The most common and most likely answer to this crossword clue is the 8 letter word FORESTER
I've seen this crossword clue in The Daily Telegraph
F
O
R
E
S
T
E
R
More clues leading to the result FORESTER
Buddy explains!
The straight part
We know that "One in favour of trees being replanted?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one in favour of trees being replanted? = forester.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FORESTER mean?
FORESTER noun- A person who practices forestry.
- A person who lives in a forest.
- A moth in the family Zygaenidae.
- Any of various nymphalid butterflies of the genus Lethe. Other members of this genus are called tree browns and wood browns.