부산대학교 도서관

Seagrass ecosystems have been identified as long‐term carbon sinks whose conservation could serve as a tool to mitigate carbon emissions. Seagrasses alter landscapes in a way that stimulates carbon biosequestration, but discussions of their role in atmospheric CO2mitigation disregard the co‐occurring inorganic carbon cycle, whose antagonist effect on CO2sequestration can buffer and potentially outweigh the effects of Corgproduction on net carbon exchange with the atmosphere. This study examines the extent of both organic carbon (Corg) and inorganic carbon (Cinorg) stocks as proxies for long‐term production and calcification in the poorly studied seagrass meadows of southeastern (SE) Brazil and compares values to Florida Bay (U.S.A.), a well‐studied system known for both high autotrophy and calcification, representing extremes of CaCO3soil content. Seagrass soils in SE Brazil contain an average of 67.6 ± 14.7 Mg Corgha−1in the top 1 m, compared to an average of 175.0 ± 20.4 Mg Corgha−1for their counterparts in Florida Bay. Cinorgas CaCO3in SE Brazil averaged 141.5 ± 60.0 Mg Cinorgha−1in the top meter of soil while the warmer, calcification‐promoting waters of Florida Bay had higher soil Cinorgareal stock, averaging 754.6 ± 26.7 Mg Cinorgha−1. When the CO2evasion related to CaCO3production is considered, seagrass ecosystems with high CaCO3content may have CO2sequestered via Corgaccumulation negated by CO2produced by calcification. These findings prompt the reconsideration of carbon inventory methods and encourage regionally‐ and community‐specific assessments of CO2sequestration abilities of seagrass ecosystems.