Hydroperiod and Salinity Interactions Control Mangrove Root Dynamics in a Karstic Oceanic Island in the Caribbean Sea (San Andres, Colombia)

Mangroves sustain high soil accretion and carbon sequestration rates, yet it is still unknown if they can keep pace with increasing sea level rise (SLR) across a wider range of coastal geomorphic settings. Because rates are controlled by mineral sediment inputs organic matter accumulation, paramount to assess the relative contribution root productivity formation. Here, we evaluated biomass, production, turnover in three mangrove ecotypes evaluate role nutrient limitation, stressors, hydroperiod controlling dynamics San Andres Island (SAI), karstic oceanic island Caribbean Sea. Root production was modulated stress conditions not availability as has been reported for other environments. The lowest biomass allocation, both fine roots were measured under low flooding duration, salinity (<20 PSU) sulfide concentrations (0.84 ± 0.4 mM). Yet, when increased during duration (6207 h y –1 ) oxygen (Eh), tissues reached highest values, including fast (<2 mm; 0.75 ). Our results follow predictions plant longevity cost-benefit hypothesis where plants maintain only until efficiency resource acquisition maximized water acquisition. importance groundwater porewater islands such SAI, use development should be regulated short term avoid loss area concomitant ecosystem services.