The largest trees are typically emergent podocarps, rimu, kahikatea, miro, matai, totara densely stocked on recent pumice, alluvial and glacial soils, and emergent but more sparsely stocked on older, usually hill-country sites. Forest type and class structure varies according to species composition, altitude, topography, soil type, climate, and historical disturbance. Five taxa of beech are currently recognised in New Zealand. These comprise four species, one of which has two varieties. The beech can reach a reasonable size, the largest being red beech recorded up to 42.7 m in height, with a trunk 3.0 m in diameter.
Growth form varies considerably between species, altitude and site conditions.
The beech species are adapted to growing on low fertility and poorly drained soils, dry sites such as ridge crests, and areas of recent disturbance. They often form extensive, relatively uniform forests in the montane region, but at lower altitudes give way to the more competitive hardwoods and softwoods. The beech species tend to form discrete pure stands rather than occur in intricate mixtures with other tree genera. This may be related to mycorrhizal symbionts. Beech forest occurs almost throughout the full latitudinal range of the North and South Islands, though its distribution in the north-west tends to be local.