The decomposition of organic matter is an essential process that releases nutrients usable by plants and microorganisms. During this process, crucial for life on Earth, carbon dioxide (CO₂) is emitted into the atmosphere. The activity of decomposing microorganisms plays a key role, as their presence and efficiency depend on environmental conditions. Factors such as temperature, oxygen availability, and the quality of plant material can also accelerate or slow down decomposition, influencing nutrient cycling and soil fertility. Thus, the decomposition rate varies according to climate and soil factors such as moisture, acidity, and nutrient content.
Photograph 1. Field techniques involving the placement of tea bags in the Special Protection Area (SPA) Hoces del Río Riaza, in the province of Segovia. Credits: Noé Cuesta.
To assess decomposition, bags containing plant material are weighed before and after being buried in the soil. A scientifically validated method based on tea bags has been developed and is widely employed internationally. This method enables the calculation of the (Teabag Index), making it easier to compare decomposition rates across different regions and improving predictive models for climate change.
Photograph 2. Tea bags (Rooibos and green tea) used for tea bag sampling. Credits: Noé Cuesta.
Within the framework of the LIFE Connect Ricotí project, the experiment has been conducted continuously since 2022. This season, tea bags were placed during the month of March at different locations in Segovia, Cuenca, and Guadalajara. These locations coincide with study areas of Dupont’s lark (Chersophilus duponti); thus, all bags were placed in moorland and steppe laboratory to measure their final weight and decomposition rate habitats. The bags will be collected in June and subsequently dried in the laboratory to measure their final weight and decomposition rate.
Photograph 3. Tea bags are buried approximately 8 cm deep into the soil. Credits: Noé Cuesta.
