Li-Cor Plant Canopy Analyzer
Leaf Area Index (LAI) is the ratio of foliage area to ground area. The LAI-2200 computes LAI from measurements made above the canopy and below the canopy, which are used to determine canopy light interception at 5 angles. These data are fit to a well-established model of radiative transfer inside vegetative canopies to compute leaf area index, mean tilt angle, and canopy gap fraction.
The benefits of the LAI-2200 over other methods such as ceptometry and hemispherical photography are that it:
Makes few assumptions about canopy structure.
Measures gap fraction at 5 zenith angles with a single measurement. In contrast to linear sensors, there is no need to wait for the sun angle to change or make multiple measurements to acquire this data.
Measures up to a 360° azimuthal view for each zenith angle. This provides a large sample area for good spatial averaging.
Filters light below 490 nm to avoid leaf transmission and reflectance errors that occur in some LAI sensors.
Requires no calibration.
Can measure small plots and isolated plants.
Computes LAI instantly and includes powerful post-processing software.