Pathways and Patterns of Plant Chemistry During Decomposition
Patrick Susman ’17, Stephen Peters-Collaer ’17, and Lynn Christenson (Biology)
Plant litter decomposition changes the way that biogeochemical processes function, and its study is essential to understanding the way that ecosystem nutrient cycling occurs. Numerous studies have investigated decomposition using initial leaf litter chemistry, but there are fewer that follow the same litter fully through its decay cycle, thus limiting our understanding of its significance at the ecosystem level. It is important to identify if litter chemistry that differs at the beginning of this process will decay and converge in chemical properties or, if a different initial chemistry will result in a different final chemistry. This is significant as it changes the way in which we can predict how biogeochemical processes will function in a given ecosystem. Our study aims to add information about the chemical processes behind litter decomposition by utilizing litter samples forming 43 datasets from Long-Term Ecological Research (LTER) sites across a wide geographic and climatic gradient with differing land use histories. Archived analyses of litter included data about the decomposer communities by investigating enzymes, phospholipid fatty acids or bacterial biomass, %C and %N, %P, and other elements such as Na. Fe, S, Mg, etc. Litter samples that had previously not been chemically analyzed or that were lacking some analyses at different stages of decay, for instance at 50% mass remaining of the original litter, were assessed to investigate the decomposition process over time. The results from this study will improve our understanding of the factors that contribute to decomposition pathways and how changes in land-use, chemical additions or removal or changing climate trends affect this integral ecosystem process.