A Pivotal Change in Forest Inventory is Occurring

By James D. Arney, Forest Biometrics Research Institute (FBRI)

• Consider a Large Working Forest Ownership (0.5 – 1.5 million acres)

• Traditional Inventory Approach (1970 – 1995) – “Phototype & Cruise”

  • Human Photo Interpreter using an Experienced Eye
    • Stratify the Forest (48 – 72 Strata Maximum)
      • 4 – 6 Primary Species Groups
      • 4 Size Classes (Seedling, Sapling, Pole, Timber)
      • 3 Density Classes (Poor, Medium, Dense)
    • Cruise 20% of All Forest Acres / Stratum (Limited by Annual Budget)
      • 20% of 1 million acres at $7.00 / acre = $1,400,000 Initial Cruise
    • Extrapolate 80% of All Acres based on Average Tree Lists by Stratum
    • May Re-Merchandize and Grow Individual Stands

• Remote Forest Mapping (1996 – 2019) – “Raster Theme Generator”

  • Satellite 30m Raster-based Forest Themes for Species and Volume
    • Combinations of Satellite Spectral Bands and Coarse LiDAR
      • 4 – 6 Primary Species Groups
      • 3 – 7 Volume / Biomass Classes
    • Ground-based Calibration Plots for Species / Volume Signatures
  • Every Acre based on Direct Aerial Interpretation, No Extrapolations
  • Entire Forest easily Re-Classified & Updated Periodically
  • Cruise 1.5% Annually (target Defect & Harvest Planning)
  • No Capacity to Re-Merchandize or Grow Themes

• Remote Forest Mapping (2020 +) – “Raster Polygon Generator”

  • Satellite 10m Raster-based Forest Themes for Species, Size & Density
    • Combinations of Satellite Spectral Bands and Medium LiDAR
      • 4 – 8 Primary Species Groups
      • 4 – 8 Height Classes (20-foot strata)
      • 4 – 6 Density Classes (Crown Competition Factor index)
    • Ground-based Calibration Plots for Species / Height / Density
  • Every Acre based on Direct Aerial Classification, No Extrapolations
  • Entire Forest easily Re-Classified & Updated Periodically
  • Cruise 1.5% Annually (target Defect & Harvest Planning)
  • May Re-Merchandize and Grow Individual Stands