Fig. 4. Mean percentage of mole fraction (across October 2000 and June 2001 sample dates) of the 19 fatty acid methyl esters (FAMEs) included in the principal component analysis for the five sites in the regional dataset and their placement into the microbial taxonomic groups (bacterial, actinomycetal, fungal, and protozoan). Different letters represent significant differences between sites (p < 0.05).