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Jordan Marshall




Decomposition plays an integral role in the cycling of organic and inorganic nutrients. The purpose of this study is to compare microbial communities related to rates of decomposition. To establish this possible link, leaf litter from a single location was collected and nine carbon fiber bags were filled with the leaf litter. Three sites in northwest Indiana were identified for this experiment, one control site (which was the origin of the leaf litter) and two experimental sites that differed in environmental characteristics. An initial mass was measured for each bag. From the original leaf litter collection, a microbial sample was collected and a sample of the leaf litter was collected for drying to determine the initial dry mass. The experimental bags were checked biweekly over three months. During each visit, the mass of each bag, soil moisture, soil pH, tree species diversity and richness, and canopy density were measured. During the final visit, a final microbial sample was collected for each bag and analyzed for any changes in microbial species or population densities. DNA was extracted from the microbes and amplified using PCR. Once final PCR products were obtained, the samples were mixed to determine a representative sample of each experimental site; four mixed samples were then sequenced at the University of Chicago via high throughput sequencing. Soil moisture was lower at one of the experimental sites compared to the litter source site. Also, soil pH was lower at the litter originating site compared to the two experimental sites. Canopy cover and leaf mass different between sites. Additionally, wet leaf mass was positively related to soil moisture, which would explain mass increases mid-season. Further analysis is needed to fully understand the relationships between decomposition and microbial communities at these sites.



Decomposition Rate Survey Throughout Indiana Dunes National Lakeshore

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