Print PageThe decomposition of organic matter is an essential ecosystem function; it is vital to nutrient cycling, food web dynamics, and can impact biodiversity at multiple scales. Vertebrate carrion represents an ecological unit within a larger ecosystem and can be considered a resource pulse to the immediate soil, invertebrate, and plant communities. Coupled with decomposition are microbial communities. Microbial assemblages are important for many ecosystem processes. The role of microbes in terrestrial systems has been suggested to be just as important as primary producers; microbes convert decaying organic matter into low molecular organic forms, which can then be used by other organisms. Microbes (i.e., bacteria and fungi) have been documented to initially break down carrion; however, empirical data describing microbial community dynamics on carrion are lacking, even though their role in trophic level interactions and food webs is well appreciated.
The goal of this study was to understand microbial community function throughout the decomposition process of vertebrate carrion in the presence and absence of naturally colonizing invertebrates. Microbial community level physiological profiles (MCLPPs) were determined using phenotype microArray BiologTM EcoPlates. BiologTM EcoPlates have been routinely used to evaluate metabolic profiles of environmental microbial communities as a measure of function diversity.
Results/Conclusions
We used non-metric multidimensional scaling (NMDS) to evaluate differences in MCLPPs between treatments, over decomposition time and in relation to temperature; multi-response permutation procedure (MRPP) was used for testing differences between these variables within the ordination and indicator species analysis complemented MRPP to identify levels of variables important to the ordinations. Based on these multivariate analyses we have identified eight carbon sources that may differentiate among decomposition days or accumulated degree hours (ADH). Additionally, a method for modeling ADH using generalized additive models (GAMs) determined that four carbon sources explained 70.3% of deviance in the data. Overall, we determined distinct functional profiles and indicator carbon sources, which may be predictors of vertebrate carcass decomposition time, and that invertebrate communities can alter microbial functional trajectory during this process.
