Comic mostly wanders around trees in tropical regions (9)

'trees in tropical regions' is the definition.
(trees grown in tropical regions)

'comic mostly wanders' is the wordplay.
'comic' becomes 'manga' (type of Japanese comic).
'mostly' means to remove the last letter.
'wanders' becomes 'roves' ('rove' can be a synonym of 'wander').
'manga' with its final letter removed is 'mang'.
'mang'+'roves'='MANGROVES'

'around' is the link.