# Quantification of the range size of a species using habitat suitability maps and IUCN criteria) This function quantifies the range size of a species using standard IUCN criteria (Area of Occupancy AOO, Extent of Occurence EOO) or binary maps derived from Species Distribution Models. ```r ecospat.rangesize (bin.map, ocp, buffer, eoo.around.model, eoo.around.modelocp, xy, EOO, Model.within.eoo, AOO, resol, AOO.circles, d, lonlat, return.obj, save.obj, save.rangesize, directory) ecospat.rangesize (bin.map = NULL, ocp = TRUE, buffer = 0, eoo.around.model = TRUE, eoo.around.modelocp = FALSE, xy = NULL, EOO = TRUE, Model.within.eoo = TRUE, AOO = TRUE, resol = c(2000, 2000), AOO.circles = FALSE, d = sqrt((2000 * 2)/pi), lonlat = FALSE, return.obj = TRUE, save.obj = FALSE, save.rangesize = FALSE, directory = getwd()) ``` ## Arguments - `bin.map`: Binary map (a SpatRaster) from a Species Distribution Model. - `ocp`: logical. Calculate occupied patch models from the binary map (predicted area occupied by the species) - `buffer`: numeric. Calculate occupied patch models from the binary map using a buffer (predicted area occupied by the species or within a buffer around the species, for details see ?extract). - `eoo.around.model`: logical. The EOO around all positive predicted values from the binary map. - `eoo.around.modelocp`: logical. EOO around all positive predicted values of occupied patches. - `xy`: xy-coordinates of the species presence - `EOO`: logical. Extent of Occurrence. Convex Polygon around occurrences. - `Model.within.eoo`: logical. Area predicted as suitable by the model within EOO. - `AOO`: logical. Area of Occupancy ddervied by the occurrences. - `resol`: Resolution of the grid frame at which AOO should be calculated. - `AOO.circles`: logical. AOO calculated by circles around the occurrences instead of using a grid frame. - `d`: Radius of the AOO.circles around the occurrences. - `lonlat`: Are these longitude/latidue coordinates? (Default = FALSE). - `return.obj`: logical. should the objects created to estimate range size be returned (SpatRaster and spatial polygons). Default: TRUE - `save.obj`: logical. should objects be saved on hard drive? - `save.rangesize`: logical. should range size estimations be saved on hard drive . - `directory`: directory in which objects should be saved (Default = getwd()) ## Details The range size of a species is important for many conservation purposes, e.g. to assess the status of threat for IUCN Red Lists. This function quantifies the range size using different IUCN measures, i.e. the Area Of Occupancy (AOO), the Extent Of Occurrence (EOO) and from binary maps derived from Species Distribution Models (SDMs). Different ways to extract range size from SDMs are available, e.g. using occupied patches, the suitable habitat within EOO or a convex hull around the suitable habitat. ## Returns A list with the values of range size quantification and the stored objects used for quantification (of class SpatRaster, ahull, ConvexHull). ## Author(s) Frank Breiner frank.breiner@wsl.ch with the contributions of Flavien Collart ## References IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1. Second edition. Gland, Switzerland and Cambridge, UK: IUCN. iv + 32pp. IUCN Standards and Petitions Subcommittee. 2016. Guidelines for Using the IUCN Red List Categories and Criteria. Version 12. Prepared by the Standards and Petitions Subcommittee. Downloadable from http://www.iucnredlist.org/documents/RedListGuidelines.pdf Pateiro-Lopez, B., and A. Rodriguez-Casal. 2010. Generalizing the Convex Hull of a Sample: The R Package alphahull. **Journal of Statistical software**, 34 , 1-28. ## See Also `ecospat.occupied.patch`, `ecospat.mpa`, `ecospat.binary.model` ## Examples ```r library(terra) library(dismo) # coordinates of the plots xy <- ecospat.testData[,2:3] # environmental data predictors <- terra::rast(system.file("extdata","ecospat.testEnv.tif",package="ecospat")) env <- terra::extract(predictors,xy,ID=FALSE) spData <- cbind.data.frame(occ=ecospat.testData$Veronica_alpina,env) mod <- glm(occ~ddeg0+I(ddeg0^2)+srad68+I(srad68^2),data=spData,family = binomial()) # predict to entire dataset pred <- terra::predict(predictors,mod,type="response") plot(pred) points(xy[spData$occ==1,]) ### make binary maps #arbitratry threshold pred.bin.arbitrary <- ecospat.binary.model(pred,0.3) names(pred.bin.arbitrary) <- "me.arbitrary" # use MPA to convert suitability to binary map mpa.cutoff <- ecospat.mpa(pred,xy[spData$occ==1,]) pred.bin.mpa <- ecospat.binary.model(pred,mpa.cutoff) names(pred.bin.mpa) <- "me.mpa" ### rangesize calculations if(require(alphahull,quietly=TRUE)){ rangesize2 <- ecospat.rangesize(c(pred.bin.mpa,pred.bin.arbitrary), xy=xy[spData$occ==1,], AOO.circles = TRUE, lonlat =FALSE) rangesize2$RangeSize names(rangesize2$RangeObjects) par(mfrow=c(1,3)) plot(ecospat.binary.model(pred,0),legend=FALSE, main="IUCN criteria") ### IUCN criteria & derivates # plot AOO plot(rangesize2$RangeObjects$AOO,add=TRUE, col="red",legend=FALSE) # plot EOO plot(rangesize2$RangeObjects$EOO@polygons,add=TRUE, border="red", lwd=2) # plot circles around occurrences plot(rangesize2$RangeObjects$AOO.circle@polygons,add=TRUE,border="blue") for(i in 1:2){ ## plot the occupied patches of the model plot(rangesize2$RangeObjects$models.ocp[[i]],col=c("grey","blue","darkgreen"), main=names(rangesize2$RangeObjects$models.ocp[[i]]),legend=FALSE) points(xy[spData$occ==1,],col="red",cex=0.5,pch=19) ## plot EOO around model plot(rangesize2$RangeObjects$eoo.around.model[[i]]@polygons,add=TRUE,border="blue",lwd=2) ## plot the modeled area within EOO #plot(rangesize$RangeObjects$model.within.eoo[[i]],col=c("grey","blue","darkgreen")) #points(occ,col="red",cex=0.5,pch=19) #plot(rangesize$RangeObjects$EOO@polygons,add=TRUE, border="red", lwd=2) } par(mfrow=c(1,1)) ### Alpha-hulls are not included in the function yet because of Licence limitations. ### However, alpha-hulls can easily be included manually (see also the help file of ### the alpha hull package): alpha = 2 # alpha value of 2 recommended by IUCN del<-alphahull::delvor(xy[spData$occ==1,]) dv<-del$mesh mn <- mean(sqrt(abs(del$mesh[,3]-del$mesh[,5])^2+abs(del$mesh[,4]-del$mesh[,6])^2))*alpha alpha.hull<-alphahull::ahull(del,alpha=mn) #Size of alpha-hulls #areaahull(alpha.hull) #works but uses a deprecated function in alphahull 2.1 #plot alphahulls plot(rangesize2$RangeObjects$models.ocp[[1]],col=c("grey","blue","darkgreen"), main=names(rangesize2$RangeObjects$models.ocp[[1]]),legend=FALSE) plot(alpha.hull,add=TRUE,lwd=1) } ```

ecospat.rangesize function