Source : Webster's Revised Unabridged Dictionary (1913)

Deforest \De*for"est\, v. t.
   To clear of forests; to disforest. --U. S. Agric. Reports.

Source : WordNet®

deforest
     v : remove the trees from; "The landscape was deforested by the
         enemy attacks" [syn: {disforest}, {disafforest}]