Zechariah the prophet declared,

Open your doors, O Lebanon,
That fire may devour your cedars.
Wail, O cypress, for the cedar has fallen,
Because the mighty trees are ruined.
Wail, O oaks of Bashan,
For the thick forest has come down.
There is the sound of wailing shepherds!
For their glory is in ruins.
There is the sound of roaring lions!
For the pride of the Jordan is in ruins.
(Zechariah 11.1–3)

Scripture often highlights the glory of the cedars of Lebanon. Solomon used them in the construction of the temple. Their height is used in Amos 2.9 to picture the height of the Amorites, whom the ten spies said made them look like grasshoppers.

Their representation in Zechariah 11, seems to be the same, that of someone exalted, and Lebanon opens itself up to allow invading armies to use its vast forest for the attack on Jerusalem.

With Jerusalem destroyed, the glory of the shepherds of Israel is destroyed.

Something like this happened in the Roman invasion of Jerusalem when the Romans cut down forests to use in the attack against the walls of Jerusalem. Whether Zechariah prophesies of this in particular is open for further discussion.