The organic carbon stock (SOC) (t/ha) was calculated in different approaches in order to enhance the differences among methods and their utility regarding specific studies. Using data obtained in Romania (2000-2012) from 4,500 profiles and 9,523 soil horizons, the organic carbon stock was calculated for the main forest soils (18 types) using three different methods: 1) on pedogenetical horizons, by soil bulk density and depth class/horizon thickness; 2) by soil type and standard depths; 3) using regression equations between the quantity of organic C and harvesting depths. Even though the same data were used, the differences between the values of C stock obtained from the three methods were relatively high. The first method led to an overvaluation of the C stock. The differences between methods 1 and 2 were high (and reached 33% for andosol), while the differences between methods 2 and 3 were smaller (a maximum of 23% for rendzic leptosol). The differences between methods 2 and 3 were significantly lower especially for andosol, arenosol and vertisol. A thorough analysis of all three methods concluded that the best method to evaluate the organic C stock was to distribute the obtained values on the following standard depths: 0 - 10 cm; 10 - 20 cm; 20 - 40 cm; > 40 cm. For each soil type, a correlation between the quantity of organic C and the sample harvesting depth was also established. These correlations were significant for all types of soil; however, lower correlation coefficients were registered for rendzic leptosol, haplic podzol and fluvisol.

This study of the variation process of the chemical properties of eutric Cambisols on altitudinal levels, forest station subclasses and geomorphologic units, was based on soil analyses from 847 soil horizons gathered from 379 profiles. These profiles were distributed on Romania's entire forest area. The average values of the eutric Cambisol's chemical properties fit were within the known limits for this type of soil, but there were slight variations based on altitude, forest station subclass and geomorphologic units. As expected, the most chemical properties decrease according to the altitudinal levels, from altitudes of over 900 metres to altitudes of under 300 metres. At the level of the Ao horizon, the pH has a value of 5.78 (the soils are slightly acid) at altitudes lower than 300 m and of 5.03 (the soils are mildly acid) at altitudes higher than 900 m.The saturation degree basis is 72% (the soils are mezobasic towards eubasic) at altitudes lower than 300 m, and 56.7% (the soils are mezobasic towards oligomezobasic) at altitudes higher than 900 m. The exchangeable hydrogen decreases from 16.95 me/100 g soil at altitudes higher than 900 m to 9.01 me/100 g soil at altitudes lower than 300 m.