Nutrient inputs and dynamics of the fynbos ecosystem, particularly after a fire, are poorly understood. This article provides chemical analyses of macronutrients (Cl, Na, SO 4 , Mg, Ca and K) in rainwater, stream water, soil and bedrock over a period of one year following a fire event in a coastal mountain sandstone fynbos ecosystem.Rainwater, stream water, soil and bedrock samples were taken from a mountain fynbos area underlain by homogeneous Peninsula Formation sandstone bedrock for a one-year period. Rainwater, stream water and soil saturated paste extracts were analysed for macronutrients using a Dionex DX-120 Ion Chromatograph. Crushed soil and bedrock samples were analysed for major element oxide and S content.Above-ground biomass recovery after one year was modest (5–10% of the 19-year-old pre-fire biomass) with marine aerosols supplying Cl and Na ions to the ecosystem and a significant amount of Mg, SO 4 , Ca and K. Additional Mg, SO 4 , Ca and K are supplied by deposition of local and regional fire ash and dust (mineral aerosols) transported from inland sources mostly by northwesterly winter winds. Nutrient loss diminishes rapidly with the return of pre-fire stream values within 9months after fire, with nutrients gradually replaced through atmospheric deposition rather than the slow weathering bedrock.Macronutrients supplied to the study area reflect seasonal differences with atmospheric processes being the primary source of nutrients to the ecosystem.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.