As the area warmed, much of the podocarp forest was displaced by Myrtaceae such as pōhutukawa and Ascarina lucida. Prior to human settlement, much of the isthmus was covered in broadleaf tree forests, predominantly Beilschmiedia tarairi (taraire) and Vitex lucens (pūriri) trees.
As temperatures increased, the podocarp forest gave way to Myrtaceae like pōhutukawa and Ascarina lucida. Before human settlement, the isthmus was primarily covered by broadleaf tree forests composed of Beilschmiedia tarairi (taraire) and Vitex lucens (pūriri) trees.