Egmont National Park is important nationally because it contains a diverse range of vegetation that has developed in an environment of frequent volcanic activity. The vegetation ranges from semi-coastal and montane forest to tussocklands, alpine and scree communities. The vegetation changes in a remarkably short rise in altitude compared to other places.The area's high rainfall and mild coastal climate has allowed a lush rainforest to develop. However its nature changes the higher you go on the mountain - from tall rimu and kamahi trees at lower altitudes through dense subalpine shrubs to an alpine herbfield with some plants unique to the park.The forests of the park are composed of native conifer and broadleaved tree species, with beech trees notably absent. Other outstanding features are the large number of northern rata trees and one of the most extensive kahikatea-rimu-kāmahi semi-swamp forests in the North Island.