Tree Measurement Index - Archive of Older Posts

People want trees to follow certain attractive mathematical distributions,
but the trees don't have to...  Dr. Lee Frelich, Feb 09, 2008,

Diagrams by Jeff LaCoy, 2009

Tree Measuring Guidelines of the Eastern Native Tree Society



On March 14, 2010 The Eastern Native Tree Society and Western Native Tree Society switched from discussion lists on Google Groups to a new discussion list in a Bulletin Board format at:  Posts made since the inception of the BBS on march 14, 2010 will be sorted and archived on the BBS. Click on the link above to go to the equivalent section on the new BBS. This website will continue to serve as a front end for the ENTS and WNTS groups. It will continue to serve as a repository of older posts, and will serve as the host site for special projects and features that are not well suited for a BBS format. Please visit the BBs for the latest information and trip reports.


Measurement Notes:


Mismeasured Trees

Measured Trees

Measurement Basic Math Concepts

Bank of Solved Problems/ Problem Workbook



Canopy/Crown Spread

Rucker Index

Tree Dimension Index

Diversity Index

Height Records per Site




Height Density Analysis

Height/Diameter Ratio

Tree Shape

  • Live Oak Shapes ENTS, Larry, This diagram of Live Oak shapes demonstrate that the species is relatively short when compared to their width and girth. The proportions plot well below those of a standard tree shape. An average tree shape plots in the center of the diagram. The diagrams to not relate to the overall size of the tree, just to the relative proportion of the height - girth - and spread. If compared to the diagram of the initial data set generated from Jess Riddle's ENTS Maximum List, the cluster representing the Live oak falls on the extreme edge of the general pattern of tree shapes as a group. The height proportion exhibits a maximum of 17.23% of the shape value and a minimum of 6.55%, the girth (minimum of 19 feet in the data set) exhibits a maximum of 58.25% and a minimum of 40.25%, and Average Crown Spread maximum of 49.08% and a minimum of 30.92%. This forms an extremely tight cluster of shapes for these trees. In general these represent the largest specimens of Live oak and represent open grown specimens, but the tightness of the shape cluster is still remarkable.... more   Jan 25, 2010
  • Numerical Plot of Live Oaks For those of you wondering about the validity of the entire Ternary Plot idea of tree shapes, look at this data set generated by Larry Tucei's Live Oak listings. Yes, there is some bias in the plot because it only includes data for trees mostly 20 feet in girth, but overall it shows a really tight pattern.... more   Jan 25, 2010.
  • A Numerical Method of Plotting Tree Shapes A Numerical Method of Plotting Tree Shapes Anyone who looks at trees realizes that different trees have different shapes. Tree shapes also appear to vary by tree type. Three basic parameters are generally used to approximate tree shape: height, girth, and average crown spread. These values are used in a big tree formula developed by American Forests [link] to calculate the point value of individual trees for inclusion in their Big Tree List. The Eastern Native Tree Society (ENTS) [link] uses height and girth in calculating in their own ENTS Points formula and use either two or all three of these parameters in calculating the Tree Dimension Index (TDI) first proposed by Will Blozan for comparing trees within a single species [link].... more   Jan 23, 2010.
  • Tree Form Analysis Jan 2005
  • Form Class Nov 2006

Age/Tree Rings

University of Arkansas Tree Ring Laboratory The Tree-Ring Laboratory (TRL) was established in 1979 and concentrates on the development of exactly-dated annual tree-ring chronologies from ancient forests worldwide. These tree-ring chronologies are based on small non-destructive core samples taken from living trees, and cross-sections cut from dead logs. Tree-ring chronologies provide unique archives of environmental history, and have important applications to climatology, ecology, hydrology, seismology, archaeology, and history.



Tree Top Offset / Lean

Live Crown Ratio


Mapping and GPS Location

Multistemmed Trees

Forest Structure:

Tree Formulas

  • American Forests Big Tree Formula:  Before nominating a tree, you need to know 3 measurements: (1) Trunk Circumference (measured in inches), (2) Vertical Tree Height (measured to the nearest foot), and (3) Average Crown Spread (measured to the nearest foot). American Forests uses the following calculation to determine a tree's total points:  Trunk Circumference (inches) + Height (feet) + Average Crown Spread (feet) = Total Points. 

Size Distribution Analysis




Ideas To Be Pursued

Colby Rucker:



Earthworm Sampling

How to Measure a Big Tree Slide Show  (2002)

  • How to measure a big tree (2002)
    • Slide 1:  Measuring height using a laser rangefinder and clinometer
    • Slide 2:  Measuring height using the principle of similar triangles
    • Slide 3:  Measuring the circumference of a tree
    • Slide 4:  Measuring the crown spread of a tree
    • Slide 5:  To calculate the Champion Tree Points using the American Forests Formula


Copyright 2002, 2003 Eastern Native Tree Society