Forest Estate Model. Forest Planning Studio (FPS) version 6.0.2.0 was used to complete the timber supply analysis. This model has been used previously in the timber supply analysis of several other TSA and TFL management units. FPS was developed by Dr. Xxxx Xxxxxx at the University of British Columbia (UBC) and is a spatially explicit forest estate simulation model. All events in the model are directly linked to stand level polygons or harvest units and thus allow tracking of individual stand attributes and spatial relationships through time. Each polygon belongs to a specific stand group (analysis unit) and has attributes such as age, harvest system, and land base status (THLB or Non-THLB). Results are typically aggregated for reporting at higher levels, such as the harvest flow for the entire unit. A wide range of constraints can be modeled on the land base: harvest exclusion, spatial adjacency or maximum cut-block size, maximum disturbance/young seral, minimum mature/old seral, and equivalent clear-cut area (ECA) limits. Constraints are applied to groups of polygons (cliques) and harvest is restricted if a constraint is not satisfied. A single polygon can belong to many overlapping cliques and each of them must be satisfied in order to allow harvest of the polygon. Where a mature or old cover constraint is not met, harvesting may still occur if there are any eligible stands remaining after the oldest stands are reserved to meet the constraint. Harvest is implemented using a set of priorities to queue stands for harvest. In each period, the model harvests the highest priority eligible stands until it reaches the harvest target or exhausts the list of opportunities. Harvest periods can be set at single years, multiple year periods or a combination of these. Where periods are used, (as in the 10-year periods in this analysis) the midpoint of the period is used as the point where harvest opportunity is evaluated because it is a good balance between the start of the period (pessimistic) and the end of the period (optimistic). Modelling was completed for a minimum of 300 years for each scenario to confirm that the harvest and growing stock levels remain stable, but only the first 250 years are reported. The results presented here do not define a new AAC – they are intended only to provide insight into the likely future timber supply for the community forest. The final harvest level decision will be made by a statutory decision maker.
