Soil organic carbon stocks (SOCs) and enzyme activities are key indicators for assessing ecosystem dynamics in mountainous regions. This study examined variations in SOCs and the activity of major enzymes along an altitudinal gradient (0–2400 m) and a depth gradient (0–100 cm) in mountain forests. Two approaches, fixed depth (FD) and equivalent soil mass (ESM), were applied to estimate SOCs. The results showed that SOCs were significantly influenced by altitude, depth, and their interaction (P ≤ 0.001). SOCs increased with altitude but decreased with depth; the highest and lowest values up to one meter depth were recorded at altitudes of 1800–2400 m and 0–600 m, respectively, representing a 1.14-fold increase in SOCs at higher elevations. Moreover, mean SOCs in deep layers (80–100 cm) showed about a 70% reduction compared with the surface layer (0–20 cm). The ESM method provided greater accuracy than the fixed-depth method (CV = 2.61% vs. 3.65%). The activities of β-glucosidase, urease, and arylsulfatase increased with altitude but decreased with depth, whereas cellulase, acid phosphatase, and alkaline phosphatase decreased with both factors. In contrast, dehydrogenase (DHA) activity increased with depth and exhibited a negative correlation with SOCs (r = –0.92). Additionally, SOCs were strongly correlated with microbial biomass carbon (r = 0.99) and enzyme activities (r ≥ 0.82), while its depth distribution remained consistent across the entire altitudinal gradient. These findings underscore the importance of jointly considering soil depth and altitude in SOC modeling and the sustainable management of mountain ecosystems.
Jozedaemi, E. , Golchin, A. and Misaghi, M. (2025). Biogeochemical Responses of Soil Organic Carbon and Enzymatic Activity to Elevation and Depth: Comparing Fixed Depth and Equivalent Soil Mass Approaches. Iranian Journal of Soil and Water Research, (), -. doi: 10.22059/ijswr.2025.399910.669990
MLA
Jozedaemi, E. , , Golchin, A. , and Misaghi, M. . "Biogeochemical Responses of Soil Organic Carbon and Enzymatic Activity to Elevation and Depth: Comparing Fixed Depth and Equivalent Soil Mass Approaches", Iranian Journal of Soil and Water Research, , , 2025, -. doi: 10.22059/ijswr.2025.399910.669990
HARVARD
Jozedaemi, E., Golchin, A., Misaghi, M. (2025). 'Biogeochemical Responses of Soil Organic Carbon and Enzymatic Activity to Elevation and Depth: Comparing Fixed Depth and Equivalent Soil Mass Approaches', Iranian Journal of Soil and Water Research, (), pp. -. doi: 10.22059/ijswr.2025.399910.669990
CHICAGO
E. Jozedaemi , A. Golchin and M. Misaghi, "Biogeochemical Responses of Soil Organic Carbon and Enzymatic Activity to Elevation and Depth: Comparing Fixed Depth and Equivalent Soil Mass Approaches," Iranian Journal of Soil and Water Research, (2025): -, doi: 10.22059/ijswr.2025.399910.669990
VANCOUVER
Jozedaemi, E., Golchin, A., Misaghi, M. Biogeochemical Responses of Soil Organic Carbon and Enzymatic Activity to Elevation and Depth: Comparing Fixed Depth and Equivalent Soil Mass Approaches. Iranian Journal of Soil and Water Research, 2025; (): -. doi: 10.22059/ijswr.2025.399910.669990
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