Abstract:

This paper mainly reviewed the methods for estimating forest leaf area index (LAI) in different space scales, their advantage and disadvantage as well as their development trends are also discussed in this paper. The forest LAI in a small scale can be achieved by measuring it in situ for which there are five groundbased methods including destructive harvesting method, leaf litter collection, allometric equation, optical measurements and inclined point quadrat. On a regional or global scale, the forest LAI can be estimated by remote sensing. These methods involved in the statistical modeling technique, canopy reflectance models which base on modeling the relationships between canopy characteristics and reflectance, artificial neural network model, and lookup table.

Key words: leaf area index, scale, ground measurements, remote sensing inversion, groundvalidate