Four soil series selected for investigation represented the most diverse natural morphological and decompositional ranges of Histosols occurring within the Florida Everglades. The least decomposed Histosol was represented by the Montverde series, with Pahokee representing an intermediate stage of decomposition, and Okeelanta representing the most advanced stage. Although the surface of Torry represented an advanced stage of decomposition, it was also examined because of exceptionally high clay content and significantly lower rate of subsidence. Stages of decomposition decreased with increasing depth within series due to decreasing oxidative conditions. Therefore the least decomposed horizon was represented by the 36-to 81-cm horizon of Montverde followed by the 109 to 137-cm horizon of Torry, and the most decomposed horizons were the surface horizons of Okeelanta and Torry.
Bulk density and percent ash decreased with increasing profile depth, and generally increased with Montverde < Pahokee < Okeelanta < Torry. Generally the water-retaining characteristics increased with increasing profile depth and decreased with Montverde > Pahokee > Okeelanta > Torry. The humin fraction generally constituted the highest organic fraction percentage and increased with profile depth. Comparison of surface horizons show Montverde to have the largest humin fraction percentage, Pahokee and Okeelanta to be intermediate, and Torry to be lowest. Fulvic acid fraction percentage was lowest for the deeper horizons of both Montverde and Torry, and highest for the surface horizons of Pahokee and Okeelanta. The first two horizons of Torry contained the highest clay and humic acid percentage and the largest humic acid/fulvic acid ratios. Total elemental analysis revealed striking similarities for all horizons and organic fractions. Similarities for all horizons also occurred with functional group analysis except for the two clayey horizons of Torry which had a higher carboxyl group content and a lower phenolic hydroxyl group content in the humin and humic acid fractions. Generally, total acidic and carboxyl group content was greatest in the fulvic acid fraction and lowest in the humin fraction. Conversely, the humin fraction contained the largest alcoholic hydroxyl group content.