DOI: 10.23729/fd-5a800660-8bd8-35ef-ac9f-ac5c45f7fa77
title: Terrestrial Laser Scanning Point Clouds and Tree Attributes from 55 Sample Plots at the Evo Test Site (Spring 2024)

description: 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