Mean of core area index (Core area metric)
lsm_l_cai_mn(
landscape,
directions = 8,
consider_boundary = FALSE,
edge_depth = 1
)tibble
Raster* Layer, Stack, Brick, SpatRaster (terra), stars, or a list of rasterLayers.
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
$$CAI_{MN} = mean(CAI[patch_{ij}]$$ 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).
Percent
0 <= CAI_MN <= 100
CAI_MN = 0 when all patches have no core area and approaches CAI_MN = 100 with increasing percentage of core area within patches.
McGarigal, K., SA Cushman, and E Ene. 2012. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical and Continuous Maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at the following web site: https://www.umass.edu/landeco/
lsm_p_cai,
mean,
lsm_c_cai_sd,
lsm_c_cai_sd,
lsm_c_cai_cv,
lsm_l_cai_sd,
lsm_l_cai_cv