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USE OF STABLE CARBON ISOTOPE RATIOS OF FATTY ACIDS TO EVALUATE MICROBIAL CARBON SOURCES IN TERRESTRIAL ENVIRONMENTS
Citation:
Burke Jr., R A., M Molina, AND J E. Cox. USE OF STABLE CARBON ISOTOPE RATIOS OF FATTY ACIDS TO EVALUATE MICROBIAL CARBON SOURCES IN TERRESTRIAL ENVIRONMENTS. Presented at Soil Science Society of America Annual Meeting, Salt Lake City, UT, November 1-4, 1999.
Description:
We use measurements of the concentration and stable carbon isotopic ratio (D 13C) of individual microbial phospholipid fatty acids (PLFAs) in soils as indicators of live microbial biomass levels and microbial carbon source. We found that intensive sugar cane cultivation leads to a reduction in total soil PLFA content (a measure of live microbial biomass) relative to the forest soil. Total soil PLFA content does not appear to be reduced by conversion of forest to pasture or to less intensively managed sugar cane cultivation, however. Data from systems which were converted from tropical forest at different times in the past suggest that the soil microbial community more rapidly and/or completely switches over to use of C4 carbon under pasture than under sugar cane cultivation.