Standard deviation of patch area (Area and edge metric)
lsm_c_area_sd(landscape, directions =8)
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).
Returns
tibble
Details
AREASD=sd(AREA[patchij])
where AREA[patchij] is the area of each patch in hectares.
AREA_SD is an 'Area and Edge metric'. The metric summarises each class as the standard deviation of all patch areas belonging to class i. The metric describes the differences among patches of the same class i in the landscape.
Because the metric is based on distances or areas please make sure your data is valid using check_landscape.
Units
Hectares
Range
AREA_SD >= 0
Behaviour
Equals AREA_SD = 0 if all patches are identical in size. Increases, without limit, as the variation of patch areas 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