Combined Effect of Burrowing Crabs and Tides on Mangrove Carbon Storage

Moritz Klaassen

In this research the combined effect of burrowing crabs and tides on mangrove carbon storage was investigated in a microcosm approach. No significant impact of burrowing crabs on the DOC content in the sediment was found. Remarkably, significantly lower CO2 flux values were found in crab burrows which might be a result of collapsed burrows that trapped leaves in deeper sediment layers. This finding is contrary to most literature and therefore, stresses the importance to incorporate temporal fluctuations in crab burrow stability when studying the effect of crabs on carbon dynamics in mangroves. Significantly higher DOC concentrations were found in microtidal compared to mesotidal treatments. This can be explained by higher leaching rates of mangrove leaves that were submerged longer in microtidal treatments. Further, crabs showed different behavior in tidal treatments as they consumed more leaves in microtidal conditions. The difference in crab behavior is likely to be due to being submerged longer in microtidal treatments and thus, demonstrates the behavioral variability of burrowing crabs under different tidal conditions. Therefore, this study emphasizes the importance of spatial variabilities of carbon dynamics in mangroves.