1. Leaf Area Index (LAI): a historical field data set for global vegetation modeling and remote sensing validation Jonathan Scurlock and Dick Olson ORNL Distributed Active Archive Center Environmental Sciences Division Oak Ridge National Laboratory Tennessee, USA Humid Savanna - Lamto, Ivory Coast

2. LAI data set for the ORNL DAAC Like net primary productivity (NPP), leaf area index (LAI) is a key parameter for global and regional models of biosphere/atmosphere exchange. Data are being compiled for the ORNL Distributed Active Archive Center (Oak Ridge, Tennessee, USA). Modeling and EOS validation both require field measurements to constrain LAI values for different biomes (typical min, max values, phenology, etc.) Collaborators/ advisers: Tom Gower (Univ. Wisconsin), Greg Asner (Univ. Colorado), Ranga Myneni (Boston University) Demonstration Web page (documentation and data): http://daac.ornl.gov/npq/html_docs/lai_des.html Data are also searchable via Mercury: http://mercury.ornl.gov/ornldaac/

3. LAI data set for the ORNL DAAC Achieved to date over 1000 LAI records compiled from literature, with associated variables such as latitude/longitude, elevation, stand age, above-ground NPP, etc. spreadsheet of raw data available, plus analysis of mean values, standard deviations, etc. by biome/land-cover type, list of original-source references and map of measurement locations LAI values are quite variable, ranging from a minimum of 0.1- 0.18 (desert and tundra) to a max of 47.0 (!) only ~10-15% of the records have LAI >8.0 (reasonable threshold unlikely to be exceeded except with peculiar conditions or methodology)

4. Distribution of LAI measurement sites is reasonably representative in terms of geographical scope

5. 200 150 100 50

7. N.B. increase in number of LAI records and decline in mean measured value by decade