Microbial Activity Approximation in Soil and Dynamic of Three Edaphic Enzymes Along the Mapire Floodplain, Venezuela, in Times of High and Low Humidity

The aim of the work was to evaluate the effect of soil moisture, texture and organic matter content on the edaphic microbiological, dehydrogenase, urease and acid phosphatase activity of the Mapire floodplain, State of Anzoátegui, Venezuela, which is located in an igapó. The wetland in question was segmented into three sectors according to the flood condition of each one, namely zone of maximum, medium and minimum flooding. The results suggest that dehydrogenase activity increases with waterlogging time and soil humidity, that the absence of oxygen promotes acid phosphatase activity when samples come from the zone of maximum flooding, that the zones of medium and maximum flooding could constitute suitable environments for the proliferation of anaerobic microbial life, and that acetate consumption reaches the highest values in this last area, which would be linked to methanogenic bacterial activity. Urease and acid phosphatase activity seem to have a positive relationship with organic matter content in the period of low soil humidity. Microbial activity, estimated by fluorescein diacetate hydrolysis, is maximum in the medium flood zone during edaphic low humidity season.