Brown tiles (dirt?) have been steadily accumulating around my claim, which is situated on green grassland. I was wondering what causes this. I could've sworn I'd read something about it before, but it's difficult to come up with an appropriate search term (besides "dirt" or "brown stuff").

Could it be my livestock eating the grass? If so, how long does grass take to re-grow? My animals won't eventually run out of grass to eat, will they? I am not spending every other hour filling troughs that get empty faster than Flash Gordan's bowels after a bad curry.
Ty
