# lsm_l_prd: PRD (landscape level) In landscapemetrics: Landscape Metrics for Categorical Map Patterns

## Description

Patch richness density (Diversity metric)

## Usage

 1 lsm_l_prd(landscape, directions = 8) 

## Arguments

 landscape Raster* Layer, Stack, Brick, SpatRaster (terra), stars, or a list of rasterLayers. 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.

#### Units

Number per 100 hectares

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.

tibble

## References

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: http://www.umass.edu/landeco/research/fragstats/fragstats.html

## Examples

 1 lsm_l_prd(landscape) 

landscapemetrics documentation built on Sept. 5, 2021, 5:20 p.m.