Creates Extent of occurrence (EOO) Polygon

makeEOO is a generic function that creates a minimum convex polygon enclosing all occurrences of the ecosystems provided in the input data. If the input provided is a raster layer, the points are taken from a buffer that has the radius of half of the shorter edge of the pixel around the centroid.

Usage

makeEOO(input_data, names_from)

Arguments

input_data: Spatial object of an ecosystem or species distribution. Please use a CRS with units measured in metres.
names_from: name of the column containing ecosystem names. If missing all features will be analysed together. Only needed for vector data.

Value

An object of class sf representing the EOO of input_data, or a list of sf objects if multiple ecosystems were input. Also inherits its CRS from input_data.

References

IUCN 2024. Guidelines for the application of IUCN Red List of Ecosystems Categories and Criteria, Version 2.0. Keith, D.A., Ferrer-Paris, J.R., Ghoraba, S.M.M., Henriksen, S., Monyeki, M., Murray, N.J., Nicholson, E., Rowland, J., Skowno, A., Slingsby, J.A., Storeng, A.B., Valderrábano, M. & Zager, I. (Eds.) Gland, Switzerland: IUCN. ix + 94pp. https://doi.org/10.2305/CJDF9122

Author

Nicholas Murray murr.nick@gmail.com, Calvin Lee calvinkflee@gmail.com

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")
     EOO.polygon <- makeEOO(r1)
  }, silent = TRUE)
}