Fig. 1

a Comparison of two silhouettes from the same sessile oak tree. Left, TLS point cloud; right, digitized architecture obtained with the single image photogrammetric (SIP) method (software used: QGIS (QGIS Development Team 2016)); different line weights represent different orders of branches; basic measurements are shown: CRL (left crown radius), CRR (right crown radius), DBH (diameter at breast height), H (tree height) and CWA (crown width asymmetry). The scale is constant for both silhouettes, the object size (height) measured with TLS is 20.75 m and 20.83 m measured with the image-based method. b Transformed image and measurement of number of trees neighbouring the target individual within an 8-m radius