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Adds a boundary or zone constraint to a scenario object

Source: R/add_constraint.R
add_constraint_boundary.Rd

The purpose of boundary constraints is to limit a future projection within a specified area (such as for example a range or ecoregion). This can help to limit unreasonable projections into geographic space.

When method = "zone" is used, the constraint is applied per projection timestep as a mask on the suitability output (before any threshold is computed), rather than posthoc on the full stacked result. This allows other per-timestep constraints (e.g. dispersal) to interact with the zone at each step. Zones can be either static (one layer applied identically at every timestep) or time-series (one layer per timestep, matched by nearest date).

Note: Setting a boundary constraint for future projections effectively potentially clips suitable areas!

Usage

add_constraint_boundary(mod, layer, ...)

# S4 method for class 'BiodiversityScenario,sf'
add_constraint_boundary(mod, layer, method = "boundary", ...)

# S4 method for class 'BiodiversityScenario,ANY'
add_constraint_boundary(mod, layer, method = "boundary", ...)

Arguments

mod

A BiodiversityScenario object with specified predictors.

layer

For method = "boundary": a single-layer SpatRaster or sf object. Has to be binary. For method = "zone": must be a SpatRaster. A single-layer raster is used as a static zone (same mask at every timestep). A multi-layer raster is treated as a time-series zone; layers are matched to projection timesteps either by the raster's time attribute (terra::has.time(layer) == TRUE, nearest date selected) or, when no time attribute is present, by layer order (terra::nlyr(layer) must equal the number of covariate timesteps).

...

passed on parameters. See also the specific methods for adding constraints.

method

A character specifying the constraint type. Either "boundary" (default, posthoc mask on full stacked projection) or "zone" (per-timestep mask applied within the projection loop).

See also

Other constraint: add_constraint(), add_constraint_MigClim(), add_constraint_adaptability(), add_constraint_connectivity(), add_constraint_dispersal(), add_constraint_minsize(), add_constraint_threshold(), simulate_population_steps()

Examples

if (FALSE) { # \dontrun{
# Static boundary constraint (posthoc)
scenario(fit) |> add_constraint_boundary(range)

# Static zone constraint (per-timestep)
scenario(fit) |> add_constraint_boundary(range, method = "zone")

# Time-series zone: SpatRaster with terra::time() set
scenario(fit) |> add_constraint_boundary(zone_raster, method = "zone")

} # }