<p>The large amounts of combustible materials stored in forests can serve as potential biomass fuels for energy conversion. The pyrolysis dynamics in dry and wet forest biomass, as well as the biomass types affecting the energy conversion efficiency remain unclear. In this study, the pyrolysis characteristics of three biomass wastes (pine needles, decayed leaves, and peat mosses) from different forest layers (litter, duff, and organic soil) in both dry and wet conditions were experimentally investigated using thermo-gravimetric analysis, and were modeled by a parallel reaction scheme encompassing water evaporation, hemicellulose, cellulose, and lignin degradation. Higher moisture caused a narrower decomposition temperature zone of organic matter, influencing the yields of volatiles during pyrolysis. The final temperature of pyrolysis stage of main organic matter in wet samples occurred prior to that in dry samples (approximately 5–49 K). The kinetic model showed that lignin decomposition presented the lowest values (10.05 kJ mol⁻¹) in terms of the discrepancy in activation energies among the samples. Moreover, the activation energy (48.93 ± 2.78 kJ mol⁻¹) of water evaporation was found to be similar not only among biomasses, but also between the dry and wet conditions. This study contributes to an enhanced understanding of the pyrolysis capacity and energy utilization potential of dry and wet biomasses from different forest layers.</p>