Conservative valley landscape receiving constant restoration (13)
I believe the answer is:
convalescence
'restoration' is the definition.
'conservative valley landscape receiving constant' is the wordplay.
'conservative' becomes 'con' (I've seen this in other clues).
'valley' becomes 'vale' ('vale' can be a synonym of 'valley').
'landscape receiving' becomes 'scenc' (I can't explain this - if you can you should give a lot more credence to this answer).
'constant' becomes 'e' (mathematics: c.7s).
'con'+'vale'+'scenc'+'e'='CONVALESCENCE'
Can you help me to learn more?
(Other definitions for convalescence that I've seen before include "(Time of) gradual recovery of health" , "on the way to recovery" , "Recovery of health and strength" , "Recuperation (from illness)" , "Period of recovery from illness" .)