Woodlot for Windows [enfor consultants ltd]




WOODLOT for Windows 2.1 - Reference Manual
4.3 How WOODLOT Calculates a Harvest Rate?

A harvest rate is selected (this value could be any number but WOODLOT uses the Hanzlik rate) as a starting point. WOODLOT then simulates the harvest by looping through the following steps. If the harvest fails the rate is decreased and if it completes the rate in increased. The amount equals half the previous decrease or increase. Except if the first rate passes it will increase by the initial rate until it fails.

  1. Setup variables
      • The cut rate is set to the harvest rate
      • The year is set to 0

  2. WOODLOT chooses a polygon to harvest in order of importance:
    1. If any partial cut polygons ready to harvest
      • Select the polygon that has been ready to harvest the longest.
    2. Else if any polygons in the queue are ready to harvest
      • Select the polygon that has been ready to harvest the longest.
    3. Else the next polygon in the sort order
      • If this polygon is not ready to cut add to queue
      • Test next polygon
    4. Else STOP
      • Report error message
      • Lower harvest rate
      • Start procedure over again

  3. WOODLOT then Harvests the current polygon:
    1. While the polygon has more volume to cut than the cut rate,
      • The current harvest rate will be removed
      • The year will be incremented (to grow the trees)
      • The age and height constraints will be checked
      • The cut rate is set to the harvest rate.
    2. Then
      • The remaining volume will be removed
      • The cut rate is set to the harvest rate minus the amount harvested.
by Enfor Consultants Ltd. Last Updated March 1999