Made 'em for you, didn't I? Of course you can use them. I'll probably use them myself, but any stock I share here that I've made is under terms where you can use in your own maps for personal and commercial use, just not resell the stock itself. If you use Clip Studio Paint you can even have them set up for that program. Although I see by that example you meant something more like an open expanse of forest. I've never seen brushes that really do that.