arborist

from WordNet (r) 3.0 (2006)

arborist
    n 1: a specialist in treating damaged trees [syn: {tree
         surgeon}, {arborist}]

from The Collaborative International Dictionary of English v.0.48

Arborist \Ar"bor*ist\, n. [F. arboriste, fr. L. arbor tree.]
   One who makes trees his study, or who is versed in the
   knowledge of trees. --Howell.
   [1913 Webster]