Leaf Area Index (LAI) data from the scientific literature, covering the period from 1932-2000, have been compiled at the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC) to support model development and validation for products from the MODerate Resolution Imaging Spectroradiometer (MODIS) instrument. There is one data file which consists of a spreadsheet table, together with a bibliography of more than 300 original-source references. Although the majority of measurements are from natural or semi-natural ecosystems, some LAI values have been included from crops (limited to a sub-set representing different crops at different stages of development under a range of treatments). Like Net Primary Productivity (NPP), Leaf Area Index (LAI) is a key parameter for global and regional models of biosphere/atmosphere exchange. Modeling and validation of coarse scale satellite measurements both require field measurements to constrain LAI values for different biomes (typical minimum, maximum values, phenology, etc.). Maximum values for point measurements are unlikely to be approached or exceeded by area-weighted LAI, which is what satellites and true spatial models are estimating.
This data set is one of the products of the International Satellite Land-Surface Climatology Project, Initiative II (ISLSCP II) data collection which contains 50 global time series data sets for the ten-year period 1986 to 1995. A complete description of the data, their derivation, acknowledgements, and references provided by the ISLSCP II Data Management Staff is included with this data set as a companion file named 1_ornl_lai_point_doc.pdf.
ISLSCP II is a consistent collection of data sets that were compiled from existing data sources and algorithms, and were designed to satisfy the needs of modelers and investigators of the global carbon, water and energy cycle. The data were acquired from a number of U.S. and international agencies, universities, and institutions. The data and documentation have undergone two peer reviews.
ISLSCP is one of several projects of Global Energy and Water Cycle Experiment (GEWEX) [http://www.gewex.org/] and has the lead role in addressing land-atmosphere interactions -- process modeling, data retrieval algorithms, field experiment design and execution, and the development of global data sets.
Related Data Sets
Cite this data set as follows:
Scurlock, J.M.O., G.P. Asner, and S.T. Gower. 2010. ISLSCP II Leaf Area Index (LAI) from Field Measurements, 1932-2000. In Hall, Forrest G., G. Collatz, B. Meeson, S. Los, E. Brown de Colstoun, and D. Landis (eds.). ISLSCP Initiative II Collection. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/971
The archived data sets for ISLSCP II have been organized by categories. This data set is in the vegetation category--a collection of vegetation and albedo data sets.
Data Set Spatial Extent: 1,008 point measurements world-wide
Western most Longitude: -156.67 W
Easternmost Longitude: 172.75 E
Northernmost Latitude: 71.30 N
Southernmost Latitude: -54.50 S
Data Set Temporal Extent: January 1932 through December 2000
Data Set Temporal Resolution: annual peak LAI
Data File Format:
There is only one data file for this data set. The data file ornl_point_lai.dat has a total of 1,009 rows and 19 columns all separated by a single tab character. Both numerical and text fields are included as described in accompanying documentation. A value of -999 denotes a missing numerical value (-99.99 for Latitude and Longitude fields). "N/A" means that a particular text field was not available.
Further research and file descriptions are provided in the following companion files:
0_ornl_lai_readme.txt: Companion file to LAI data set with listing of column headings and biomes considered.
ornl_lai_refs.txt: Bibliography of over 300 references used in the LAI compilation.
LAI_TM.pdf: ORNL Technical Memorandum, ORNL/TM-2001/268 (Scurlock et al. 2001).
Scurlock, J. M. O., G. P. Asner, S. T. Gower. 2001. Worldwide Historical Estimates and Bibliography of Leaf Area Index, 1932-2000. ORNL Technical Memorandum ORNL/TM-2001/268. Oak Ridge National Laboratory, Oak Ridge, Tennessee.
These data are available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC) [http://daac.ornl.gov].
Telephone: +1 (865) 241-3952