lsm_p_cai: CAI (patch level)

In landscapeecology/landscapemetrics: Landscape Metrics for Categorical Map Patterns

CAI (patch level)

Description

Core area index (Core area metric)

Usage

lsm_p_cai(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

Details

CAI = (\frac{a_{ij}^{core}} {a_{ij}}) * 100

where a_{ij}^{core} is the core area in square meters and a_{ij} is the area in square meters.

CAI is a 'Core area metric'. It equals the percentage of a patch that is core area. A cell is defined as core area if the cell has no neighbour with a different value than itself (rook's case). It describes patch area and shape simultaneously (more core area when the patch is large and the shape is rather compact, i.e. a square). Because the index is relative, it is comparable among patches with different area.

Units

Percent

Range

0 <= CAI <= 100

Behaviour

CAI = 0 when the patch has no core area and approaches CAI = 100 with increasing percentage of core area within a patch.

Value

tibble

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

See Also

lsm_p_core, lsm_p_area,
lsm_c_cai_mn, lsm_c_cai_sd, lsm_c_cai_cv, lsm_c_cpland,
lsm_l_cai_mn, lsm_l_cai_sd, lsm_l_cai_cv

Examples

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

landscapeecology/landscapemetrics documentation built on April 7, 2024, 11:11 p.m.