The total amount of EL-FAME extracted was used as an index of total biomass. The sum of EL-FAMEs characteristic to general bacteria, Gram positive (Gm+) bacteria, Gram negative bacteria (Gm−), actinomycetes, saprotrophic fungi, and protozoans were used to identify these taxonomic groups. The total of 16:1ω5c, the marker for abruscular mycorrhizal fungi (AMF), cannot be used directly as indicative of the total population, since this EL-FAME also occurs in bacteria. Therefore, the AMF data was based on the ratio of 16:1ω5c to total bacterial EL-FAMEs (Moore-Kucera and Dick 2008). The ratio of total fungal to total bacterial EL-FAMEs was calculated. Physiological or nutritional stress markers were calculated as follows: total monounsaturated to total saturated EL-FAMEs, and the sum of cyclopropyl EL-FAMEs to the sum of their monounsaturated precursors (Moore-Kucera and Dick 2008).