Seasonal dynamics of the carbon dioxide system in crater lake La Alberca de los Espinos: implications for microbialite reefs

Abstract

Temporal variability in metabolic and biogeochemical processes are key factors regulating the growth of microbial reefs or microbialite reefs. This study investigated the dynamics of the carbon dioxide (CO₂) system in the crater lake La Alberca de Los Espinos, the only crater lake in Michoacán that hosts a microbialite. During spring and summer, the system favored carbon capture from the atmosphere through photosynthesis, which increased pH and calcium carbonate saturation (Ω) while decreasing partial pressure of CO₂ (pCO₂). In autumn and winter, the respiration of organic matter was intensified, while photosynthesis was reduced. This caused a reduction in pH and Ω, along with an increase in pCO₂. Consequently, the potential for calcium carbonate decreased and a net flow of CO₂ to the atmosphere was promoted. Together, these results suggest that the crater lake and its microbialite constitute a dynamic system, whose role in the carbon cycle varies seasonally between CO₂ sequestration and release.