Role of the altitude on the organic matter preservation in soils under a secondary prairie on the Majella massif (Italy)

The amount and turnover of the soil organic matter (SOM) is affected by several factors (climate, topography, vegetation, and management), but climate is the main factor that controls the SOM cycle, as it affects composition and physiology of the vegetation and SOM mineralization rate. Since elevation is a factor that influences the climate, the aim of this work was to study the trend of the organic matter storage in prairie soils along an elevational gradient (from 950 to 2550 m above sea level) in a mountainous environment located on the Majella massif (central Italy). The results showed that the humic C and the total organic C (TOC) increased until 1about 1550 m above sea level and decreased afterwards, where, however, the humic C/TOC ratio and the total N increased. This trend suggested that, at the higher altitudes, the low actual temperature controls the mineralization rate, although the low TOC/N ratio suggested a high potential degradability of the organic matter.