Vegetation succession in mires is rather well identified using the paleoecological approach. Recently, the ecological succession concept has been extended to ecosystem functions, e.g., carbon dioxide (CO₂) dynamics. Although a strong link between mire vegetation and carbon dynamics is well acknowledged, the successional changes in mire ecosystem functions have remained practically unstudied, especially under the same climatic control. To study the patterns and dynamics of CO₂ exchange during mire succession, we measured CO₂ exchange and vegetation dynamics over 2 growing seasons along a mire chronosequence on the land uplift coast of the Bay of Bothnia in western Finland. The study showed a decrease in photosynthesis during mire succession that was linked to compositional change in vegetation, i.e., replacement of sedge and herb dominance with the dominance of dwarf shrubs and Sphagna. Similarly, the study revealed decreased variation in gross photosynthesis (P_G) and ecosystem respiration (R_E) over a growing season, which resulted in lower levels of seasonal CO₂ dynamics at older stages. The observed successional trend in phenology and CO₂ dynamics was largely a consequence of the gradual decrease in the abundance of plant groups with efficient photosynthesis and green area production.

Nomenclature: Hämet-Ahti et al., 1998.