New Advances in Forest Measurement

Traditionally forestry companies, councils and engineers have used LiDAR to produce digital terrain maps (very high quality contour maps) for use in a range of harvest planning, engineering and roading applications. LiDAR is an optical remote sensing technology that involves sending high intensity laser pulses which are then reflected off objects such as trees, buildings and the ground and recorded for later processing into three dimensional images.

Scion scientists have recently tested this technology to determine if wood properties are influenced by tree crown asymmetry. A pre harvest inventory was carried out across a number of stands and a sample of trees were measured for outerwood velocity at breast height. LiDAR data was then collected over the inventory area and crown metrics were derived from the LiDAR data to estimate tree size and velocity(stiffness).

The study showed that stem velocity can be assessed from crown area and some other LiDAR metrics with a reasonable degree of precision. Additionally, diameter at breast height can be estimated. These relationships are being tested on other sites to further validate the findings. This technology may enable forest owners to more cost–effectively stratify stands for planning purposes on the basis of stiffness over much larger areas then previously possible.