Effects of parent material on soil microbial biomass carbon and basal respiration within young afforested areas

Afforestation is economically and ecologically important for protecting land and improving soil quality. This study evaluates how soil basal respiration, physicochemical and microbiological characteristics are affected by parent material variety in afforesting degraded areas. For this, some soil physical and chemical parameters, microbial respiration (MR), soil microbial biomass carbon and microbial indexes (Cmic/Corg and MR/Cmic) were determined. The results showed that the physical, chemical and microbiological properties of the soil formed from limestone were better than those of the basaltic-andesite soil. An independent samples t-test demonstrated that the afforested area on the limestone parent material had significantly higher microbial biomass C than the basaltic-andesite parent material. The microbial quotient (Cmic/Corg) of the limestone soil was positively affected by afforestation. In addition, the highest basal respiration value (1.01 ± 0.33 CO2–C 10−2 µg g−1 h−1) was observed for the limestone at the topsoil. The lowest metabolic quotient values were determined for the basaltic-andesite parent material on both topsoil and subsoil (1.99 and 1.42 μg CO2-C mg Cmic−1 h−1, respectively). This study revealed the importance of determining the parent material and its soil characteristics for successfully managing forest applications in degraded areas. Limestone soil sequesters more carbon and promotes microbial activities with a higher Cmic/Corg than the basaltic-andesite soil. Furthermore, the microbial quotient remained low during the 10 years in which the forest was in its sapling stage.