Tree expansion factor
n. The number of trees per unit area represented by a record in a tree list.
The tree expansion factor for sampled trees depends on the inventory design used. For fixed-area plot sampling, the tree expansion factor is the inverse of the plot size. For example, if a tree is measured on a 1/10th acre plot, the tree expansion factor would be 10 trees per acre. When point sampling is conducted using a prism, the tree expansion factor can be determined from the basal area factor of the prism and the diameter at breast height (DBH) of the tree (Avery and Burkhardt 1994).