currently when you dig a tile and turn it into raw dirt it will eventually "decay" by turning into the biome next to it.
let us "dig" a tile of biome and carry it like a bush, this would allow folks to do more advanced landscaping and biome manipulation by bringing back a few tiles of sod from that biome and slowly growing it larger, would allow towns to make an oasis in the badlands. more decorative tile options for carebears etc.