Notice a tree changed, included being made effervescent (7)
I believe the answer is:
aerated
'made effervescent' is the definition.
(I've seen this in another clue)
'notice a tree changed included' is the wordplay.
'notice' becomes 'ad' (both can mean an advertisement).
'changed' indicates an anagram.
'included' is an insertion indicator.
'a'+'tree'='atree'
'atree' is an anagram of 'erate'.
'ad' enclosing 'erate' is 'AERATED'.
'being' is the link.
(Other definitions for aerated that I've seen before include "As pop is" , "Mixed with air" , "at boiling point?" , "Descriptive of soda-water" , "Ventilated" .)