As mentioned before a statistical approach based on sample plots gets used to estimate the timber volume of an entire stand. A sample plot has an area of about 20x20m. Within such a plot all trees are registered with height and dbh (diameter at breast hight) and the timber volume per hectare can be calculated what yields to a direct estimation of the timber volume for the entire stand.
Airborne laser scanning is able to provide information on all the trees within a stand. In the case of eucalyptus it is the tree height, for other species like spruce or fir each tree can be modeled and a crown diameter extracted, here the point density is not such a limiting factor. By estimating the dbh based on this information the timber volume of each tree can be calculated and summed up for all trees of a stand