the biochemical level (Sinsabaugh and Moorhead, 1994), and are induced by the presence of macromolecular and macrophytic substrates within soils (Nausch et al., 1998). Due to the complex structure of macrophytic tissue, a large quantity of diverse enzymes may be necessary to complete degradation (Eriksson and Wood, 1985; Ljungdahl and Eriksson, 1985). The mineralization of plant matter is governed by the chemical and physical properties of available substrates such as lignin, nitrogen (N), and phosphorus (P) availability (DeBusk and Reddy, 1998; Berg, 2000; Fioretto et al., 2000; Kourtev et al., 2002a & b) as well as other environmental and physicochemical influences. The nature of the many interactions that occur between extracellular enzymes and inducing and repressing environmental components are not well understood and may play a significant role in regulating enzyme activity. Some examples of potentially significant interactions include the polyphenolic inhibition of enzyme complexes as a consequence of lignin degradation. These compounds can, in certain appropriate environmental conditions, become the dominant regulatory mechanisms involved in microbial respiration (McClaughtery and Linkins, 1990; Wetzel, 1993). The addition of N has been shown to retard the decomposition of large molecular weight organic matter by the repression of phenol oxidase (Eriksson et al., 1990; Blanchette 1991; Sinsabaugh et al., 1993; Hammel, 1997; Carreiro et al., 2000) and UV photolysis has been shown to enhance enzyme activities by relieving the inhibition by humic compounds (Wetzel et al., 1995; Boavida and Wetzel, 1998; Wetzel, 2000). As a consequence of these complex interactions, the interpretation of individual enzyme activities as simple responses to environmental substrate concentrations may not serve to adequately predict the actual microbial community response.