In general, trees represent the deepest and most significant intellectual concepts: the ones that come to us most directly from the Lord. This varies depending on us and our states: the people of the Most Ancient Church, who were in a state of loving the Lord, understood truth automatically and internally through what the Writings call "perception"; people in lower states (including most of us) have to work a little harder to learn it from the Word and by willing to follow the Lord. In other parts of the Bible, especially in the prophets and New Testament parables, the meaning of "tree" is broader, meaning not just a person's intellectual concepts but the whole person.

'Trees,' as in Joel 1:10-12, signify knowledges.

148. In the heavens all dwell in separate groups in accordance with the quarters. Those who are in the good of love dwell towards the east and the west, those who are in clear perception of it towards the east, and those in obscure perception of it towards the west. Those who are in wisdom from the good of love dwell towards the north and south, those who are in the clear light of wisdom towards the south, and those in obscure light of it towards the north. The angels of the Lord's spiritual kingdom and those of His celestial kingdom dwell in the same order, yet differently in so far as their good of love and light of truth from good differ. For, in the celestial kingdom the love is love to the Lord, and the light of truth therefrom is wisdom, while in the spiritual kingdom, the love is love towards the neighbour, which is called charity, and the light of truth therefrom is intelligence which is also called faith (see above 23). They differ also as to the quarters, for the quarters in the two kingdoms are apart from each other by thirty degrees, as has been said just above (146).