The Collaborative International Dictionary of English v.0.48:
Reforest \Re*for"est\, v. t. [imp. & p. p. Reforested; p. pr. & vb. n. Reforesting.] To replant with trees; to reafforest; to reforestize. [Webster 1913 Suppl.]WordNet (r) 3.0 (2006):
reforest v 1: forest anew; "After the fire, they reforested the mountain"