One. They stuck a massive fort out in the wilds. Not too dissimilar from sticking a big city somewhere. It has shops, healers, stone walls etc. You can bet that the wild creature who lived where it now stands had to find somewhere else. A fortress also requires supplies, causing heavy traffic through the wilds, and has waste, likely causing some pollution.

Two. They have conjurers. One of their leaders (Elrys) is a conjurer. Remember why sylvans went to war with warlocks? The fortress has also accepted drow in the past.