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Dust as a Nutrient Source for Fynbos Ecosystems, South Africa

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Abstract

Fynbos is the main vegetation of the Cape Floristic Region, a biodiversity hotspot that occurs in southwestern South Africa. A major question concerning the fynbos ecosystem is how it supports abundant and diverse vegetation on soils derived from nutrient-poor bedrock. In addition to marine aerosols (recycled sea salts), geochemical analyses reported here suggest that dust (aeolian) deposition represents a significant source of nutrients (for example, K, Ca and Zn) to the fynbos ecosystem. Headwater portions of the Boontjies River sub-catchment near the Cederberg Mountains support mountain fynbos communities that are entirely underlain by the Peninsula Formation, a quartz arenite with greater than 98 wt% SiO2. Fynbos soils in these areas are composed of quartzose sand with 3–6 wt% kaolinitic clay and 1–2 wt% organic carbon. The minor amount of feldspar and mica minerals in the bedrock (0.5 wt% Al2O3) suggests an aeolian source for much of the clay minerals in the soil. The isotope composition of soluble Pb and Sr from fynbos vegetation and soils indicates a mixture of anthropogenic and terrigenous sources, most likely from washout of combusted petrol and dust from the arid interior particularly in association with Berg Wind events. Approximate mass balance calculations indicate that washout of aerosols provides an important source of nutrients such as Ca, K, P, Fe, Mn and Zn which the fynbos ecosystem is highly effective in retaining.

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References

  • Alleman LY, Church TM, Véron AJ, Kim G, Hamelin B. 2001. Isotopic evidence of contaminant lead in the South Atlantic troposphere and surface waters. Deep Sea Res Part II Trop Stud Oceanogr 48(13):2811–27

    Article  CAS  Google Scholar 

  • Billmark KA, Swap RA, Macko SA. 2005. Stable isotope and GC/MS characterization of southern African aerosols. S Afr J Sci 101(3&4):177–9

    CAS  Google Scholar 

  • Bollhöfer A, Rosman KJR. 2000. Isotopic source signatures for atmospheric lead: the southern hemisphere. Geochim Cosmochim Acta 64(19):3251–62

    Article  Google Scholar 

  • Brown G, Mitchell DT, Stock WD. 1984. Atmospheric deposition of phosphorus in a coastal fynbos ecosystem of the Southwestern Cape, South-Africa. J Ecol 72(2):547–51

    Article  CAS  Google Scholar 

  • Brown JS. 1962. Ore leads and isotopes. Econ Geol 57:673–720

    Article  CAS  Google Scholar 

  • Campbell BM. 1983. Montane plant environments in the fynbos biome. Bothalia 14:283–98

    CAS  Google Scholar 

  • City of Cape Town. 2002. Air Pollution Episodes—2002. City of Cape Town Air Quality Monitoring Network

  • Dia A, Chauvel C, Bulourde M, Gerard M. 2006. Eolian contribution to soils on Mount Cameroon: isotopic and trace element records. Chem Geol 226(3–4):232–52

    Article  CAS  Google Scholar 

  • Eckardt FD, Spiro B. 1999. The origin of sulphur in gypsum and dissolved sulphate in the central Namib Desert, Namibia. Sediment Geol 123(3–4):255–73

    Article  CAS  Google Scholar 

  • Faure G. 1986. Principles of isotope geology. New York: Wiley

    Google Scholar 

  • Garlick G. 1999. Origin and structural development of the Table Mountain Group quartzite aquifer with respect to its hydrogeology, Citrusdal area, Western Cape [Hon Thesis]. Cape Town: University of Cape Town

  • Goldblatt P, Manning J. 2002. Plant diversity of the Cape Region of South Africa. Ann Mo Bot Gard 89:281–302

    Article  Google Scholar 

  • Govender S. 2002. Lead concentration and isotopic composition by mass spectrometry and their implication for anthropogenic components at farms in Philippi, Western Cape—a pilot study [B Tech]. Cape Town: Cape Technikon

    Google Scholar 

  • Grousset FE, Biscaye PE. 2005. Tracing dust sources and transport patterns using Sr, Nd and Pb isotopes. Chem Geol 222(3):149–67

    Article  CAS  Google Scholar 

  • Hartnady CJH, Hay ER. 2002. Bosckloof groundwater discovery. In: Pietersen K, Parsons R, Eds. A synthesis of the hydrogeology of the Table Mountain Group—Formation of a Research Strategy. Pretoria: Water Research Commission. pp 168–77

    Google Scholar 

  • Hay ER, Hartnady CJH. 2002. Towards “Map-Centric” simulation modelling of Table Mountain Group Recharge. In: Pietersen K, Parsons R, Eds. A synthesis of the hydrogeology of the Table Mountain Group—Formation of a Research Strategy. Pretoria: Water Research Commission. pp 103–7

    Google Scholar 

  • Kurtz AC, Derry LA, Chadwick OA. 2001. Accretion of Asian dust to Hawaiian soils; isotopic, elemental, and mineral mass balances. Geochim Cosmochim Acta 65(12):1971–83

    Article  CAS  Google Scholar 

  • Margui E, Iglesias M, Queralt I, Hidalgo M. 2006. Lead isotope ratio measurements by ICP-QMS to identify metal accumulation in vegetation specimens growing in mining environments. Sci Total Environ 367(2–3):988–98

    PubMed  CAS  Google Scholar 

  • Martin JH, Fitzwater SE. 1988. Iron-deficiency limits phytoplankton growth in the northeast Pacific subarctic. Nature 331(6154):341–3

    Article  CAS  Google Scholar 

  • Meyer PS. 2002. Springs in the Table Mountain Group, with special reference to fault controlled springs. In: Pietersen K, Parsons R, Eds. A synthesis of the hydrogeology of the Table Mountain Group—Formation of a Research Strategy. Pretoria: Water Research Commission. pp 224–5

    Google Scholar 

  • Monastra V, Derry LA, Chadwick OA. 2004. Multiple sources of lead in soils from a Hawaiian chronosequence. Chem Geol 209(3–4):215–31

    Article  CAS  Google Scholar 

  • Myers N, Mittermeier RA, Mittermeier CG, da Fonseca GAB, Kent J. 2000. Biodiversity hotspots for conservation priorities. Nature 403:853–8

    Article  PubMed  CAS  Google Scholar 

  • Nelson DW, Sommers LE. 1982. Total carbon, organic carbon and organic matter. In: Page AL, Miller RH, Keeney DR, Eds. Methods of soil analysis: Part 2, chemical and microbiological properties. 2nd edn. Madison: Soil Science Society of America

  • Piketh SJ, Swap RJ, Maenhaut W, Annegarn HJ, Formenti P. 2002. Chemical evidence of long-range atmospheric transport over southern Africa. J Geophys Res 107(D24):4817

    Article  CAS  Google Scholar 

  • Porder S, Clark DA, Vitousek PM. 2006. Persistence of rock-derived nutrients in the wet tropical forests of La Selva, Costa Rica. Ecology 83(3):594–602

    Article  Google Scholar 

  • Reynolds R, Neff J, Reheis M, Lamothe P. 2006. Atmospheric dust in modern soil on aeolian sandstone, Colorado Plateau (USA): variation with landscape position and contribution to potential plant nutrients. Geoderma 130:108–23

    Article  CAS  Google Scholar 

  • Rhoades JD. 1982. Soluble salts. In: Page AL, Miller RH, Keeney DR, Eds. Methods of soil analysis: Part 2, chemical and microbiological properties. 2nd edn. Madison: Soil Science Society of America

  • Rutherford MC. 1978. Karoo-fynbos biomass along an elevational gradient in the Western Cape. Bothalia 12(3):555–60

    Google Scholar 

  • Smit A. 2003. Geochemistry of a pristine fynbos ecosystem in the Harold Porter National Botanical Gardens and Kogelberg Biosphere Reserve [MSc]. Cape Town: University of Cape Town

  • Soderberg K. 2003. Geochemistry of the fynbos ecosystem in a Table Mountain Group sub-catchment of the Olifants River, Western Cape, South Africa [MSc]. Cape Town: University of Cape Town

  • Stock WD, Allsopp N. 1992. Functional perspective of ecosystems. In: Cowling RM, Ed. The ecology of fynbos, nutrients, fire and diversity. Cape Town: Oxford University Press. pp 241–59

    Google Scholar 

  • Sugawara K. 1967. Migration of elements through phases of the hydrosphere and atmosphere. In: Vinogradov AP, Ed. Chemistry of the Earth’s crust. Jerusalem: Israel Program for Scientific Translation Ltd. pp 227–37

    Google Scholar 

  • Swap R, Garstang M, Greco S. 1992. Saharan dust in the Amazon Basin. Tellus B 44(2):133–49

    Article  Google Scholar 

  • Swap R, Garstang M, Macko SA, Tyson PD, Maenhaut W, Artaxo P, Kallberg P, Talbot R. 1996. The long-range transport of southern African aerosols to the tropical South Atlantic. J Geophys Res 101(D19):23777–91

    Article  CAS  Google Scholar 

  • Taylor HC. 1996. Cederberg vegetation and flora. Pretoria: National Botanical Insitute

    Google Scholar 

  • Van de Velde K, Vallelonga P, Candelone JP, Rosman KJR, Gaspari V, Cozzi G, Barbante C, Udisti R, Cescon P, Boutron CF. 2005. Pb isotope record over one century in snow from Victoria Land, Antarctica. Earth Planet Sci Lett 232(1–2):95–108

    Article  CAS  Google Scholar 

  • van Wilgen BW, le Maitre DC. 1981. Preliminary estimates of nutrient levels in fynbos Vegetation and the role of fire in nutrient cycling. S Afr For J 119:24–8

    Google Scholar 

  • van Wyk DB, Lesch W, Stock WD. 1992. Fire and catchment chemical budgets. In: van Wilgen BM, Richardson DM, Kruger FJ, van Hensbergen HJ, Eds. Fire in South African Mountain Fynbos: Ecosystem, Community and Species Response at Swartboskloof. Berlin: Springer. pp 240–57

    Google Scholar 

  • Willis JP. 1999. Instrumental parameters and data quality for routine major and trace element determinations by WDXRFS. Cape Town: Department of Geological Sciences Information Circular University of Cape Town

    Google Scholar 

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ACKNOWLEDGMENTS

We thank the National Research Foundation and the University of Cape Town for financial support of this project. We are also grateful to Shireen Govender for use of her Pb isotope data, to Claudia Neubert for help with the vegetation and soil sampled in 2004, and to numerous colleagues, as well as two anonymous reviewers, for their helpful comments.

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Correspondence to Keir Soderberg.

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Soderberg, K., Compton, J.S. Dust as a Nutrient Source for Fynbos Ecosystems, South Africa. Ecosystems 10, 550–561 (2007). https://doi.org/10.1007/s10021-007-9032-0

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