Calculation of growth

Introduction

Growth from one period to another period is done as follows (assuming 5-year periods)

1. Make a growth prognosis based on the residual state (state after treatment, if any) of the treatment unit
2. Calculate the state in the new period
3. Assign height and volume to trees in the new period (based on the state before treatment in the new period)
4. Make growth adjustments that should occur before treatment, if required

Make growth prognosis

Growth prognosis is done in the following steps, per prediction unit:

1. Update tree values
   1. Determine Bal for each tree (basal area of all larger trees)
   2. Determine if each tree is an overstorey tree or not
   3. If any tree changed to/from overstorey, update aggregated values for the prediction unit (e.g. mean age, total volume, and mean diameter), since some of these values are per forest layer
2. Assign diameter growth and mortality to trees
3. Assign height growth and mortality to saplings
4. Prognos ingrowth (only if stand is established)
5. Adjust diameter growth due to stand growth model and thinning effect

Calculate state in a new period

1. Set the values for the new period:
   1. Update diameter (for trees) or height (for saplings), and stems (for both trees and saplings)