Comparing the Use of Three Dendrometers for Measuring Diameters at Breast Height

Abstract

Three dendrometers are used to measure dbh. Two of the devices are the well-known and widely used d-tape and caliper. The third device is the lesser-known sector fork. In this study, measurements of dbh were collected from each dendrometer for each tree in nine plots, with each of the three plots nested in one of the diameter classes (small, medium, and large). The results from repeated-measures analysis of variance show that different dendrometers, the interaction between the dendrometer and diameter class, and the interaction between the dendrometer and plot significantly affected the dbh measurements. Statistically significant differences were detected in most of the comparisons of dbh measured by the three dendrometers. However, the actual mean differences and limits of agreement (Bland, J.M., and D.G. Altman. 1986. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1:307–310) were small enough to support the claim that the dbh measurements made by the three dendrometers agree well in measurements of the small and medium trees (in this study, dbh of <16 in.). Thus, these statistically significant differences are not biologically and/or practically important. For the large trees (dbh 16 in. or more), the dbh measured by d-tape and caliper still agreed well. The sector fork should be used cautiously in measuring large trees.

Evaluating the Accuracy of Remote Dendrometers in Tree Diameter Measurements at Breast Height

“…The tree diameter is one of the most important and commonly measured individual tree attributes. It is used to determine tree volume, basal area, and other tree characteristics, which are essential components of a forest inventory, it helps in developing forest management and planning options, and it can be of value in conducting research (Moran and Williams 2002, Melkas et al 2008, Liu et al 2011. In most countries, diameter-at-breast height (DBH) is the most common tree diameter measurement.…”

“…A DBH is described as the outside bark stem diameter of a tree at a point located 1.30 m above the ground base, on the uphill side of a tree, except in the United States (1.37 m), and Japan and Korea (1.2 m) (van Laar and Akça 2007, Kershaw et al 2017). Tree DBH can be measured using a number of different devices, or dendrometers, which can be divided into two groups: those that contact the stem physically and those that avoid direct contact and facilitate a remote measurement (Ashley and Roger 1969, Clark et al 2000a, Melkas et al 2008, Liu et al 2011. Also, devices can be differentiated based on cost, accuracy, precision, ease of use (Clark et al 2000a, Liu et al 2011.…”

“…Tree DBH can be measured using a number of different devices, or dendrometers, which can be divided into two groups: those that contact the stem physically and those that avoid direct contact and facilitate a remote measurement (Ashley and Roger 1969, Clark et al 2000a, Melkas et al 2008, Liu et al 2011. Also, devices can be differentiated based on cost, accuracy, precision, ease of use (Clark et al 2000a, Liu et al 2011. Direct contact measurement, using traditional diameter tapes and calipers, is the most common and preferred method for field measurements due to its accuracy, efficiency, and simplicity (Clark et al 2000a, Luoma et al 2017.…”

“…Direct contact measurement, using traditional diameter tapes and calipers, is the most common and preferred method for field measurements due to its accuracy, efficiency, and simplicity (Clark et al 2000a, Luoma et al 2017. Over the last century, many studies have been conducted to examine and evaluate the accuracy of different direct contact dendrometers such as the Bitterlich sector fork (Liu et al 2011, Weaver et al 2015, electronic tree measuring fork (Binot et al 1995), Biltmore stick (Jackson 1911, Moran andWilliams 2002), and the Samoan stick (Dixon 1973). With the exception of calipers and tapes, the reliability and subjectivity of the other direct contact dendrometers may limit their use in scientific or large-scale inventory work (Clark et al 2000a).…”

Quantifying the uncertainty caused by sampling, modeling, and field measurements in the estimation of AGB with information of the national forest inventory in Durango, Mexico

“…Thus, it was possible to estimate smaller measurement errors than the ones estimated in other studies, like the study of Kitahara et al (2010), in which measurement errors are estimated comparing the measurements of field crew with measurements made by forest experts. Or similar approaches like in our first empirical study, in which the errors are estimated from measurements made by different field crew members (Elzinga et al, 2005;Liu, Bitterlich, Cieszewski, & Zasada, 2011;Luoma et al, 2017;McRoberts et al, 1994;Melson et al, 2001).…”