LAIv

Leaf Area Index (LAI) is used to quantify the amount of foliage in a landscape. MEGAN uses a value, referred to as LAIv),  that is representative of the m2 of one sided leaf area per m2 of canopy area (vegetation covered area). 

If the time period and region you need is not available below then you can generate your own LAIv data using satellite databases of LAI and vegetation cover fraction (VCF) from sources such as  as NASA or  ESA.  Note that these LAI data  must first be converted to LAIv (LAI divided by the vegetation cover fraction) before used in MEGAN2.1 (MEGAN3.2 will accept either LAI or LAIv).

For example, if the LAI for a specific location is 2 m2/m2 and the vegetation cover fraction (VCF) is 0.4 then the LAIv = LAI/VCF = 2/0.4 = 5. Note that the unit used for input to MEGAN2.1 and MEGAN3.2 pre-processor is m2 leaf area per 10 m2 surface area so if you generate LAIv in m2/m2 then multiply this by 10 to get m2 leaf area per 10 m2.  

The following datasets have been used previously to drive MEGAN.  

Note the values range from 0 to 6000 and the units are m2 leaf area per 1000 m2 ground area. These values should be divided by 100 to use with MEGAN2.1 or MEGAN3

      Note the values range from 0 to 100 and the units are m2 leaf area per 10 m2 ground area.

       Note the values range from 0 to 100 and the units are m2 leaf area per 10 m2 ground area.

       Note the values range from 0 to 100 and the units are m2 leaf area per 10 m2 ground area.