Green meadow on forestry boundaries (5)
I believe the answer is:
leafy
'green' is the definition.
(thesaurus)
'meadow on forestry boundaries' is the wordplay.
'meadow' becomes 'lea' (I've seen this before).
'on' is a charade indicator (letters next to each other).
'boundaries' suggests removing the centre (only the edge or boundary letters remain).
'forestry' with its centre taken out is 'fy'.
'lea'+'fy'='LEAFY'
(Other definitions for leafy that I've seen before include "Like the better class suburbs?" , "With lots of foliage" , "Epithet applied to suburbs" , "more shady places?" , "Green" .)