Track

A 'track' is a Patchworks term for all of the information that describes the development of a stand type over time. A track includes information about inventory characteristics and how they change over time, information about treatment types, operability limits, harvest products and stand responses.

Each polygon in the block table may be associated with one or two tracks at any one time (depending if it has managed and/or unmanaged area, see Figure 20, “Unmanaged and managed portions within blocks”). If a track has managed area it will have a MANAGEDTRACK, and if it has unmanaged area it will have an UNMANAGEDTRACK.

Tracks provide the link between a block and all of its feature attributes, its candidate treatments and resulting products. A track is identified by a unique track label, which is used in a relational database fashion to link all of the features and treatments that have the same track label. For more information about tracks and how they are organized see the section called “Initial Conditions and Forest Dynamics”.

It is possible for more than one block to share the same track definition. In fact all polygons that have the exact same classification values should share the same track. Stands with the same classification values but of a different age will share the same track, but will have different offset values (see the section called “Offset vs. Age”). Stands may change tracks when a treatment is applied, if the treatment changes one of the classification values. It is possible that a stand may stay on the same track after a treatment has been applied, so long as the treatment did not change the classification of the stand (e.g. the silvicultural treatment caused the stand conditions to remain the same).

Stands do not change tracks when succession occurs. Succession is handled endemically within the definition of a track so that feature curves and future treatment options are interpolated correctly within a stand life cycle that does not have breakup and renewal rules (see the section called “Patchworks data model example”). Because of this, tracks tend to describe the growth and development of stand conditions over very long time horizons, at least as long as the planning horizon of the simulation.