RPD (landscape level)

Relative patch richness (Diversity metric)

Usage

lsm_l_rpr(landscape, classes_max = NULL, verbose = TRUE)

Arguments

landscape

A categorical raster object: SpatRaster; Raster* Layer, Stack, Brick; stars or a list of SpatRasters.

classes_max

Potential maximum number of present classes

verbose

Print warning message if not sufficient patches are present

Value

tibble

Details

$$RPR = \frac{m} {m_{max}} * 100$$ where \(m\) is the number of classes and \(m_{max}\) is the (theoretical) maximum number of classes.

RPR is an 'Diversity metric'. The metric calculates the percentage of present classes in the landscape in relation to a (theoretical) number of maximum classes. The user has to specify the maximum number of classes. Note, that if classes_max is not provided, the functions returns NA.

Units

Percentage

Ranges

0 < RPR <= 100

Behaviour

Approaches RPR > 0 when only one class type is present, but the maximum number of classes is large. Equals RPR = 100 when m = m_max

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

Romme, W. H. 1982. Fire and landscapediversity in subalpine forests of Yellowstone National Park.Ecol.Monogr. 52:199-221

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_l_rpr(landscape, classes_max = 5)
#> # A tibble: 1 × 6
#>   layer level     class    id metric value
#>   <int> <chr>     <int> <int> <chr>  <dbl>
#> 1     1 landscape    NA    NA rpr       60