Abstract

Airborne laser scanning (ALS) based height and intensity information was exploited for the vertical stratification of vegetation layers in a multilayered Mediterranean ecosystem. A new methodology for the separation of different strata was implemented using supervised
classification of a two-dimensional feature space spanned by ALS return height (terrain corrected) and discrete return intensity. The approach was validated using extensive field measurements from treated plots, ranging from a single vegetation strata to a more complex multi-layered ecosystem. It was possible to derive maximum, minimum and mean layer height with satisfying accuracies, the bias between field and ALS based layer properties being in order of some decimetres, while standard deviation were generally less than a meter. Fractional cover of the layers could be estimated with errors of about 10 to 15%, even for lower layers potentially concealed by higher vegetation. Concluding, ALS based height and intensity information based on discrete return data was found to be well suited to
derive vertical stratification of vegetation layers, however full-waveform data should be able to provide additional information on the physical properties of these layers.