Soil characteristics and vegetation structure in a heavily deteriorated mangrove forest in the Caribbean Coast of Colombia

Mass mortality and biomass of mangrove trees are related to soil factors in the Caribbean Coast of Colombia. Soil properties measured were particle size distribution, bulk density, organic matter, total nitrogen, total phosphorus, pH, redox potential, salinity and extractable nitrogen (NO2, NO3, NH4) and phosphorus (PO4). Sampling was performed at three locations along two 50 m transects at each site. Soil nutrient concentrations of either exchangeable nitrogen or phosphorus were comparable to other reported values. Redox potentials (E-h) were variable probably due to microtopographic conditions and to the amount of water and organic matter present in the soil. Hydrogen potentials (pH) are within the range reported as normal for mangrove soils. Locations with highest biomass had an average soil salinity of 35 with a range of 20 to 53. Sites with dead or dwarfed vegetation had an average soil salinity of 74 and minimum and maximum values observed were 52 and 100 respectively Statistical analysis exhibited temporal and spatial differences in soil salinity and suggest that this parameter is most correlated to the development and distribution of mangrove vegetation in the area indicating that basal area and biomass volume are inversely correlated with soil salinity.