Wet tropical forests of Chocó, along the Pacific Coast of Colombia, are known for their high plant diversity and endemic species. With increasing pressure of degradation and deforestation, these forests have been prioritized for conservation and carbon offset through Reducing Emissions from Deforestation and forest Degradation (REDD+) mechanisms. We provide the first regional assessment of forest structure and aboveground biomass using measurements from a combination of ground tree inventories and airborne Light Detection and Ranging (Lidar). More than 80,000 ha of lidar samples were collected based on a stratified random sampling to provide a regionally unbiased quantification of forest structure of Chocó across gradients of vegetation structure, disturbance and elevation. We developed a model to convert measurements of vertical structure of forests into aboveground biomass (AGB) for terra firme, wetlands, and mangrove forests. We used the Random Forest machine learning model and a formal uncertainty analysis to map forest height and AGB at 1-ha spatial resolution for the entire pacific coastal region using spaceborne data, extending from the coast to higher elevation of Andean forests. Upland Chocó forests have a mean canopy height of 21.8 m and AGB of 233.0 Mg/ha, while wetland forests are characterized by a lower height and AGB (13.5 m and 117.5 Mg/a). Mangroves have a lower mean height than upland forests (16.5 m), but have a similar AGB as upland forests (229.9 Mg/ha) due to their high wood density. Within the terra firme forest class, intact forests have the highest AGB (244.3 ± 34.8 Mg/ha) followed by degraded and secondary forests with 212.57 ± 62.40 Mg/ha of biomass. Forest degradation varies in biomass loss from small-scale selective logging and firewood harvesting to large-scale tree removals for gold mining, settlements, and illegal logging. Our findings suggest that the forest degradation has already caused the loss of more than 115 million tons of dry biomass, or 58 million tons of carbon. Our assessment of carbon stocks and forest degradation can be used as a reference for reporting on the state of the Chocó forests to REDD+ projects and to encourage restoration efforts through conservation and climate mitigation policies.

中文翻译：

---

哥伦比亚乔科地区的森林退化和生物量流失。

哥伦比亚太平洋沿岸的Chocó湿热带森林以其高植物多样性和特有物种而闻名。随着退化和森林砍伐压力的增加，通过减少森林砍伐和森林退化（REDD +）机制的排放，这些森林已被优先用于保护和碳补偿。我们结合地面树木清单和机载光探测与测距（Lidar）的测量结果，提供了森林结构和地上生物量的首次区域评估。基于分层随机抽样，收集了超过80,000公顷的激光雷达样本，以提供跨植被结构，扰动和高程梯度的乔科森林结构的区域无偏量化。我们开发了一个模型，可将垂直森林结构的测量结果转换为地表，湿地和红树林的地上生物量（AGB）。我们使用随机森林机器学习模型和形式不确定性分析，使用星载数据，从海岸到高海拔安第斯森林，以1公顷的空间分辨率绘制整个太平洋沿海地区的森林高度和AGB。丘乔山高地森林的平均冠层高度为21.8 m，平均AGB为233.0 Mg / ha，而湿地森林的特征是较低的高度和AGB（分别为13.5 m和117.5 Mg / a）。红树林的平均高度低于旱地森林（16.5 m），但由于木材密度高，其平均AGB值与旱地森林（229.9 Mg / ha）相似。在硬实的森林等级中，完整的森林具有最高的AGB（244.3±34）。8 Mg / ha），其次是退化森林和次生林，其生物量为212.57±62.40 Mg / ha。森林退化造成的生物量损失有所不同，从小规模的选择性伐木和薪柴采伐到大规模采伐树木以进行金矿开采，定居和非法采伐。我们的发现表明，森林退化已经造成了超过1.15亿吨的干燥生物量或5800万吨的碳损失。我们对碳储量和森林退化的评估可以作为向REDD +项目汇报乔科森林状态的参考，并可以通过保护和减缓气候变化的政策鼓励恢复工作。森林退化造成的生物量损失有所不同，从小规模的选择性伐木和薪柴采伐到大规模采伐树木以进行金矿开采，定居和非法采伐。我们的发现表明，森林退化已经造成了超过1.15亿吨的干燥生物量或5800万吨的碳损失。我们对碳储量和森林退化的评估可以作为向REDD +项目汇报乔科森林状态的参考，并可以通过保护和减缓气候变化的政策鼓励恢复工作。森林退化造成的生物量损失有所不同，从小规模的选择性伐木和薪柴采伐到大规模采伐树木以进行金矿开采，定居和非法采伐。我们的发现表明，森林退化已经造成了超过1.15亿吨的干燥生物量或5800万吨的碳损失。我们对碳储量和森林退化的评估可以作为向REDD +项目汇报乔科森林状态的参考，并可以通过保护和减缓气候变化的政策鼓励恢复工作。