Knowing what the stand contains
Forest inventory quantifies species composition, age structure, density, and merchantable volume. Inventory data drives harvest scheduling, regeneration planning, and carbon accounting.
Sampling design
- Fixed-radius plots — count and measure trees within defined radius (e.g., 1/10 acre).
- Variable-radius (prism) sampling — basal area factor selects trees proportional to diameter.
- Strip or line surveys — traverse lines recording all trees on each side.
Metrics recorded
Species, diameter at breast height (DBH, 1.37 m), height, crown class, defect, and regeneration density. DBH and height feed volume equations for timber estimation.
Growth and mortality
Re-measure permanent plots over decades to calculate annual increment and mortality rates. Growth models project future stand conditions under alternative management scenarios.