Differences may result in part due to the fact that BIOLOG selects for only a portion of the microbial community (Smalla et al., 1998) while PLFA analysis includes the whole microbial community, regardless of activity. Enzyme activities may provide functional measures with more immediate ecological meaning and hence be more clearly related to shifts in microbial
community composition. Greater focus on relationships between community composition and function may improve
our understanding of soil carbon transformations (Buyer and Drinkwater, 1997; Degens, 1998).