A study on spatiotemporal variability of soil organic carbon content (SOC) over India is carried out based on a remote sensing data-driven terrestrial ecosystem model and the regional databases. The model is initialized with the equilibrated solutions corresponding to undisturbed balanced biosphere condition and then marched forward with realistic forcing for the recent decades. Both the model solution and regional data show a good agreement between them with a large SOC values with mean 12 kg m −2 for the forest and cropland-dominated regions, a moderate value (8 kg m −2 ) for the mixed shrub and grassland, and small for the grassland regions (4 kg m −2 ) correspondingly for 30 m upper active layer of the soil. The model SOC shows a significant seasonal variability across all the vegetation types with peak value during spring season (March–April) and trough during the autumn (September–October). The SOC budget of the country is around 13 Pg for the top active layer of the soil. It has shown a significant increasing trend of 22 Tg year −1 for the study period resulted from the positive growth rate of 25 Tg year −1 for the cropland and negative growth rate of 3 Tg year −1 for the forest region. The extrapolated annual national SOC budget is 25 Pg correspondingly for 1 m depth soil layer.

中文翻译：

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基于生态系统模型和区域数据库的印度土壤有机碳含量时空变化

基于遥感数据驱动的陆地生态系统模型和区域数据库，对印度土壤有机碳含量 (SOC) 的时空变异性进行了研究。该模型用与未受干扰的平衡生物圈条件相对应的平衡解进行初始化，然后在近几十年来的现实强迫下向前推进。模型解和区域数据均显示出它们之间的良好一致性，具有较大的 SOC 值，森林和农田主导区域的平均 12 kg m -2 ，灌木和草地混合的中等值（8 kg m -2 ） ，而对于草地区域（4 kg m -2 ）则较小，相应地对于 30 m 上部活动层土壤。模型 SOC 显示了所有植被类型的显着季节性变化，峰值在春季（3 月至 4 月）和秋季（9 月至 10 月）低谷。该国土壤顶层活性层的 SOC 预算约为 13 Pg。由于耕地25 Tg year -1 的正增长率和林区3 Tg year -1 的负增长率，研究期间显示出22 Tg year -1 的显着增加趋势。对于 1 m 深度的土壤层，外推的年度国家 SOC 预算为 25 Pg。由于耕地25 Tg year -1 的正增长率和林区3 Tg year -1 的负增长率，研究期间显示出22 Tg year -1 的显着增加趋势。对于 1 m 深度的土壤层，外推的年度国家 SOC 预算为 25 Pg。由于耕地25 Tg year -1 的正增长率和林区3 Tg year -1 的负增长率，研究期间显示出22 Tg year -1 的显着增加趋势。对于 1 m 深度的土壤层，外推的年度国家 SOC 预算为 25 Pg。