getAOO {redlistr}

Compute Area of Occupancy (AOO)

Description

getAOO determines the number of area of occupancy (AOO) grid cells occupied by a species or ecosystem. It includes capability for specifying whether at least one percent of the grid cell needs to be occupied before it is counted in the AOO. This functionality is important for assessing the IUCN Red List of Ecosystems Criteria B.

Usage

getAOO(input.data, grid.size, min.percent.rule = FALSE, percent = 1)

Arguments

input.data

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

grid.size

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

min.percent.rule

Logical. If TRUE, a minimum area threshold must be passed before a grid is counted as an AOO grid.

percent

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

Value

The number of grid cells occupied by the ecosystem or species

Author(s)

Nicholas Murray [e-mail], Calvin Lee [e-mail]

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(), getAOOSilent(), makeAOOGrid()

Examples

crs.UTM55S <- '+proj=utm +zone=55 +south +ellps=WGS84 +datum=WGS84 +units=m +no_defs'
r1 <- raster(ifelse((volcano<130), NA, 1), crs = crs.UTM55S)
extent(r1) <- extent(0, 6100, 0, 8700)
AOO <- getAOO(r1, 1000, min.percent.rule = TRUE, percent = 1)