Layout of trees not saying much (5)
I believe the answer is:
terse
'not saying much' is the definition.
(I've seen this in another clue)
'layout of trees' is the wordplay.
'layout of' indicates anagramming the letters.
'trees' anagrammed gives 'TERSE'.
(Other definitions for terse that I've seen before include "Curtly brief" , "Brusque and curt" , "Short and sharp" , "Short and to the point" , "Crisp and brief" .)