LSI (class level)

Landscape shape index (Aggregation metric)

Usage

lsm_c_lsi(landscape)

Arguments

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

Value

tibble

Details

$$LSI = \frac{e_{i}} {\min e_{i}}$$ where $e_{i}$ is the total edge length in cell surfaces and $\min e_{i}$ is the minimum total edge length in cell surfaces.

LSI is an 'Aggregation metric'. It is the ratio between the actual edge length of class i and the hypothetical minimum edge length of class i. The minimum edge length equals the edge length if class i would be maximally aggregated.

Units

None

Ranges

LSI >= 1

Behaviour

Equals LSI = 1 when only one squared patch is present or all patches are maximally aggregated. Increases, without limit, as the length of the actual edges increases, i.e. the patches become less compact.

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

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

Patton, D. R. 1975. A diversity index for quantifying habitat "edge". Wildl. Soc.Bull. 3:171-173.

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_lsi(landscape)
#> # A tibble: 3 × 6
#>   layer level class    id metric value
#>   <int> <chr> <int> <int> <chr>  <dbl>
#> 1     1 class     1    NA lsi     3.46
#> 2     1 class     2    NA lsi     3.87
#> 3     1 class     3    NA lsi     4.16