How does the LAI-2200 method compare with other indirect methods?
A Other gap fraction methods of determining canopy structure include point quadrats (Warren Wilson and Reeve 1959), high-contrast fisheye photography (Anderson 1970, Bonhomme and Chartier 1972), traversing a light sensor beneath a canopy (Norman et al 1979, Lang et al 1985, Perry et al 1988), and using a linear light sensor (Walker et al 1988). The LAI-2000 method is closest to fisheye photography. The LAI-2200 has the advantage over photography of immediate on-site analysis, but the disadvantage of not having a picture (permanent record) on which to do a number of other types of analyses. The point quadrat technique is only suited to small canopies. The remaining techniques involve using the sun as a canopy probe. The obvious disadvantages are two: the sun must be out, and one must wait for the sun to move to get data at various angles. The LAI-2200 gets all the angle data at once, and does not require the sun to be out. (In fact, it is best if the sun is not out). On the other hand,
