Floristic analysis of semi-arid mountain ecosystems of the Griqualand West centre of plant endemism, Northern Cape, South Africa




Abstract. Van Staden N, Siebert SJ, Cilliers DP, Wilsenach D, Frisby AW. 2020. Floristic analysis of semi-arid mountain ecosystems of the Griqualand West centre of plant endemism, Northern Cape, South Africa. Biodiversitas 21: 1989-2002. The Griqualand West Centre (GWC) is one of 13 centres of plant endemism in South Africa. Despite its unique flora, it remains poorly conserved and studied. A recent study identified an extensive geographical core area for the GWC, but endemic plant species were found to be absent from certain parts within these borders. To address this, we refined the current GWC borders based on an ecological niche model, which predicted that endemic species are restricted to four mountain ranges within GWC. Mountain floras within these refined borders were then floristically compared to assess whether they are hotspots of endemicity. Floristically, the Asteraceae, Fabaceae, Malvaceae, and Poaceae were the dominant plant families. Mountain ecosystems differed from one another at species level, with indicator species explaining the compositional differences. Distribution patterns of indicator species were determined by mean annual precipitation, Ca: Mg ratios, soil pH, cation exchange capacity, iron, and sand content. These environmental factors are possible drivers of niche partitioning, environmental filtering and habitat specialization in each mountain ecosystem. Limestone and banded ironstone habitats were identified as conservation priority areas, since they contained the highest numbers of rare and threatened GWC restricted-range species, of which six were narrow endemics.


Abedi M, Bartelheimer M, Poschlod P. 2013. Aluminium toxic effects on seedling root survival affect plant composition along soil reaction gradients–a case study in dry sandy grasslands. J Veg Sci 24: 1074-1085. DOI: 10.1111/jvs.12016
AGIS. 2007. Land Type Survey.
Alexander B. 2011. Serpentine soils and why they limit plant survival and growth. Fremontia 38-39: 28-31.
Anderson MG. Ferree, CE. 2010. Conserving the stage: climate change and the geophysical underpinnings of species diversity. PLoS One 5: 1-10. DOI: 10.1371/journal.pone.0011554
Bamigboye SO. 2019. Conservation status and threats to endemic plant species of Griqualand West of South Africa. J Plant Dev 26: 117-121. DOI: 110.33628/jpd.32019.33626.33621.33117
Bean WT. Stafford R. Brashares JS. 2012. The effects of small sample size and sample bias on threshold selection and accuracy assessment of species distribution models. Ecography, 35: 250-258. DOI: 10.1111/j.1600-0587.2011.06545.x
Bojórquez-Quintal E. Escalante-Magaña C. Echevarría-Machado I. Martínez-Estévez M. 2017. Aluminum, a friend or foe of higher plants in acid soils. Front Plant Sci 8:1767. DOI: 10.3389/fpls.2017.01767
Boneschans RB. Coetzee MS. Siebert SJ. 2015. A geobotanical investigation of the Koedoesfontein Complex, Vredefort Dome, South Africa. Aust J Bot 63: 324-340. DOI: 10.1071/BT14267
Buitenwerf R. Swemmer AM. Peel MJS. 2011. Long-term dynamics of herbaceous vegetation structure and composition in two African savanna reserves. J Appl Ecol 48: 238-246. DOI: 10.1111/j.1365-2664.2010.01895.x
Burke A. 2001. Classification and ordination of plant communities of the Naukluft Mountains, Namibia. J Veg Sci 12: 53-60. DOI: 10.1111/j.1654-1103.2001.tb02616.x
Burke A. 2019. How important is patch size relative to patch isolation in an arid inselberg landscape? S Afr J Bot 127: 1-11. DOI: 10.1016/j.sajb.2019.08.029
Callen ST. Miller AJ. 2015. Signatures of niche conservatism and niche shift in the North American kudzu (Pueraria montana) invasion. Divers Distrib 21: 853-863. DOI: 10.1111/ddi.12341
Cañadas EM. Fenu G. Peñas J. Lorite J. Mattana E. Bacchetta G. 2014. Hotspots within hotspots: Endemic plant richness, environmental drivers, and implications for conservation. Biol Conserv 170: 282-291. DOI: 10.1016/j.biocon.2013.12.007
Chakraborty A. 2019. Mountains as vulnerable places: a global synthesis of changing mountain systems in the Anthropocene. GeoJournal: 1-20. DOI:
Clements, R K. Baskin JM. Baskin C. 2002. The Comparative Biology of the Two Closely-Related Species Penstemon tenuiflorus Pennell and P. hirsutus (L.) Willd. (Scrophulariaceae, Section Graciles): IV. Effects of Shade, Drought, and Soil Type on Survival and Growth. Castanea 67: 177-187.
Clements R. Sodhi NS. Schilthuizen M. Ng PKL. 2006. Limestone karsts of Southeast Asia: imperiled arks of biodiversity. Bioscience 56: 733-742. DOI: 10.1641/0006-3568(2006)56[733:LKOSAI]2.0.CO;2
Covelo F. Sales F. Silva MMVG. Garcia CA. 2017. Vegetation on limestone versus phyllite soils: a case study in the west Iberian Peninsula. Flora Mediterr 27: 159-173. DOI: 10.7320/FlMedit27.159
Cowling RM. Holmes PM. 1992. Endemism and speciation in a lowland flora from the Cape Floristic Region. Biol J Linn Soc 47:367-383. DOI: 10.1111/j.1095-8312.1992.tb00675.x
Cowling RM. Witkowski ETF. Milewski AV. Newbey KR. 1994. Taxonomic, edaphic and biological aspects of narrow plant endemism on matched sites in mediterranean South Africa and Australia. J Biogeogr 21: 651-664. DOI: 10.2307/2846038
Curtis OE. Stirton CH. Muasya AM. 2013. A conservation and floristic assessment of poorly known species rich quartz–silcrete outcrops within Rûens Shale Renosterveld (Overberg, Western Cape), with taxonomic descriptions of five new species. S Afr J Bot 87: 99-111. DOI: 10.1016/j.sajb.2013.03.017
Diaz S. Cabido M. Casanoves F. 1998. Plant functional traits and environmental filters at a regional scale. J Veg Sci 9: 113-122. DOI: 10.2307/3237229
Do Carmo, FF Jacobi CM. 2016. Diversity and plant trait-soil relationships among rock outcrops in the Brazilian Atlantic rainforest. Plant Soil 403: 7-20. DOI: 10.1007/s11104-015-2735-7
Dufour A. Gadallah F. Wagner HH. Guisan A. Buttler A. 2006. Plant species richness and environmental heterogeneity in a mountain landscape: effects of variability and spatial configuration. Ecography 29: 573-584. DOI: 10.1111/j.0906-7590.2006.04605.x
Dufrêne M. Legendre P. 1997. Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol Monogr 67: 345-366. DOI: 10.1890/0012-9615(1997)067[0345:SAAIST]2.0.CO;2
Elith J. Phillips SJ. Hastie T. Dudík M. Chee YE. Yates CJ. 2011. A statistical explanation of MaxEnt for ecologists. Divers Distrib 17: 43-57. DOI: 10.1111/j.1472-4642.2010.00725.x
Eriksson PG. Altermann W. Hartzer FJ. 2006. The Transvaal Supergroup and its Precursors. In: Johnson MR. Anhauesser CR Thomas RJ. (eds) The Geology of South Africa. Geologocial Society /Council for Geoscience, Johannesburg/ Pretoria.
Escalante T. Rodríguez-Tapia G. Linaje M. Illoldi-Rangel P. González-López R. 2013. Identification of areas of endemism from species distribution models: threshold selection and Nearctic mammals. TIP Rev Esp Cienc Quim Biol 16: 5-17.
Faucon MP. Colinet G. Mahy G. Luhembwe MN. Verbruggen N. Meerts P. 2009. Soil influence on Cu and Co uptake and plant size in the cuprophytes Crepidorhopalon perennis and C. tenuis (Scrophulariaceae) in SC Africa. Plant Soil 317: 201-212. DOI: 10.1007/s11104-008-9801-3
Ferreira FH. 1927. Setlhapiñ nomenclature and uses of the indigenous trees of Griqualand West. Bantu Stud 3:349-356. DOI: 10.1080/02561751.1927.9676218
Fick SE. Hijmans RJ. 2017. WorldClim 2: new 1?km spatial resolution climate surfaces for global land areas. Int J Climatol 37: 4302-4315. DOI: 10.1002/joc.5086
Fischer E. 2004. Scrophulariaceae. In: Kubitzki K. Kadereit J. (eds) Flowering Plants – Dicotyledons: Lamiales The Families and Genera of Vascular Plants VII. Springer, Berlin.
Fourie M. 2019. What can electrical conductivity tell us about our soil?,of%20nutrients%20in%20the%20soil
Franklin J. Keppel G. Webb EL. Seamon JO. Rey SJ. Steadman DW. Wiser SK. Drake DR. 2013. Dispersal limitation, speciation, environmental filtering and niche differentiation influence forest tree communities in West Polynesia. J Biogeogr 40: 988-999. DOI: 10.1111/jbi.12038
Frisby AW. Siebert SJ. Struwig M. Cilliers DP. 2019. Plant endemism in Griqualand West, South Africa. S Afr J Bot 124: 127-137. DOI: 10.1016/j.sajb.2019.03.041
Gaston KJ. 1997. What is rarity? In: Kunin WE. Gaston KJ. (eds) The Biology of Rarity: Causes and consequences of rare—common differences. Vol. 17. Springer Science & Business Media: London.
Gaston KJ. Kunin WE. 1997. Rare-common differences: An overview. In: Kunin WE. Gaston KJ. (eds) The Biology of Rarity: Causes and consequences of rare—common differences. Vol. 17. Springer Science & Business Media: London.
Gibson N. Meissner R. Markey AS. Thompson WA. 2012. Patterns of plant diversity in ironstone ranges in arid south western Australia. J Arid Environ 77:25-31. DOI: 10.1016/j.jaridenv.2011.08.021
Goldin A. 1976. Effects of limestone soils on plant distribution in the Garnet Mountains, Montana. [Disseration]. University of Montana, Missoula. [United States]
Gupta N. Gaurav SS. Kumar A. 2013. Molecular basis of aluminium toxicity in plants: a review. Am J Plant Sci 4: 21-37. DOI: 10.4236/ajps.2013.412A3004
Hammer Ø. Harper DAT Ryan PD. 2001. PAST: Paleontological Statistics software package for education and data analysis. Paleontol. Electron. 4.
Harrison S. Damschen E. Going BM. 2009. Climate gradients, climate change, and special edaphic floras. Northeast Nat 16: 121-130. DOI: 10.1656/045.016.0510
Hoorn C. Mosbrugger V. Mulch A. Antonelli A. 2013. Biodiversity from mountain building. Nat Geosci 6: 154. DOI: 10.1038/ngeo1742
Jacobi CM. Do Carmo FF. 2008. The contribution of ironstone outcrops to plant diversity in the Iron Quadrangle, a threatened Brazilian landscape. Ambio 37: 324-327. DOI: 10.1579/0044-7447(2008)37[324:TCOIOT]2.0.CO;2
Jacobi CM. Do Carmo FF. Vincent RC. Stehmann JR. 2007. Plant communities on ironstone outcrops: a diverse and endangered Brazilian ecosystem. Biodivers Conserv 16: 2185-2200. DOI: 10.1007/s10531-007-9156-8
Keyser N. 1997. Geological Map of the Republic of South Africa and the Kingdoms of Lesotho and Swaziland: Gravity Edition; 1: 1.000. 000. Council for Geoscience: Pretoria.
Kimball SE. Lulow MR. Balazs K. Huxman TE. 2017. Predicting drought tolerance from slope aspect preference in restored plant communities. Ecol. Evol 7: 3123-3131. DOI: 10.1002/ece3.2881
Koch J. Chakraborty S. Li B. Kucera JM. Van Deventer P. Daniell A. Faul C. Man T. Pearson D. Duda B. 2017. Proximal sensor analysis of mine tailings in South Africa: An exploratory study. J Geochem Explor 181:45-57. DOI: 10.1016/j.gexplo.2017.06.020
Koekemoer M. Steyn HM. Bester SP. 2014. Guide to plant families of southern Africa, edition 2. Strelitzia 31. South African National Biodiversity Institute: Pretoria.
Kruckeberg AR. 1969. Soil diversity and the distribution of plants, with examples from western North America. Madroño 20: 129-154.
Lee JA. 1999. The calcicole-calcifuge problem revisited. In: Callow JA. (ed) Advances in Botanical Research Vol. 29. Academic Press, California.
Leitman P. Amorim AM. Sansevero JB. Forzza RC. 2015. Floristic patterns of epiphytes in the Brazilian Atlantic Forest, a biodiversity hotspot. Bot J Linn Soc 179: 587-601. DOI: 10.1111/boj.12342
Li J. Xiong G. Xu W. Xie Z. 2015. Distribution of shrublands in relation to soil and climate in mid-subtropical China. J Plant Ecol 9: 393-401. DOI: 10.1093/jpe/rtv070
Ludwig JC. 1999. The flora of dolomite and limestone barrens in southwestern Virginia. Castanea 64: 209-230.
MacArthur R. Levins R. 1967. The limiting similarity, convergence, and divergence of coexisting species. Am Nat 101: 377-385.
Manish K. 2019. Macro–ecological patterns and drivers of Himalayan plant species diversity and distribution through the ages. Front Biogeogr 11: e38754. DOI: 10.21425/F5FBG38754
Margules CR. Presse, RL. 2000. Systematic conservation planning. Nature 405: 243-253. DOI: 10.1038/35012251
Markey AS. Dillon SJ. 2010. Flora and vegetation of the banded iron formations of the Yilgarn Craton: Gullewa. Conservation Science W Aust 7: 531-556.
Markey AS. Dillon SJ. 2011. Flora and vegetation of the banded iron formations of the Yilgarn Craton: the Johnston Range, Menzies. Conservation Science W Aust 8: 137-161.
Mason HL. 1946. The edaphic factor in narrow endemism. I. The nature of environmental influences. Madroño 8: 209-226.
McCarthy T. Rubidge B. 2005. The story of earth & life: a southern Africa perspective on a 4.6 billion-year journey. Struik: Cape Town.
Meissner R. Wright J. 2010. Flora and vegetation of banded iron formations of the Yilgarn Craton: Barloweerie and Twin Peaks Greenstone Belts. Conservation Science W Aust 7: 557-570.
Millar TR. Heenan PB. Wilton AD. Smissen RD. Breitwieser I. 2017. Spatial distribution of species, genus and phylogenetic endemism in the vascular flora of New Zealand, and implications for conservation. Aust Syst Bot 30: 134-147. DOI: 10.1071/SB16015
Miller BP. Symons DR Barrett MD. 2019. Persistence of rare species depends on rare events: demography, fire response and phenology of two plant species endemic to a semiarid Banded Iron Formation range. Aust J Bot 67: 268-280. DOI: 10.1071/BT18214
Moen HFG. 2006. The Olifantshoek Supergroup. In: Johnson MR. Anhauesser CR. Thomas RJ. (eds) The Geology of South Africa. Geologocial Society /Council for Geoscience, Johannesburg/ Pretoria.
Mostert JWC. 1967. Veld-tipes,-probleme en weidingnavorsing in die Oranje-Vrystaatstreek. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 2: 31-37. DOI: 10.1080/00725560.1967.9648534
Mota GS. Luz GR. Mota NM. Coutinho ES. Veloso MDM. Fernandes GW. Nunes YRF. 2018. Changes in species composition, vegetation structure, and life forms along an altitudinal gradient of rupestrian grasslands in south-eastern Brazil. Flora 238:32-42. DOI: 10.1016/j.flora.2017.03.010
Mota JF. Medina-Cazorla JM. Navarro FB, Pérez-García FJ. Pérez-Latorre A. Sánchez-Gómez P. Torres JA. Benavente A. Blanca G. Gil C. 2008. Dolomite flora of the Baetic ranges glades (South Spain). Flora 203: 359-375. DOI: 10.1016/j.flora.2007.06.006
Mucina L. Rutherford MC. 2006. The vegetation of South Africa, Lesotho and Swaziland. South African National Biodiversity Institute: Pretoria.
Mustart PJ. Cowling RM. Dunne TT. 1994. Reproductive traits of two closely related species-pairs on adjacent, different soil types in South African Fynbos. Vegetatio 111:161-171. DOI: 10.1007/BF00040335
Myers N. Mittermeier RA. Mittermeier CG. Da Fonseca GA. Kent J. 2000. Biodiversity hotspots for conservation priorities. Nature 403: 853- 858. DOI: 10.1038/35002501
Naaf T. Wulf M. 2012. Plant community assembly in temperate forests along gradients of soil fertility and disturbance. Acta Oecol 39: 101-108. DOI: 10.1016/j.actao.2012.01.009
Negrão R. Sampaio-e-Silva T. Kortz AR. Magurran A. Matos DMS. 2017. An endangered tree fern increases beta-diversity at a fine scale in the Atlantic Forest Ecosystem. Flora 234: 1-6. DOI: 10.1016/j.flora.2017.05.020
Negreiros D. Le Stradic S. Fernandes GW. Rennó HC. 2014. CSR analysis of plant functional types in highly diverse tropical grasslands of harsh environments. Plant Ecol 215: 379-388.
Nekola JC. White PS. 1999. The distance decay of similarity in biogeography and ecology. J Biogeogr 26: 867-878. DOI: 10.1046/j.1365-2699.1999.00305.x
Neri AV. Silva WA. Villa PM. Schaefer CEGR. Ferreira-Júnior WG. 2019. Diversity and life-forms of a woody-herbaceous community on the quartzite rocky complexes in the Brazilian Iron Quadrangle. Rev Biol Trop 67: 357-369.
Non-Affiliated Soil Analysis Work Committee. 1990. Handbook of standard soil testing methods for advisory purposes Vol. 160. Soil Science Society of South Africa, Pretoria.
Noroozi J. Talebi A. Doostmohammadi M. Rumpf SB. Linder HP. Schneeweiss GM. 2018. Hotspots within a global biodiversity hotspot-areas of endemism are associated with high mountain ranges. Sci Rep 8:10345. DOI:10.1038/s41598-41018-28504-41599.
Peñas J. Pérez-García FJ. Mota JF. 2005. Patterns of endemic plants and biogeography of the Baetic high mountains (south Spain). Acta Bot Gallica 152: 347-360. DOI: 10.1080/12538078.2005.10515494
Perrigo A. Hoorn, C. Antonelli A. 2019. Why mountains matter for biodiversity. J Biogeogr 1-11. DOI: 10.1111/jbi.13731
Phillips SJ. Anderson RP. Schapire RE. 2006. Maximum entropy modeling of species geographic distributions. Ecol Model 190: 231-259. DOI: 10.1016/j.ecolmodel.2005.03.026
Phillips SJ. Dudík M. Elith J. Graham CH. Lehmann A. Leathwick J. Ferrier S. 2009. Sample selection bias and presence?only distribution models: implications for background and pseudo?absence data. Ecol Appl 19: 181-197. DOI: 10.1890/07-2153.1
Phillips SJ. Dudík M. Schapire RE. 2019. Maxent software for modeling species niches and distributions (Version 3.4.1).
Porembski S. Barthlott W. 2000. Granitic and gneissic outcrops (inselbergs) as centers of diversity for desiccation-tolerant vascular plants. Plant Ecol 151: 19-28. DOI: 10.1023/A:1026565817218
PRIMER 6 version 1.1.15. 2012. PRIMER-E Ltd.
Rajakaruna N. 2004. The edaphic factor in the origin of plant species. Int Geol Rev 46: 471-478. DOI: 10.2747/0020-6814.46.5.471
Rajakaruna N. 2018. Lessons on evolution from the study of edaphic specialization. Bot Rev 84: 39-78. DOI: 10.1007/s12229-017-9193-2
Ranwashe F. 2019. BODATSA: Botanical Collections. v1.4. South African National Biodiversity Institute. Dataset/Occurrence.
Raven PH. 1964. Catastrophic selection and edaphic endemism. Evolution 18: 336-338. DOI: 10.2307/2406409
Roberts DW. 2016. Package ‘labdsv’.
Robinson BH. Brooks RR. Kirkman JH. Gregg PEH. Gremigni P. 1996. Plant?available elements in soils and their influence on the vegetation over ultramafic ("serpentine") rocks in New Zealand. J Roy Soc New Zeal 26: 457-468. DOI:
Robinson TP. Di Virgilio G. Temple-Smith D. Hesford J. Wardell-Johnson GW. 2019. Characterisation of range restriction amongst the rare flora of Banded Ironstone Formation ranges in semiarid south-western Australia. Aust J Bot 67:234-247. DOI: 10.1071/BT18111
Schellenberger Costa D. Gerschlauer F. Pabst H. Kühnel A. Huwe B. Kiese R. Kuzyakov Y. Kleyer M. 2017. Community?weighted means and functional dispersion of plant functional traits along environmental gradients on Mount Kilimanjaro. J Veg Sci 28: 684-695. DOI: 10.1111/jvs.12542
Schmiedel U. Jürgens N. 1999. Community Structure on Unusual Habitat Islands: Quartz-Fields in the Succulent Karoo, South Africa. Plant Ecol 142: 57-69. DOI: 10.1023/A:1009818210799
Schmiedel, U. & Jürgens, N. 2004. Habitat ecology of southern African quartz fields: studies on the thermal properties near the ground. Plant Ecol 170: 153-166. DOI: 10.1023/B:VEGE.0000021661.56381.67
Schober P. Boer C. Schwarte LA. 2018. Correlation coefficients: appropriate use and interpretation. Anesth Analg 126: 1763-1768. DOI: 10.1213/ANE.0000000000002864
Shovon TA. Rozendaal DM. Gagnon D. Gendron F. Vetter M. Vanderwel MC. 2020. Plant communities on nitrogen?rich soil are less sensitive to soil moisture than plant communities on nitrogen?poor soil. J Ecol 108: 133-144. DOI: 10.1111/1365-2745.13251
Siebert F. Siebert SJ. 2005. Dolomitic vegetation of the Sterkfontein Caves World Heritage Site and its importance in the conservation of Rocky Highveld Grassland. Koedoe 48:17-31. DOI: 10.4102/koedoe.v48i1.163
Siebert SJ. Van Wyk AE. Bredenkamp GJ. 2001. Endemism in the flora of ultramafic areas of Sekhukhuneland, South Africa. ?S Afr J Sci 97: 529-532.
Sklená? P. Hedberg I. Cleef AM. 2014. Island biogeography of tropical alpine floras. J Biogeogr 41: 287-297. DOI: 10.1111/jbi.12212
Slatyer C. Rosauer D. Lemckert F. 2007. An assessment of endemism and species richness patterns in the Australian Anura. J Biogeogr 34: 583-596. DOI: 10.1111/j.1365-2699.2006.01647.x
Šmilauer P. Lepš J. 2014. Multivariate Analysis of Ecological Data using CANOCO 5. Cambridge University Press: Cambridge.
Soares MP. Reys P. Pifano DS. De Sá JL. Da Silva PO. Santos TM. Silva FG. 2015. Relationship between edaphic factors and vegetation in savannas of the Brazilian midwest region. Rev Bras Cienc Solo 39: 821-829. DOI: 10.1590/01000683rbcs20130726
South African National Biodiversity Institiute. 2019. Red List of South African plants version 2017.1
Spyreas G. 2016. Scale and sampling effects on floristic quality. PloS One 11: e0160693. DOI: 10.1371/journal.pone.0160693
Stebbins GL. 1942. The genetic approach to problems of rare and endemic species. Madroño 6: 241-258.
Stohlgren TJ. Guenther DA. Evangelista PH. Alley N. 2005. Patterns of plant species richness, rarity, endemism, and uniqueness in an arid landscape. Ecol Appl 15: 715-725. DOI: 10.1890/03-5352
Swadek RK. Burgess TL. 2012. The vascular flora of the north central Texas Walnut Formation. J. Bot. Res. Inst. Texas 6: 725-752.
Taylor-Smith B. Morgan-Richards M. Trewick SA. 2020. Patterns of regional endemism among New Zealand invertebrates. New Zeal J Zool 47: 1-19. DOI: 10.1080/03014223.2019.1681479
Thompson WA. Sheehy NB. 2011. Flora and vegetation of banded iron formations of the Yilgarn Craton: the Montague Range Zone of the Gum Creek Greenstone Belt. Conservation Science W Aust 8: 95-111.
TIBCO Software Inc. 2017. Statistica (data analysis software system) version 13.
Tordoni E. Casolo V. Bacaro G. Martini F. Rossi A. Boscutti F. 2020. Climate and landscape heterogeneity drive spatial pattern of endemic plant diversity within local hotspots in South-Eastern Alps. Perspect Plant Ecol 43: 125512. DOI: 10.1016/j.ppees.2020.125512
Trendall A. 2013. Sedimentary rocks: Banded Iron Formations. In: Elias, SA (ed.) Reference Module in Earth Systems and Environmental Sciences. Elsevier, New York.
Van Coller H. Siebert F. Scogings PF. Ellis S. 2018. Herbaceous responses to herbivory, fire and rainfall variability differ between grasses and forbs. S Afr J Bot 119: 94-103. DOI: 10.1016/j.sajb.2018.08.024
Van Munster S. Magee AR. Zietsman PC. 2019. Deverra rapaletsa (Apiaceae), a new limestone endemic species from the Ghaap Plateau, Northern Cape, South Africa. S Afr J Bot 121: 431-434. DOI: 10.1016/j.sajb.2018.12.005
Van Wyk AE. Smith GF. 2001. Regions of floristic endemism in southern Africa: A review with emphasis on succulents. Umdaus Press: Hatfield.
Wang SW. Boru BH. Njogu AW. Ochola AC. Hu GW. Zhou YD. Wang QF. 2020. Floristic composition and endemism pattern of vascular plants in Ethiopia and Eritrea. J Syst Evol 8: 33-42. DOI: 10.1111/jse.12527
Wild H. Brenan J. Meikle R. Peterson B. Cannon J. 1963. The endemic species of the Chimanimani mountains and their significance. Kirkia 4: 125-157.
Williamson S. Balkwill K. 2015. Plant census and floristic analysis of selected serpentine outcrops of the Barberton Greenstone Belt, Mpumalanga, South Africa. S Afr J Bot 97: 133-142. DOI: 10.1016/j.sajb.2014.12.004
Wilman M. 1946. Preliminary check list of the flowering plants & ferns of Griqualand West (southern Africa). Deighton, Bell & Co. LTD, Cambridge.
Wright IJ. Westoby M. Reich PB. 2002. Convergence towards higher leaf mass per area in dry and nutrient?poor habitats has different consequences for leaf life span. J Ecol 90: 534-543. DOI: 10.1046/j.1365-2745.2002.00689.x
Zhang J. Nielsen SE. Grainger TN. Kohler M. Chipchar T. Farr DR. 2014. Sampling plant diversity and rarity at landscape scales: importance of sampling time in species detectability. PLoS One 9: e95334. DOI: 95310.91371/journal.pone.0095334.
Zhang W. Huang D. Wang R. Liu J. Du N. 2016. Altitudinal patterns of species diversity and phylogenetic diversity across temperate mountain forests of northern China. PLoS One 11: e0159995. DOI: 0159910.0151371/journal.pone.0159995
Zietsman MM. Bredenkamp GJ. 2007. Threatened Limestone Fynbos plant communities of Andrew’s Field and Tsaba-Tsaba Nature Reserve, Western Cape. Bothalia 37: 89-102. DOI: 10.4102/abc.v37i1.306