Coefficient of variation of core area index (Core area metric)
lsm_l_cai_cv(
landscape,
directions = 8,
consider_boundary = FALSE,
edge_depth = 1
)
tibble
A categorical raster object: SpatRaster; Raster* Layer, Stack, Brick; stars or a list of SpatRasters.
The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).
Logical if cells that only neighbour the landscape boundary should be considered as core
Distance (in cells) a cell has the be away from the patch edge to be considered as core cell
$$CAI_{CV} = cv(CAI[patch_{ij}]$$ where \(CAI[patch_{ij}]\) is the core area index of each patch.
CAI_CV is a 'Core area metric'. The metric summarises the landscape as the Coefficient of variation of the core area index of all patches in the landscape. The core area index is the percentage of core area in relation to patch area. A cell is defined as core area if the cell has no neighbour with a different value than itself (rook's case). The metric describes the differences among all patches in the landscape. Because it is scaled to the mean, it is easily comparable.
Because the metric is based on distances or areas please make sure your data
is valid using check_landscape
.
Percent
CAI_CV >= 0
Equals CAI_CV = 0 if the core area index is identical for all patches. Increases, without limit, as the variation of the core area indices increases.
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_p_cai
,
lsm_c_cai_mn
,
lsm_c_cai_sd
,
lsm_c_cai_cv
,
lsm_l_cai_mn
,
lsm_l_cai_sd
landscape <- terra::rast(landscapemetrics::landscape)
lsm_l_cai_cv(landscape)
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