All trees greater than 1 inch in diameter within a plot are marked and tagged. Tree are identified to species. Tree diameter is measured at a painted line at breast height, generally at 1.35 m above ground surface. Measurements are taken after July 15 of each year to represent end of year measurement, sometimes measured as late as spring of following year. All trees are assigned a canopy class of dominant (d), codominant (c), intermediate (i), suppressed or overtopped (s), or intermediate between two canopy classes if two letters are listed divided by a slash.
Tree height was determined using a laser range finder and clinometer. The observer stood far enough away from the tree so that both the base and top could be observed simultaneously. Whenever possible the observer stayed at the same altitude as the base of the tree. The distance to the top and angle were measured using the range finder and clinometer respectively and repeated for the base. The height was then calculated using the following equation:
H = (sin(angle 1)* x) + (sin(angle 2) * y)
Where H is the tree height, angle 1 is the angle to the top of the tree, x is the distance to the top of the tree, angle 2 is the angle to the bottom of the tree, and y is the distance to the base of the tree.