Parent Material Effect on Soil Organic Carbon Concentration under Primeval European Beech Forests at a Regional Scale

The research presented herein explores soil organic carbon concentration (SOCC) under monodominant primeval forests of European beech trees and their association with parent material on a regional scale. Soil sampling to a maximum depth of 0.8 m was conducted in six localities in the West, East, and South Carpathians, Eastern Albanides, and Central Apennines, situated on different parent materials. Samples were analysed for SOCC by the dry combustion method. The average SOCC values representing individual localities ranged from 12.5 g kg−1 to 154.8 g kg−1 with a 99.7% coefficient of variation. SOCC association with climatic variables and forest stand volume data available from the literature were assessed by a Pearson correlation coefficient. Differences in SOCC among localities caused by site conditions were treated as a fixed factor in Welch’s ANOVA and found to be significant (p < 0.05) in the majority of cases. The associations between SOCC and climatic variables or stand volume were nonsignificant or perturbed. Since they validly explained less than 10% of the overall SOCC variance, the results of multiple comparison tests were assessed and interpreted in view of distinct parent materials.