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MSIDI (landscape level)

Source: R/lsm_l_msidi.R
lsm_l_msidi.Rd

Modified Simpson's diversity index (Diversity metric)

Usage

lsm_l_msidi(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

$$MSIDI = -\ln \sum \limits_{i = 1}^{m} P_{i}^{2}$$ where \(P_{i}\) is the landscape area proportion of class i.

MSIDI is a 'Diversity metric'.

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

Units

None

Range

MSIDI >= 0

Behaviour

MSIDI = 0 if only one patch is present and increases, without limit, as the amount of patches with equally distributed landscape proportions increases

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

Simpson, E. H. 1949. Measurement of diversity. Nature 163:688

Pielou, E. C. 1975. Ecological Diversity. Wiley-Interscience, New York.

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

See also

lsm_l_sidi

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_l_msidi(landscape)
#> # A tibble: 1 × 6
#>   layer level     class    id metric value
#>   <int> <chr>     <int> <int> <chr>  <dbl>
#> 1     1 landscape    NA    NA msidi  0.926