lsm_l_prd: PRD (landscape level)

In landscapemetrics: Landscape Metrics for Categorical Map Patterns

PRD (landscape level)

Description

Patch richness density (Diversity metric)

Usage

lsm_l_prd(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).

Details

PRD = \frac{m} {A} * 10000 * 100

where m is the number of classes and A is the total landscape area in square meters.

PRD is a 'Diversity metric'. It is one of the simplest diversity and composition measures. In contrast to lsm_l_pr, it is a relative measure and following, comparable among landscapes with different total landscape areas.

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

Units

Number per 100 hectares

Range

PR > 0

Behaviour

Approaches PRD > 1 when only one patch is present and the landscape is rather large. Increases, without limit, as the number of classes increases and the total landscape area decreases.

Value

tibble

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_l_prd(landscape)

landscapemetrics documentation built on Sept. 12, 2024, 7:42 a.m.