Role of the altitude on the organic matter preservation in soils under a secondary praire on the Majella massif, Italy.

Summary. In order to investigate the influence of elevation and consequently of the climate, we studied the trend of organic matter storage in prairie soils along a elevation gradient (from 950 m to 2500 m above sea level) in a mountainous environment located in the Majella massif (Central Italy). The results showed that the humic C and the total organic C (TOC) increased until about 1550 m above sea level and decreased afterwards, while the humic C/ TOC ratio increased until about 1500 m, decreased from about 1500 and 1900 m and increased again at the highest elevations. Along the elevation gradient, the total N showed a constant increase. 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.