Skip to contents

Mean of core area (Core area metric)

Usage

lsm_c_core_mn(
  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

Value

tibble

Details

$$CORE_{MN} = mean(CORE[patch_{ij}])$$ where \(CORE[patch_{ij}]\) is the core area in square meters of each patch.

CORE_MN is a 'Core area metric' and equals the mean of core areas of all patches belonging to class i. The core area is defined as all cells that have no neighbour with a different value than themselves (rook's case).

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

Units

Hectares

Range

CORE_MN >= 0

Behaviour

Equals CORE_MN = 0 if CORE = 0 for all patches. Increases, without limit, as the core area indices increase.

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

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_core_mn(landscape)
#> # A tibble: 3 × 6
#>   layer level class    id metric     value
#>   <int> <chr> <int> <int> <chr>      <dbl>
#> 1     1 class     1    NA core_mn 0.000844
#> 2     1 class     2    NA core_mn 0.000685
#> 3     1 class     3    NA core_mn 0.0039