In Colombia, the rise of agricultural and pastureland expansion continues to exert increasing pressure on the structure and ecological processes of savannahs in the Eastern Plains. However, the effect of land use change on soil properties is often unknown due to poor access to remote areas. Effective management and conservation of soils requires the development spatial approaches that measure and predict dynamic soil properties such as soil organic carbon (SOC). This study estimates the SOC stock in the Eastern Plains of Colombia, with validation and uncertainty analyses, using legacy data of 653 soil samples. A random forest model of 9 environmental covariate layers was used to develop predictions of SOC content. Model validation was determined using the Taylor series method, and root-mean-square error (RMSE) and mean error (ME) were calculated to assess model performance. We found that the model explained 50.28% of the variation within digital SOC content map. Raster layers of SOC content, bulk density, and coarse rock fragment within the Eastern Plains were used to calculate SOC stock within the region. With uncertainty, SOC stock in the topsoil of the Eastern Plains was 1.2 G t ha-1. We found that SOC content contributed nearly all the uncertainty in the SOC stock predictions, although better determinations of SOC stock can be obtained with the use of a more geomorphological diverse dataset. The digital soil maps developed in this study provide predictions of extant SOC content and stock in the topsoil of the Eastern Plains, important soil information that may provide insight into the development of research, regulatory, and legislative initiatives to conserve and manage this evolving ecosystem.

中文翻译：

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哥伦比亚东部平原土壤有机碳储量的近似值

在哥伦比亚，农业和牧场扩张的兴起继续对东部平原大草原的结构和生态过程施加越来越大的压力。然而，由于无法进入偏远地区，土地利用变化对土壤特性的影响通常是未知的。土壤的有效管理和保护需要开发空间方法来测量和预测土壤有机碳 (SOC) 等动态土壤特性。本研究使用 653 个土壤样本的遗留数据，通过验证和不确定性分析，估计了哥伦比亚东部平原的 SOC 储量。9 个环境协变量层的随机森林模型用于开发 SOC 含量的预测。使用泰勒级数方法确定模型验证，计算均方根误差 (RMSE) 和平均误差 (ME) 以评估模型性能。我们发现该模型解释了数字 SOC 内容图中 50.28% 的变化。东部平原内 SOC 含量、体积密度和粗岩石碎片的栅格层用于计算该区域内的 SOC 储量。由于存在不确定性，东部平原表土中的 SOC 储量为 1.2 G t ha-1。我们发现 SOC 含量几乎贡献了 SOC 储量预测中的所有不确定性，尽管使用更多样化的地貌数据集可以更好地确定 SOC 储量。本研究中开发的数字土壤图提供了对东部平原表土中现存 SOC 含量和存量的预测，重要的土壤信息可以为研究的发展提供洞察力，