Terrestrial laser scanning data acquired from 55 sample plots (32 m × 32 m) in Evo, Southern Finland during April 22 to May 14, 2024 (leaf-off conditions) using a Riegl VZ-400i terrestrial laser scanner with following configuration: Acquisition Dates: 22 April – 14 May 2024 Conditions: Leaf-off Scanner Model: Riegl VZ-400i Measurement principle: Time-of-flight Wavelength: 1550 nm Laser Beam Diameter (at exit): 7 mm Beam Divergence: 0.35 mrad (at the 1/e² points) Beam Diameter at 10, 20 and 30 m: 10, 14, 18 mm Pulse Repetition Rate: 600 kHz Maximum Returns per Pulse: Up to 8 Scan Pattern: ‘Panorama 40’ Angular Resolution: 0.04° Point Spacing at 10 m: 3.5 mm Vertical Field of View: 100° (Scan Position, upright), 360° (Scanner tilted 90°) Horizontal Field of View: 360° (Scan Position, upright), 100° (Scanner tilted 90°) The data was processed in the RiSCAN PRO software (version 2.19.3) where the built-in LIS TreeAnalyzer plugin, developed by Laserdata GmbH, was utilized for identifying and segmenting individual trees and measuring their characteristics. For each sample plot (n = 55), a point cloud file (.laz) is provided with the following attributes for each point record: - X coordinate (Easting) [m], ETRS-TM35FIN (epsg: 3067) - Y coordinate (Northing) [m], ETRS-TM35FIN (epsg: 3067) - Z coordinate (Height) [m], N2000 - Reflectance (distance-corrected intensity) [dB] - Return number - Return count - Point Cloud ID (scan position ID) - Height above ground level [m] - Tree ID number In addition, a text file Evo_TLS_2024_treelist_v3.csv is provided, containing following attributes for each tree segmented, in the order of their appearance: - x: X coordinate of stem cross section mid-point (Easting) [m], ETRS-TM35FIN (epsg: 3067) - y: Y coordinate of stem cross section mid-point (Northing) [m], ETRS-TM35FIN (epsg: 3067) - z: Z coordinate of stem cross section height [m], N2000 - plot_id: Sample plot ID number - tree_id: Tree ID number - tree_sp: - Tree species: 0 = not defined; 1 = Scots pine (Pinus sylvestris L.); 2 = Norway spruce (Picea abies (L.) H. Karst.); 3 = Birches (Betula spp. L.); 4 = European aspen (Populus tremula L.); 5 = grey alder (Alnus incana (L.) Moench); 6 = common alder (Alnus glutinosa (L.) Gaertn.); 7 = rowan (Sorbus aucuparia L.); 9 = Larix sp.; 10 = Fir (Abies sp.); 11 = unknown species; 12 = common juniper (Juniperus communis L.). - stem_diam: Stem diameter at the height of tree identification [m] - tree_height: Tree height [m] - crown_area: Crown projection area [m2] - crown_diam: Crown diameter [m] - circle_compl: Circle completeness [%] (related to Hough circle finding) - goodness_of_fit: Goodness of fit [%] (related to Hough circle finding) - pts_on_circle: n.o. points on the fitted circle (related to Hough circle finding) - slice_height: point cloud slicing height (± 0.15 m) in tree identification A text file Evo_TLS_2024_stand_attributes_v3.csv is also included to contain stand-level forest inventory attributes for all the sample plots: - plot_id: Sample plot ID number - x: X coordinate of sample plot center (Easting) [m], ETRS-TM35FIN (epsg: 3067) - y: Y coordinate of sample plot center (Northing) [m], ETRS-TM35FIN (epsg: 3067) - N: number of trees per hectare - G: mean basal area [m2/ha] - V: total stem volume [m3/ha] - Dg: basal area-weighted mean diameter [cm] - Hg: basal area-weighted mean height [m] - Pine_BA%: Scots pine basal area percentage - Spruce_BA%: Norway spruce basal area percentage - Birch_BA%: Deciduous trees basal area percentage

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