A block is the primary spatial unit in the Patchworks model.

A block in Patchworks:


The Patchworks model does not track the spatial distribution of managed and unmanaged areas within a block, but rather assumes that within-block homogeneity is an acceptable portrayal of forest for the purposes of the analysis.

The block.csv file is a starting point of the Patchworks data model. It provides pertinent information about each block and links to more detailed data in other core files. The blocks.csv file contains 5 mandatory fields. See Table 6, “Block file format description” for a detailed description of the block file format.

Table 6. Block file format description

Field nameData typeDescription
BLOCKString A unique, arbitrary alphanumeric label that is used to identify the block for tracking purposes. The label should not contain special characters or spaces.
TYPEString This field contains the string value managed or the string value unmanaged to indicate that the track, offset and area fields apply to the managed or unmanaged component of the stand respectively.
TRACKString An alphanumeric label describing the initial track assignment for this block component. There must be a matching entry for this label in the feature file (see the section called “Features”). Optionally, you may include matching entries in the treatment file (see the section called “Treatments”).
OFFSETinteger An integer representing the starting point along the feature curves at the beginning of the simulation. The offset value is typically the age of the stand. For all aged-stands that are in a steady state and being treated with a selection system the offset value may represent the time since the last harvest entry.
AREAfloatA floating point decimal number representing the area of the block component. The units are problem dependent, but in most cases will be hectares or acres.

This file provides a connection between the spatial and attribute data. The main function of the block file is to associate each block with an identifying label, indicate whether or not the block contains managed, unmanaged or both types of area, the initial track assignments, and the age (offset) and area of the different management types.

Records in the block.csv file are linked to the spatial data by the join key that is in the BLOCK column. There should be a single spatial polygon feature for each unique BLOCK code.


If a block contains both managed and unmanaged area, there will be a separate record for each in block.csv for each type. Both records will start with the same block identification label, but each contains a pointer to the track that describes specific information regarding the unique forest characteristics of either managed or unmanaged types. By using this type of data structure, Patchworks is able to keep track of both managed and unmanaged areas within a single block.


It is an error to have duplicated records in the block.csv with the same BLOCK and TYPE values.


It is an error to have records in the block.csv that do not match to polygon features in the spatial file. It is allowed to have additional polygon features in the spatial file although the application may issue warning messages if this occurs.

More detailed characteristics of the forest are held within the other core files. A track provides a link to the stand conditions in the block. A track is a Patchworks structure that associates blocks with forest dynamics. Every block is associated with tracks that describe changing forest conditions and available management treatments. The block file identifies the track that each portion of the block initially belongs to. This track information can then be used to link the block to a set of curves describing the initial forest conditions in detail.

Example 11. Sample block file records

  1,      unmanaged,  Track.2,   81,      13.78
  2,      managed,    Track.3,   101,     9.31
  2,      unmanaged,  Track.4,   81,      16.13
  3,      managed,    Track.5,   81,      7.51
  3,      unmanaged,  Track.6,   81,      18.12
  6,      unmanaged,  Track.7,   61,      0.2
  7,      unmanaged,  Track.8,   61,      2.01
  8,      unmanaged,  Track.7,   61,      1.24
  9,      unmanaged,  Track.9,   81,      11.4
  10,     unmanaged,  Track.7,   61,      0.4

Notice that some Blocks have only a single forest type (blocks 1, 6, 7, 8, 9, 10) and therefore only one record. This means that 100% of the block is described by a single track, offset and area. Block 2 and block 3 on the other hand, are divided into both managed and unmanged types. Each of these blocks has two records so that the types can follow independent tracks.


Track labels are alphanumeric strings with no spaces or special characters other than the underscore ("_") or period ("."). There are no expectations about how the tracks are named.


When Patchworks starts, it will initialize the block structures with the area, track and offset values found in the block file. The default condition at startup time has no management treatments assigned to blocks, thus all blocks initially track along their original assignments for the entire planning horizon.