Skip to contents

PD (class level)

Source: R/lsm_c_pd.R
lsm_c_pd.Rd

Patch density (Aggregation metric)

Usage

lsm_c_pd(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).

Value

tibble

Details

$$PD = \frac{n_{i}} {A} * 10000 * 100$$ where \(n_{i}\) is the number of patches and \(A\) is the total landscape area in square meters.

PD is an 'Aggregation metric'. It describes the fragmentation of a class, however, does not necessarily contain information about the configuration or composition of the class. In contrast to lsm_c_np it is standardized to the area and comparisons among landscapes with different total area are possible.

Units

Number per 100 hectares

Ranges

0 < PD <= 1e+06

Behaviour

Increases as the landscape gets more patchy. Reaches its maximum if every cell is a different patch.

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

See also

lsm_c_np, lsm_l_ta,
lsm_l_pd

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_pd(landscape)
#> # A tibble: 3 × 6
#>   layer level class    id metric  value
#>   <int> <chr> <int> <int> <chr>   <dbl>
#> 1     1 class     1    NA pd     10000 
#> 2     1 class     2    NA pd     14444.
#> 3     1 class     3    NA pd      6667.