Abstract

An experiment is presented determining the accuracy with which low cost multispectral aerial reflectance data obtained from a hand-held 35-mm camera can be used to estimate green LAI (leaf area index). Conducted on a heathland in Berkshire, England, the experiment used ground and aerial reflectance data from four vegetation associations representing two contrasting types of semi-natural vegetation. The green LAI of the four vegetation canopies was estimated from multispectral aerial photography combined with a detailed knowledge of the relationship between canopy reflectance and green LAI. At an error of + or - 0.1 green LAI for the young and mature Calluna association and + or - 1.0 green LAI for the Pteridium and Pteridium/Calluna associations, accuracies of green LAI estimation were around 74 percent. At times of canopy stability in the winter and early spring and at the same errors of estimate, accuracy increased to 84 percent.