NACP LiDAR-based Biomass Estimates, Boreal Forest Biome, North America, 2005-2006

This data set provides estimates of aboveground biomass (AGB) for defined land cover types within World Wildlife Fund (WWF) ecoregions across the boreal biome of Alaska and western and eastern Canada, roughly between 45 and 70 degrees N. The study focused on within-growing-season data, i.e. leaf-on conditions. The AGB estimates were derived from a series of models that first related ground-based measured biomass to Portable Airborne Laser System (PALS) LiDAR measurements, and a second set of models that related the airborne estimates of biomass to Geoscience Laser Altimeter System (GLAS) LiDAR canopy structure measurements. The GLAS LiDAR biomass estimates were extrapolated by land cover types and ecoregions across the entire biome area. The study compiled remotely sensed forest structure data collected in June of 2005 and 2006 from the GLAS LiDAR instrument aboard the NASA Ice, Cloud, and land Elevation (ICESat) satellite and from the PALS airborne instrument flown at various times from 2005-2009 over both the ground plots and the ICESat GLAS flight path. For a consistent biome-level analysis, ecoregions contained within the boreal forest biome were identified by the World Wildlife Fund's (WWF) ecoregion map of the world (Olson et al., 2001). Land cover maps were used to identify land cover types for stratification purposes within eco-regions. Land cover data for Canada were provided by the Earth Observations for Sustainable Development (EOSD) project centered on year 2000, with images from 1999 to 2002. The National Land Cover Data (NLCD) 2001 classification was used for Alaska based on data collected between 1999 and 2004. The ground-based measurements are not provided with this data set.本数据集提供了阿拉斯加及加拿大西部和东部北方生物群系内（大致位于北纬45°至70°之间）世界自然基金会（WWF）生态区内特定土地覆盖类型的地上生物量（AGB）估算值。该研究聚焦于生长季内的数据，即叶盛期条件下的数据。 AGB估算值来源于一系列模型：第一组模型将地面实测生物量与便携式机载激光系统（PALS）激光雷达（LiDAR）测量值相关联；第二组模型将机载生物量估算值与地球科学激光测高系统（GLAS）激光雷达冠层结构测量值相关联。GLAS激光雷达生物量估算值通过土地覆盖类型和生态区外推至整个生物群系区域。 该研究汇编了2005年和2006年6月从美国国家航空航天局（NASA）冰、云与陆地高程卫星（ICESat）搭载的GLAS激光雷达仪器获取的遥感森林结构数据，以及2005-2009年间不同时间从地面样地和ICESat GLAS飞行路径上空飞行的PALS机载仪器获取的数据。为实现一致的生物群系尺度分析，北方森林生物群系内的生态区通过世界自然基金会（WWF）的全球生态区地图（Olson等，2001）确定。土地覆盖图用于在生态区内识别土地覆盖类型，以进行分层。本数据集未提供地面实测数据。