Studying leaf litter decomposition in the field using commercial tea bags

    

Sarah Staffiere

Advances in Biology Laboratory Education, 2025, Volume 45

https://doi.org/10.37590/able.v45.abs35

Abstract

Decomposition is an important ecosystem process that has a major role in the return of nutrients to the soil and carbon dioxide to the atmosphere. In forest ecosystems, decomposition of organic matter takes place in the leaf litter and upper layer of soil. To allow students to explore how certain anthropogenic alterations to the global climate and landscape affect decomposition rates, a project was conducted in an Ecology course during the fall semester in central Maine comparing the decomposition rates of two kinds of tea leaves under varying applied conditions. Students buried two types of commercial tea bags as a standardized approach (teatime4science.org), and measured the decomposition of green tea leaves (Camellia sinensis) and rooibos tea leaves (Aspalathus linearis) on the forest floor in forested or edge habitats across six weeks of time. Students worked in groups of three or four, and each group applied a different treatment. Treatments included additional weekly watering, continuous warming of the soil, application of fertilizer, differing levels of habitat disturbance, or sites with different dominant tree species. Tea bags were collected weekly for five weeks and final weights of bags were measured after 48 hours in a drying oven. Data for each type of tea were compiled across six lab sections among common treatments. Data analysis in RStudio involved estimating decomposition parameters using non-linear least squares analysis and then comparing those parameters using a two-way AnoVA with control data for both tea types provided by the instructor from field plots kept under ambient conditions. Students communicated the findings of their projects in the form of individual presentations at the completion of the semester. Intended for sophomore-junior college level, biology majors.

Keywords:  decomposition, leaf litter, tea bag, field ecology

University of Maryland (2024)