At each site, we measured breast height diameter and coordinates of each aspen.
Monitors were instructed carefully to avoid common mistakes such as a twisted or lax tape, a thumb placed under the tape, and measuring below breast height.
Basal area per hectare, the sum of the cross sectional area of the trees, typically measured at breast height, is one of the simplest measures of forest stand density and composition.
A description of trees and their geographic coordinates, together with sampling dates, is provided in Additional file 5. Tree height was measured in 2007 (when the collection was established) using a vertex dendrometer and trunk circumference was measured at breast height (1.3 m).
Treatments had variable effects on stem diameter increment of crop trees, measured at breast height during the second and third years after treatments were imposed.
The diameter of the woody vegetation was measured at breast height (dbh).
Stress wave velocity was measured at breast height (1.3 m above the ground) and parallel to the maximum curvature (convex side, see Figure 1).
As an example, ρg measured at breast height (1.3 m) for a randomly selected sample tree in the dataset was 985.08 kg m−3.
The trees were measured at breast height (1.4 m) for diameter over bark, and after felling wood discs were cut from the ends of the 6 m butt log for six trees at Kinleith and thirteen trees at Mangatu Forest, and at breast height for 32 trees at Rotoehu Forest.
The diameter of sampled trees was measured at breast height (DBH) and the trees classified into 6 symptom classes based on the symptoms they expressed: 0 – tree without symptoms, I - <10% brown leaves, II - 10 50% brown leaves, III – 50 80% brown leaves, IV - >80% brown leaves, V- dead tree without leaves.
