Terrestrial LiDAR: a three-dimensional revolution in how we look at trees.

Contents Summary I. Introduction II. Terrestrial laser scanning III. Turning points into trees IV. Current and future applications of TLS V. Conclusions Acknowledgements References SUMMARY: Terrestrial laser scanning (TLS) is providing new, very detailed three-dimensional (3D) measurements of forest canopy structure. The information that TLS measurements can provide in describing detailed, accurate 3D canopy architecture offers fascinating new insights into the variety of tree form, environmental drivers and constraints, and the relationship between form and function, particularly for tall, hard-to-measure trees. TLS measurements are helping to test fundamental ecological theories and enabling new and better exploitation of other measurements and models that depend on 3D structural information. This Tansley insight introduces the background and capabilities of TLS in forest ecology, discusses some of the barriers to progress, and identifies some of the directions for new work.