The Collaborative International Dictionary of English v.0.48:

Appreciative \Ap*pre"ci*a*tive\, a.
   Having or showing a just or ready appreciation or perception;
   as, an appreciative audience. -- Ap*pre"ci*a*tive*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

appreciatively
    adv 1: with appreciation; in a grateful manner; "he accepted my
           offer appreciatively" [syn: appreciatively,
           gratefully] [ant: unappreciatively, ungratefully]