Document Type


Publication Date

Spring 2023


Environmental Sciences | Environmental Studies

Description, Abstract, or Artist's Statement

The carbon released from leaf decomposition plays a critical role in the riparian ecosystem and aquatic food web. By testing rates of leaf decomposition in urban streams we can survey the health of a watershed by sampling the carbon release amidst key locations in the area. In this study, we had two objectives: The assessment of the role of shredder macroinvertebrates in leaf decomposition, and the assessment of leaf decomposition rates across sites in Silver Creek. This project is part of the long term assessment of Davenport streams conducted by Augustana College's Upper Mississippi Center. We hypothesized that by excluding macroinvertebrates from sample leaf bags using 13.97 x 20.06 cm 0.15 mm mesh nylon bags, Sugar Maple leaves would decompose slower than the normal leaf bags of an 20.32 x 20.32 cm 7 mm wider mesh, which would allow macroinvertebrates inside. We put 4.0 (± 0.1g) dry sugar maple ( Acer saccharum)leaves inside all bags. We centralized our mesh size comparison at one key site, deploying three groups of five wide mesh bags and three groups of five fine mesh bags. Four other sites received one group of five wide mesh bags only. The fine mesh bags were anchored to the streambed inside empty wide mesh bags so that all bags had the same footprint on the streambed. Bags were staked down underwater for twenty one days and retrieved. Leaf packs were rinsed of debris and dried to a constant weight in a 60 °C drying oven. Invertebrates were collected from each leaf pack while rinsing. Contrary to our hypothesis, there was no significant difference in mass loss between fine and wide mesh bags, however wide mesh bags were significantly more variable in their mass loss than fine mesh bags. Leaf mass loss differed significantly across sites. Preliminary findings suggest that factors such as differential macroinvertebrate colonization or the variability of headwater sites may have influenced the varied results of our leaf bags.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.