The canopy surface and stand development: assessing forest canopy structure and complexity with near-surface altimetry

A first-return laser rangefinder deployed from a low-flying helicopter provided inexpensive, repeatable, and high-resolution measurements of the shape of the outer forest canopy in stands of four successional stages on the Maryland coastal plain. The traces of canopy height in these stands revealed structural characteristics such as cover, maximum and mean heights which were consistent with corresponding ground measurements. Differences in the statistics on canopy structure corresponded to general developmental trends in these stands, including the development of maximum height and surface rugosity. Furthermore, some of the outer canopy statistics related to measures of internal organization, such as the shape of the foliage height profile and the leaf area index. These observations suggest that such measurements could be used readily to classify stand structure and developmental stage, and to deduce some aspects of internal organization of vegetation.