst W, Modise G. 1996. Effect of seasonal rainfall pattern on seedling emergence and establishment of grasses in a savanna in south-eastern Botswana. Journal of Arid Environments 32: 305–317. https://doi.org/10.1006/jare.1996.0025
   Web of Science ®Google Scholar
• Verlinden M, van Kerkhove A, Nijs I. 2013. Effects of experimental climate warming and associated soil drought on the competition between three highly invasive West European alien plant species and native counterparts. Plant Ecology 214: 243–254. https://doi.org/10.1007/s11258-012-0163-9
   Web of Science ®Google Scholar
• Walker BH, Emslie RH, Owen-Smith RN, Scholes RJ. 1987. To cull or not to cull: lessons from a southern African drought. Journal of Applied Ecology 24: 381–401. https://doi.org/10.2307/2403882
   Web of Science ®Google Scholar
• Wigley-Coetsee C, Staver AC. 2020. Grass community responses to drought in an African savanna. African Journal of Range & Forage Science 37: 43–52. https://doi.org/10.2989/10220119.2020.1716072
   Web of Science ®Google Scholar