redlistr (version 2.1.0)

makeAOOGrid: Create Area of Occupancy (AOO) grid for an ecosystem or species distribution

Description

makeAOOGrid is a generic function that creates grids representing the area of occupancy for distributions based on the input spatial data. It includes capability for specifying whether the least occupied cells collectively containing less than 1% of the ecosystem are counted in the AOO. This functionality is important for assessing the IUCN Red List of Ecosystems Criteria B.

Usage

makeAOOGrid(
  input_data,
  cell_size = 10000,
  names_from = NA,
  bottom_1pct_rule = TRUE,
  percent = 1,
  jitter = 150,
  n_jitter = 35
)

Value

A shapefile of grid cells occupied by an ecosystem or species, or a list of these if multiple ecosystems were input.

Arguments

input_data

Spatial object (sf or SpatRaster) of an ecosystem or species distribution. Please use a CRS with units measured in metres.

cell_size

A number specifying the width of the desired grid square (in same units as your coordinate reference system)

names_from

the name of the column containing ecosystem labels

bottom_1pct_rule

Logical. If TRUE, grid cells containing the least ecosystem area are dropped up to 1% of the total distribution.

percent

Numeric. The minimum percent to be applied as a threshold for the bottom_1pct_rule

jitter

Integer. 0 = do not jitter, 1 = force jitter, another number indicates conditional jitter, the number of AOO cells under which to jitter, and over which not to jitter the grid.

n_jitter

the number of grids to test for ecosystems near the AOO thresholds. Ignored if jitter = FALSE.

Author

Nicholas Murray , Calvin Lee , Aniko B. Toth

References

Bland, L.M., Keith, D.A., Miller, R.M., Murray, N.J. and Rodriguez, J.P. (eds.) 2016. Guidelines for the application of IUCN Red List of Ecosystems Categories and Criteria, Version 1.0. Gland, Switzerland: IUCN. ix + 94pp. Available at the following web site: https://iucnrle.org/

See Also

Other AOO functions: createGrid(), getAOO(), jplot(), top_pct()

Examples

if (requireNamespace("terra", quietly = TRUE)) {
  ok <- try({
      m <- matrix(sample(1:4, 500, replace = TRUE, prob = c(4,1,1,6)), nrow=25, ncol=20)
      r1 <- terra::rast(m, crs = "+proj=utm +zone=55 +south +datum=WGS84 +units=m +no_defs")
      AOO_grid <- makeAOOGrid(r1, cell_size = 3)
  }, silent = TRUE)
}