Communication Assessing Precision in Conventional Field Measurements of Individual Tree Attributes Ville Luoma 1,4,*, Ninni Saarinen 1,4, Michael A. Wulder 2, Joanne C. White 2, Mikko Vastaranta 1,4, Markus Holopainen 1,4 and Juha Hyyppä 3,4 1 Department of Forest Sciences, University of Helsinki, P.O.Box 27 (Latokartanonkaari 7), 00014 Helsinki, Finland; ninni.saarinen@helsinki.fi (N.S.); mikko.vastaranta@helsinki.fi (M.V.); markus.holopainen@helsinki.fi (M.H.) 2 Canadian Forest Service (Pacific Forestry Centre), Natural Resources Canada, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada;
[email protected] (M.A.W.);
[email protected] (J.C.W.) 3 Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute FGI, National Land Survey, Geodeetinrinne 2, 04310 Masala, Finland; juha.hyyppa@nls.fi 4 Centre of Excellence in Laser Scanning Research, Finnish Geospatial Research Institute FGI, National Land Survey, 04310 Masala, Finland * Correspondence: ville.luoma@helsinki.fi; Tel.: +358-44-047-6070 Academic Editor: Timothy A. Martin Received: 16 December 2016; Accepted: 4 February 2017; Published: 8 February 2017 Abstract: Forest resource information has a hierarchical structure: individual tree attributes are summed at the plot level and then in turn, plot-level estimates are used to derive stand or large-area estimates of forest resources. Due to this hierarchy, it is imperative that individual tree attributes are measured with accuracy and precision. With the widespread use of different measurement tools, it is also important to understand the expected degree of precision associated with these measurements. The most prevalent tree attributes measured in the field are tree species, stem diameter-at-breast-height (dbh), and tree height.