NACP FOREST AGE MAPS AT 1-KM RESOLUTION FOR CANADA (2004) AND THE U.S.A.(2006)

This data set provides forest age map products at 1-km resolution for Canada and the United States (U.S.A.). These continental forest age maps were compiled from forest inventory data, historical fire data, optical satellite data, and the images from NASA?s Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project. These input data products have various sources and creation dates as described in the source paper by Pan et al. (2011). Canadian maps were produced with data available through 2004 and U.S.A. maps with data available through 2006. A supplementary map of the standard deviations for age estimates was developed for quantifying uncertainty.

Note that the Pan et al. (2011) paper is included as a companion file with this data set and was the source of descriptions in the guide.

Forest age, implicitly reflecting the past disturbance legacy, is a simple and direct surrogate for the time since disturbance and may be used in various forest carbon analyses that concern the impact of disturbances. By combining geographic information about forest age with estimated carbon dynamics by forest type, it is possible to conduct a simple but powerful analysis of the net CO2 uptake by forests, and the potential for increasing (or decreasing) this rate as a result of direct human intervention in the disturbance/age status.

本数据集面向加拿大与美利坚合众国（简称美国），提供1公里分辨率的森林年龄地图产品。该跨大陆森林年龄地图整合了森林清查数据、历史火灾数据、光学卫星数据，以及美国国家航空航天局（National Aeronautics and Space Administration, NASA）的陆地卫星生态系统干扰自适应处理系统（Landsat Ecosystem Disturbance Adaptive Processing System, LEDAPS）项目产出的影像。如Pan等人2011年发表的源文献所述，本数据集的各类输入数据来源多元、生成时间各异。其中加拿大森林年龄地图基于截至2004年的公开数据制作，美国森林年龄地图则基于截至2006年的公开数据制作。此外，为量化年龄估算的不确定性，本数据集还配套开发了森林年龄估算标准差专题地图。

需注意，本数据集已将Pan等人2011年的研究论文作为配套文件附带，本指南中的描述均源自该文献。

森林年龄隐含反映了过去的森林干扰遗留特征，是干扰发生后时长的简洁直接替代指标，可应用于各类关注干扰影响的森林碳循环分析。将森林年龄的空间分布信息与不同森林类型的碳动态估算结果相结合，即可开展简洁却极具应用价值的森林净二氧化碳（CO₂）吸收量分析，同时可评估人类通过直接干预森林干扰/年龄状态，对该吸收速率产生增减变化的潜力。