lsm_c_dcad() R function from [landscapemetrics]

DCAD (class level)

Disjunct core area density (core area metric)


lsm_c_dcad(
  landscape,
  directions = 8,
  consider_boundary = FALSE,
  edge_depth = 1
)

Arguments

landscape: A categorical raster object: SpatRaster; Raster* Layer, Stack, Brick; stars or a list of SpatRasters.
directions: The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).
consider_boundary: Logical if cells that only neighbour the landscape boundary should be considered as core
edge_depth: Distance (in cells) a cell has the be away from the patch edge to be considered as core cell

Returns

tibble

Details

DCAD = (\frac{\sum \limits_{j = 1}^{n} n_{ij}^{core}} {A}) * 10000 * 100

where $n_{ij}^{core}$ is the number of disjunct core areas and $A$

is the total landscape area in square meters.

DCAD is a 'Core area metric'. It equals the number of disjunct core areas per 100 ha relative to the total area. A disjunct core area is a 'patch within the patch' containing only core cells. A cell is defined as core area if the cell has no neighbour with a different value than itself (rook's case). The metric is relative and therefore comparable among landscapes with different total areas.

Because the metric is based on distances or areas please make sure your data is valid using check_landscape.

Units

Number per 100 hectares

Range

DCAD >= 0

Behaviour

Equals DCAD = 0 when DCORE = 0, i.e. no patch of class i contains a disjunct core area. Increases, without limit, as disjunct core areas become more present, i.e. patches becoming larger and less complex.

Examples


landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_dcad(landscape)

References

McGarigal K., SA Cushman, and E Ene. 2023. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical Maps. Computer software program produced by the authors; available at the following web site: https://www.fragstats.org

lsm_c_dcad function