KSCSTE-Kerala Forest Research Institute, Peechi, Trichur, Kerala, 680 653, India.
Cochin University of Science and Technology, Kochi, 682 022, India.
Environ Monit Assess. 2024 Aug 19;196(9):821. doi: 10.1007/s10661-024-12988-2.
Spatial distribution and edaphic influences on soil organic carbon (SOC) are key determinants of carbon sequestration potential, and analysis of aggregate-protected SOC gives an in-depth understanding of the stability of carbon stored in soils. The present study evaluated the edaphic effects on the SOC in four different forest types-tropical evergreen forest, tropical moist deciduous forest, tropical dry deciduous forest and shola forest-in the southern high hills agro-ecological zone of Western Ghats, India. SOC stocks at depths of up to 1 m varied significantly across forest types, with the highest levels observed in the shola forest type (441.08 Mg C/ha) and the lowest in the dry deciduous forest (138.17 Mg C/ha). Around 70% of SOC was found in upper layers (0-30 cm) in all the studied forest types. Evaluation by a fixed-effect model showed that forest type, soil depth and aggregate size significantly affected SOC storage in these systems. An assessment of the relative importance and effect of 14 edaphic factors on SOC content in different forest types using the random forest model showed that the algorithm could explain 93.68%, 41.72%, 45.53% and 75.2% variability of SOC concentration across shola, dry deciduous, moist deciduous and evergreen systems, respectively. Across all forest types, except for dry deciduous forests, soil texture was found to be the primary factor influencing SOC, surpassing all other edaphic parameters. Ionic interactions by way of metal oxides like Ca, Al, Fe, Mg and H influenced the SOC in tropical forest systems. The insights into SOC dynamics and the edaphic factors regulating them offer valuable guidance for forest management in tropical regions, particularly regarding climate change mitigation.
土壤有机碳（SOC）的空间分布和土壤特性是决定碳固存潜力的关键因素，而对团聚体保护 SOC 的分析可以深入了解土壤中储存的碳的稳定性。本研究评估了土壤特性对印度西高止山脉南部高丘农业生态区四种不同森林类型（热带常绿林、热带湿润落叶林、热带干旱落叶林和疏林地）SOC 的影响。SOC 储量在 1 米深的范围内在不同的森林类型中差异显著，疏林地的 SOC 储量最高（441.08 Mg C/ha），而干旱落叶林的 SOC 储量最低（138.17 Mg C/ha）。约 70%的 SOC 存在于所有研究森林类型的上层（0-30 cm）。固定效应模型的评估表明，森林类型、土壤深度和团聚体大小对这些系统中的 SOC 储量有显著影响。随机森林模型评估了 14 种土壤特性因子对不同森林类型 SOC 含量的相对重要性和影响，结果表明，该算法可以分别解释疏林地、干旱落叶林、湿润落叶林和常绿林系统中 SOC 浓度的 93.68%、41.72%、45.53%和 75.2%的变异性。除了干旱落叶林外，在所有森林类型中，土壤质地被发现是影响 SOC 的主要因素，超过了所有其他土壤特性参数。通过 Ca、Al、Fe、Mg 和 H 等金属氧化物的离子相互作用影响了热带森林系统中的 SOC。对 SOC 动态及其调节土壤特性的深入了解为热带地区的森林管理提供了有价值的指导，特别是在应对气候变化方面。
