In 1992, all trees 5.0 cm in diameter and larger in the 1.87 ha Harvard Forest DIRT study area were tagged and inventoried according to Harvard Forest protocol. Information recorded for each tree included species, DBH, canopy position, and health. A second survey was conducted in 2000-2001.

Data:

YEAR = Year surveyed
SPECIES = Species name
Bam2/m2 = Basal area of live trees by species, m² tree basal area per m² ground area (m² / m²)
#TREES = Number of live trees by species