Worldwide Historical Estimates of Leaf Area Index, 1932-2000

摘要: Approximately 1000 published estimates of leaf area index (LAI) from nearly 400 unique field sites, covering the period 1932-2000, have been compiled into a single data set. LA1 is key parameter for global and regional models biosphere/atmosphere exchange carbon dioxide, water vapor, other materials. It also plays an integral role in determining energy balance land surface. This set provides benchmark typical values ranges variety biomes cover types, support model development validation satellite-derived remote sensing vegetation parameters. The are linked to bibliography over 300 original source references. These historic mostly natural seminatural (managed) ecosystems, although some agricultural included. Although methodologies changed decades, it useful represent inconsistencies (e.g., maximum value reported particular biome) that actually found scientific literature. Needleleaf (coniferous) forests by far most commonly measured biome/land types this compilation, with 22% measurements temperate evergreen needleleaf forests, boreal needleleafmore » crops next common (about 9% each). About 40% records were past 10 years (1991-2000), further 20% collected between 1981 1990. Mean LAI ({+-} standard deviation), distributed 15 classes, ranged 1.31 {+-} 0.85 deserts 8.72 4.32 tree plantations, (needleleaf broadleaf) displaying highest among terrestrial classes. We identified statistical outliers set, both globally according different but despite decreases mean reported, our overall conclusions remained same. report documents its contents, availability on Internet Oak Ridge National Laboratory Distributed Active Archive Center Biogeochemical Dynamics. Caution advised using these data, which wide range assumptions may not allow comparisons sites.« less