Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
Proc Natl Acad Sci U S A. 2011 Jun 14;108(24):9899-904. doi: 10.1073/pnas.1019576108. Epub 2011 May 31.
Developing countries are required to produce robust estimates of forest carbon stocks for successful implementation of climate change mitigation policies related to reducing emissions from deforestation and degradation (REDD). Here we present a "benchmark" map of biomass carbon stocks over 2.5 billion ha of forests on three continents, encompassing all tropical forests, for the early 2000s, which will be invaluable for REDD assessments at both project and national scales. We mapped the total carbon stock in live biomass (above- and belowground), using a combination of data from 4,079 in situ inventory plots and satellite light detection and ranging (Lidar) samples of forest structure to estimate carbon storage, plus optical and microwave imagery (1-km resolution) to extrapolate over the landscape. The total biomass carbon stock of forests in the study region is estimated to be 247 Gt C, with 193 Gt C stored aboveground and 54 Gt C stored belowground in roots. Forests in Latin America, sub-Saharan Africa, and Southeast Asia accounted for 49%, 25%, and 26% of the total stock, respectively. By analyzing the errors propagated through the estimation process, uncertainty at the pixel level (100 ha) ranged from ± 6% to ± 53%, but was constrained at the typical project (10,000 ha) and national (>1,000,000 ha) scales at ca. ± 5% and ca. ± 1%, respectively. The benchmark map illustrates regional patterns and provides methodologically comparable estimates of carbon stocks for 75 developing countries where previous assessments were either poor or incomplete.
发展中国家需要对森林碳储量进行强有力的估算，以便成功实施与减少毁林和森林退化所致排放量（REDD）相关的气候变化缓解政策。在这里，我们呈现了一幅涵盖三大洲、面积达 25 亿公顷的森林生物量碳储量的“基准”图，涵盖了所有热带森林，这将对项目和国家层面的 REDD 评估非常有价值。我们利用来自 4079 个实地清查样地和森林结构卫星光探测和测距（Lidar）样本的数据组合，绘制了活生物量（地上和地下）的总碳储量图，以估算碳储量，再加上光学和微波图像（1 公里分辨率）进行景观外推。研究区域森林的总生物量碳储量估计为 2470 亿吨碳，其中 1930 亿吨碳储存在地上，540 亿吨碳储存在地下根系中。拉丁美洲、撒哈拉以南非洲和东南亚的森林分别占总储量的 49%、25%和 26%。通过分析估计过程中传播的误差，像素级（100 公顷）的不确定性范围为±6%至±53%，但在典型的项目（10000 公顷）和国家（>100 万公顷）尺度上分别限制在约±5%和±1%。基准图说明了区域模式，并为 75 个发展中国家提供了具有可比性的碳储量估算方法，这些国家以前的评估要么很差，要么不完整。
