Initial Landscape Composition

The ALCES® model requires geospatial data inputs to define the initial landscape composition of the study area in terms of the area of each landscape type, and area and length of each footprint type. A study area can be classified into up to 20 landscape types and 15 footprint types using a defined classification system.

Related inputs include the distribution of footprint types within landscape types and the stand age of forest types.

To run a simulation of future conditions, the initial composition of the landbase must be summarized and input into the model. If the land base composition prior to anthropogenic footprints is also of interest, this historical information may also be specified. ALCES uses a spatially stratified approach to track the area and length of each natural or agricultural landscape type (e.g., forest, cropland) and anthropogenic footprint type (e.g., wellsite, city). The definition of each cover type is user-defined, with a maximum of 20 landscape types and 15 footprint types permissible. Dividing the land base into many categories, or canisters, increases the range of potential analyses that are possible, but also increases the effort required to summarize the initial landscape composition and increases the number of input variables that must be specified throughout the model. Thus, a balance between amount of detail and modeling effort is required. Forest types may be further divided into age classes, and grassland types may be further divided into development stages. Since anthropogenic footprints are initially built upon natural or agricultural landscape types, the distribution of each footprint type among landscape types may be specified. Alternatively, it is possible to specify that footprints were distributed randomly among landscape types.

Table inputs

1. Initial area of landscape types
   - Enter the area (ha) of each landscape type at the start of the simulation period.
2. Initial area of footprint types
   - Enter the area (ha) of each land use footprint type at the start of the simulation period.
   - For each footprint type, enter '1' if the footprint is a linear development, '2' if it is not.
3. Initial length of landscape types
   - Enter the length (km) of edge associated with each landscape type at the start of the simulation period.  Landscape edge is defined as a boundary between: one landscape type and another landscape type; and between a landscape type and a footprint type.
   - Enter the length (km) of forest transitional edge at the start of the simulation period.  Forest transitional edge is typically defined as a boundary between two different age classes of the same forest type.
   - Enter the length (km) of natural permanent edge at the start of the simulation period.  Natural permanent edge is typically defined as the boundary between one landscape type and another landscape type.
4. Initial length of footprint types
   - Enter the length (km) of each land use footprint type at the start of the simulation period.  This includes the length of all linear developments (e.g., roads), and the perimeter of all non-linear developments (e.g., well sites).
5. Initial forest age class structure
   - For each forest type, enter the area (ha) in each age class at the start of the simulation period.  The combined area of all age classes must equal the area of the corresponding forest type entered in Table 1.  If it does not, the next simulation will abort and an error message will be given.  These values are recognized by the model only if the "Forest Even Age Class Structure Switch" at the bottom of this table is set to 0.
   - For the "Forest Even Age Class Structure Switch", enter '1' to divide each forest type into age classes that are all equal in area.  Enter '0' to use the values entered in the above rows of this table.
6. Number of years in each seral stage
   - Enter the number of years in each seral stage (age class) for each forest type.  For all forest types except plantations, the recommended seral stage width is 20 years.  (There are 10 seral stages.)  If plantations are assigned to a forest type, it is recommended that they be given a seral stage width of 5 years because they grow more quickly than other forest types.  These recommendations were made after conducting sensitivity analyses in ALCES that sought an optimal combination of accuracy and simulation speed.
7. Initial distribution of footprint types on landscape types
   - For each land use footprint type, enter the proportion (0 - 1) of the area of that footprint type that was originally built on a given landscape type.  These values are recognized by the model if the corresponding entry in Table 9 is zero.
8. Initial development stage and successional length
   - Enter the development stage (0 - 1) of non-forest landscape types at the start of the simulation period.
   - Enter the number of years to full recovery of each non-forest landscape type after a major perturbation.
9. Enter a 1 to place initial land use footprints randomly on landscape types
   - For each land use footprint type, enter '1' to set the initial distribution of footprints among landscape types in proportions equal to the proportion of each landscape type in the land base.  Enter '0' to use the values entered in Table 7.
10. Landscape and footprint classification code
    - Enter the classification code for each landscape type and footprint type.  Code values are as follows:
       1  Forest
       2  Grasslands
       3  Shrublands
       4  Wetlands
       5  Agriculture
       6  Moving Water
       7  Standing Water
       8  Non-vegetated landscape type
       9  Transportation
      10  Energy
      11  Residential
      12  Mining
      13  Other
11. Which landscape types represent native habitat?
    - Enter '1' if the listed landscape type represents native habitat.  Enter '0' if it does not.
12. Pre-settlement landscape composition and time period
    - Enter the relative area (proportion, 0 - 1) of each landscape type prior to the establishment of any land use footprints.  These values are recognized by the model if the Control Panel Switch "Initial landscape with user defined land use trajectories" is on.  This makes it possible to "grow" land use footprints such that by the end of the simulation, the land base has the same composition as that specified in Tables 1 and 2 for the initial land base.
    - Enter the number of years between the first establishment of land use footprints and the initial land base (e.g., present day)
    - Enter '1' to direct the model to recognize the proportions entered in this table.  Enter '0' to ignore them.
13. Average diameter of non-linear features
    - Enter the average diameter (m) of non-linear land use footprints.
14. Proportion of landscape types consisting of reclaimed land use footprints at time 0
    - Enter the proportion (0 - 1) of each landscape type that consists of land use footprints that were reclaimed prior to the start of the simulation period.
15. Defining LT to agricultural LT rules (0 through 5)
    - Enter the agricultural classification code for each landscape type and footprint type.  Code values are as follows:
       0  Not an agricultural cover type
       1  Cereal
       2  Oilseed
       3  Specialty
       4  Forage
       5  Pasture