Reportedly exert power, perhaps, over wooded country (5)
I believe the answer is:
weald
'wooded country' is the definition.
(I've seen this in another clue)
'reportedly exert' is the wordplay.
'reportedly' shows a homophone (sound like).
'exert' becomes 'wield' (synonyms).
'wield' is a homophone of 'WEALD'.
'power perhaps over' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for weald that I've seen before include "wooded area" , "Area of open or forested country" , "Open or wooded country" , "Fertile Kent area" , "ancient woodland" .)