lsm_c_mesh() R function from [landscapemetrics]

MESH (class level)

Effective Mesh Size (Aggregation metric)


lsm_c_mesh(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).

Returns

tibble

Details

MESH = \frac{\sum \limits_{j = 1}^{n} a_{ij} ^ 2} {A} * \frac{1} {10000}

where $a_{ij}$ is the patch area in square meters and $A$ is the total landscape area in square meters.

The effective mesh size is an 'Aggregation metric'. Because each patch is squared before the sums for each group i are calculated and the sum is standardized by the total landscape area, MESH is a relative measure of patch structure. MESH is perfectly, negatively correlated to lsm_c_division.

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

Units

Hectares

Range

cell size / total area <= MESH <= total area

Behaviour

Equals cellsize/total area if class covers only one cell and equals total area if only one patch is present.

Examples


landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_mesh(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

Jaeger, J. A. 2000. Landscape division, splitting index, and effective mesh size: new measures of landscape fragmentation. Landscape ecology, 15(2), 115-130.

lsm_c_mesh function