Thermodynamics of soil organic matter decomposition in semi-natural oak (Quercus) woodland in southwest Ireland

The evolution of soil terrestrial ecosystems is a subject with difficulties to define their maturity and evolutionary state. In the last century, thermodynamics was one of the options considered by ecologists for that goal. Difficulties in quantifying the thermodynamic parameters needed by the evolutionary theories caused that this subject has been practically locked since the end of the last century. Application of thermodynamics needs reactions and one of the main reactions in soil ecosystems are those involved in the decomposition of the soil organic matter. This paper aims to provide an initial step to study those reactions from a thermodynamic perspective. With that goal in mind, thermal analysis and isothermal calorespirometric measurements were made on soil samples collected at three depths in semi-natural oak woodlands at three different sites in southwest Ireland. It is assumed that the organic matter evolves from a less to a higher mature state as soil depth increases. The mat...