Carbonate Precipitation through Microbial Activity

Carbonate precipitation inthe vadose zone of hot arid to semi-arid regions is enhanced by a decrease in Pqo and / h,o due to increasing temperature and evaporation. Conversely, carbonate leaching is enhanced by a humid climate, which prevents the evaporative concentration of dissolved Ca " " and Mg " ". Loss of water through uptake by plants was argued by Klappa (1980) to be a likely mechanism for the precipitation of carbonates around roots. Carbonate precipitation around roots (rhizocre-tions) may also be enhanced by microbial activities (Krumbein, 1968) and an increase in alkalinity due to the decay of dead plants. 

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