European blueberry (Vaccinium myrtillus L.) shrubs are key components of forest understory, playing an essential role in soil formation processes and contributing to habitat stability [1,2]. Given its ecological significance, understanding the carbon cycling of V. myrtillus is crucial. Stable carbon isotopes are widely used in plant ecology to assess plant-environment interactions and provide valuable insights into plant carbon dynamics and the role of plants in the carbon biogeochemical cycle [3]. However, research employing stable carbon isotopes to study blueberry ecophysiology remains scarce.
This study examines organ-specific stable carbon isotope composition (\(\delta^{13}C\)) and carbon content (C %) dynamics in V. myrtillus. Plant samples were collected in August of 2021 along the eastern shore of Lake Gėla in Nemenčinė Forest, Vilnius District. A total of 25 specimens were collected and transported to the laboratory, where they were dried, separated by organs (roots, dry stems, green stems, and leaves), and ground into a fine powder. \(\delta^{13}C\) values and carbon content were measured using elemental analysis–isotope ratio mass spectrometry (EA-IRMS).
The results showed that blueberry carbon content was the lowest in leaves and the highest in stems. The lowest \(\delta^{13}C\) values were found in roots, while the highest were in stems. These results indicated that stems of V. myrtillus serve as the carbon sinks at the whole-plant level. However, no statistically significant correlation was observed between carbon content and \(\delta^{13}C\) values, indicating no direct relationship between these parameters. Our study enhances the understanding of carbon dynamics in blueberry shrubs, providing new insights into the ecophysiology of V. myrtillus and its functioning in forest ecosystems.