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Podocarp forests of south-west New Zealand
The south-west New Zealand podocarp forest primarily occurs on valley floors and lowlands in mild wet areas west of the main S Island divide. Rainfall is 5-10 m per year with no pronounced dry season. Consequently, soil moisture varies from ample to excessive. At higher and colder sites (above about 500 m elevation) the podocarp forest is transitional to a Nothofagus (Antarctic beech) forest (1).
The dominant trees form an uneven canopy above a dense understory. Lianas and creepers cover the trees. The ground is thickly covered in ferns and mosses. Overstory dominance is controlled largely by substrate variation. The most common dominant, rimu (Dacrydium cupressinum), forms extensive stands on podsol soils of glacial outwash and marine terraces, such as those seen in Waitutu, the South Okarito and Waikukapa forests. Kahikatea (Podocarpus dacrydioides) forests are only found in fertile lowlands. These once covered large areas, but are now reduced to less than 5000 ha. Additional canopy dominants include matai (Prumnopitys taxifolia), totara (Podocarpus totara), and miro (Prumnopitys ferruginea). Subcanopy dominants include the angiosperms kapuka (Griselinea litoralis), kamahi (Wienmania racemosa), kotukutuku (Fuchsia excorticata), peppertree (Psudowintera colorata), five finger (Neopanax arboreum), mahoe (Melicytus ramiflorus), and tarata (Pitosporum eugenoides); and the tree ferns Dicksonia squarrosa, Cyathea medullaris, and Cyathea smithii (2).
The podocarp forest is best seen in Fiordland National Park in the southernmost part of South Island, New Zealand. The park has an area of 12,519 square km. It is renowned for the rugged grandeur of its fjords, mountains, forests, waterfalls, and lakes. On the lower slopes of the mountains a rich cover of dense podocarp and beech rain forests is found.
Citations:
(1) South West New Zealand website.
(2) "Fiordland National Park," Britannica Online.
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