I'm using a shapefile in which polygons represent the geographic distribution of species. I need to calculate the combined range of several species sets, but the overlapping areas should be counted only once. My initial solution was to dissolve the polygons of the set of species of interest and then calculate its area. However, I must do this with more than 2000 sets of species and some of them have up to 10000 polygons, making the analysis take too long.
Is there another faster or more practical way of calculating the combined area of a set of polygons by counting overlapping areas only once?
For example, is there any way to delineate the outer contour of overlapping polygons?
I'm conducting these analyzes in R, but I'm willing to use other software if it decreases computational time considerably.