The best shield in the game for a warrior tank (aside from Partha, which is a better shield and also gets a set bonus with Kallak). If you rarely use a bow, you need a better warrior tank or you use Nathaniel Howe with the Howe Bow, it's wiser to make the shield instead of the bow.
The Landsmeet Shield can be more suitable for an Arcane Warrior set-up since it has nearly the same stats as the Heartwood shield, but it also grants 50 extra mana plus 30% protection against electricity. Elecricity also damages mana. Extra protection against mana is preferable over the nature protection the heartwood shield grants. If you have an Arcane Warrior as a tank the bow might be more preferable since the shield is redundant.
Quest: Heart of the Forest