Woody biovolume extraction from laser scanned trees

Biomass extraction from indiviual trees measured by terrestrial laser scanning is a valuable tool for forestry and for orchard plantations to extract the economic and ecological parameters of trees. The focus of this paper is to extract the woody biovolume from laser scanned trees based on the SkelTreSkeleton, which is a skeletal structure description. State of the art research proposed skeletons to extract parameters like branch length and branch diameters from trees on the basis of the SkelTre-Skeleton (Bucksch et al. 2010), from trerrestrial LiDAR measurements. In this paper we report on the fully automatic and purely laser-scan derived biovolume extraction of two collected evaluation scenarios: 1.) six leafless orchard apple trees 2.) two European beech trees in a forest Validation measurements on 6 apple trees comprise the lengths and diameters of all branch segments of their canopies, but not their specific weight so that biovolumes can be compared. The beech tree biovolumes are derived from an allometric relation of tree height, breast height diameter and the known density of the beech wood (Rademacher et al. 2009) We apply this method in order to assess the biovolume fractions of branch diameter classes in the tree crowns of 3m high apple trees as well as those of 20m high beech trees in the leafless stage in winter. The results show that for the six apple trees the difference in biovolume between automatic and field measurement is 1.18 litres on average. For the beech trees huge differences were derived demanding better field data to draw actual conclusions from it.