Patch density (Aggregation metric)
lsm_l_pd(landscape, directions = 8)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).
$$PD = \frac{N} {A} * 10000 * 100$$ where \(N\) is the number of patches and \(A\) is the total landscape area in square meters.
PD is an 'Aggregation metric'. It describes the fragmentation the landscape, however,
does not necessarily contain information about the configuration or composition of the
landscape. In contrast to lsm_l_np it is standardized to the area and
comparisons among landscapes with different total area are possible.
Number per 100 hectares
0 < PD <= 1e+06
Increases as the landscape gets more patchy. Reaches its maximum if every cell is a different patch.
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_c_np,
lsm_l_ta,
lsm_c_pd