Hydrological connectivity in preserved and degraded microtidal mangroves in Mexico

This study characterized the mangrove flooding regime in both preserved and degraded conditions. One-year time series of flooding within the mangroves were analyzed using the Fast Fourier and Wavelet transform to determine the correlation between the hydrological connectivity and mangrove flood regime modulators (tide, wind, and rainfall). The semi-diurnal tide (0.053 m²/Hz) was the primary modulator of the mangrove flooding regime in Cozumel Island; in Terminos Lagoon, the diurnal tide had a higher amplitude (0.081 m²/Hz) compared to Cozumel, both tides characteristic of the Caribbean Sea and the Gulf of Mexico. In Terminos, the sea breeze (diurnal) was an essential modulator (coherence 1) of changes in mangrove flooding when the influence of the tide decreased. However, wind was not a significant modulator of mangrove flooding in Cozumel. In both sites, rainfall did not modulate the flood regime except for a few events when approximately 10 mm of rainfall accumulated in 3-h periods. Tide, wind, and rainfall influenced the flood regimes of degraded sites less than preserved sites. We observed prolonged periods of exposed soil or standing water in degraded sites due to the lack of hydrological connectivity. Continuous monitoring of mangrove flooding is crucial for detecting of changes and preventing degradation. Identifying these changes accurately is essential for implementing effective hydrological restoration strategies. In Cozumel Island and Terminos Lagoon, the dead mangrove areas have significant potential for vegetation recovery due to the absence of physical barriers to their development.