Core area percentage of landscape (Core area metric)
lsm_c_cpland(
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
$$CPLAND = (\frac{\sum \limits_{j = 1}^{n} a_{ij}^{core}} {A}) * 100$$ where \(a_{ij}^{core}\) is the core area in square meters and \(A\) is the total landscape area in square meters.
CPLAND is a 'Core area metric'. It is the percentage of core area of class i in relation to the total landscape area. A cell is defined as core area if the cell has no neighbour with a different value than itself (rook's case). Because CPLAND is a relative measure, it is comparable among landscapes with different total areas.
Percentage
0 <= CPLAND < 100
Approaches CPLAND = 0 if CORE = 0 for all patches. Increases as the amount of core area increases, i.e. patches become larger while being rather simple in shape.
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_core and lsm_l_ta