landscapemetrics (version 2.1.4)

lsm_l_cai_mn: CAI_MN (landscape level)

Description

Mean of core area index (Core area metric)

Usage

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

Value

tibble

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

$$CAI_{MN} = mean(CAI[patch_{ij}]$$ where \(CAI[patch_{ij}]\) is the core area index of each patch.

CAI_MN is a 'Core area metric'. The metric summarises the landscape as the mean 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).

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

Units

Percent

Range

0 <= CAI_MN <= 100

Behaviour

CAI_MN = 0 when all patches have no core area and approaches CAI_MN = 100 with increasing percentage of core area within patches.

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_cai, mean,
lsm_c_cai_sd, lsm_c_cai_sd, lsm_c_cai_cv,
lsm_l_cai_sd, lsm_l_cai_cv

Examples

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