Print PageSaprotrophic fungi are responsible for most of the organic matter decomposition in terrestrial ecosystems. Fungi produce a complex suite of extracellular enzymes that are necessary to degrade plant polymers. Degradation of plant litter by these extracellular enzymes is significant to recycling of carbon. By studying enzymes and other traits that correspond with the acquisition of resources that vary across ecosystems, we will be able to examine how saprotrophic fungal communities are assembled. This study was undertaken to evaluate how fungal taxonomic community composition is influenced by a variety of factors. Samples were collected at Manistee National Forest in Michigan, a highly studied site with over 20 years of research. Three ecosystem types were examined: Black Oak/White Oak, Sugar Maple/Basswood, and Sugar Maple/Red Oak. Data was collected at three sites from each ecosystem. Within each site, thirty individual leaves on the forest floor were mapped in place, and then collected. DNA was then extracted from each of these samples. Fungal taxonomic community composition was determined using a molecular finger printing method known as Terminal Restriction Fragment Length Polymorphism (T-RFLP). In addition, abundance of taxonomic groups and functional traits were measured via q-PCR, and plant tissue chemistry was analyzed by chemical extraction.
Results/Conclusions
Q-PCR data of functional gene copy numbers showed a significant difference between the dominant leaf types in Sugar Maple/Red Oak sites. Black Oak/White Oak and Sugar Maple/Basswood sites failed to reveal a similar patterns. Preliminary data show that neutral processes (dispersal limitation) explain more of the microbial community composition variability than does the niche processes (leaf type and biochemistry). Ongoing work is being conducted to analyze functional gene abundance profiles, as well as neutral processes.
