Included here is New Zealand (North and South islands), Stewart Island and a multitude of smaller islands.

Neozeylandic Coastal Dune Formations (General)

Sand dunes have been described as New Zealand's most common landform and use to cover some 129,000 ha with some extending for up to 12 miles inland in some places. However, this has now been reduced to about 39 000 ha which equates to something like a 70% reduction. The main losses have been to afforestation. Other losses have been caused by agricultural development, sand mining, urbanisation, uncontrolled grazing, waste disposal and military activities.

The most extensive dunes are on the west coast of North Island, but large areas also occur on the east and north of South Island and on the west of Stewart Island. They can be broadly divided into mobile or semi-mobile dunes, fixed dune grassland, dune scrub and dune slack. In mobile dunes Spinifex hirsutus and the generic endemic Desmoschoenus spiralis (Cyperaceae) are the main sand-binding species, but near Foveaux Strait Festuca littoralis often becomes the primary sand builder. Where semi-stable conditions prevail the rare endemic Euphorbia glauca (Euphorbiaceae) may be encountered. In the case of fixed dune grasslands, very little remains in its primitive status and typically includes many exotic grasses and legumes. Indigenous species include Danthonia semiannularis, Microlaena stipoides and in northern districts Zoysia pungens. Dune scrub is usually distinguished by the endemic Coprosma acerosa (Rubiaceae) and Pimelea arenaria (Thymelaeaceae) although the latter is replaced by the endemic Pimelea lyallii in South Otago and Stewart Island. Dune slacks can be broadly divided into primary and secondary associations. The endemic Gunnera arenaria (Gunneraceae) is often the first arrival on damp sand forming circular patches up to 2 m in diametre. Other characteristic pioneer species include Carex pumila, Epilobium billardieranum, Scirpus cernuus and the endemic Epilobium nerteroides (Onagraceae) and Lilaeopsis novae-zelandica (Apiaceae), while in North Island and in the northern parts of South Island Limosella tenuifolia, Lobelia anceps and the endemic Myriophyllum votschii (Haloragaceae) become important.  In secondary association, shrubs usually dominate with Leptospermum scoparium often forming the main species. Other species on the northern shores of Cook Strait, for example, include Heleocharis cunninghamii and the endemic Potentilla anserinoides (Rosaceae).

North Island Dune Systems (Manawatu)

At the time of European settlement these dunes were probably fairly stable but grazing by cattle and possible burning caused destabilization and major sand movement. However, the re-establishment of Spinifex and the planting of introduced marram in the 1890s have done much to restore stablility. Four major vegetation types are recognised:

Foredunes
These are usually well developed ranging in height from 3 to 8 metres. Spinifex sericeus is usually the dominant species on seaward faces and in this situation forms a more effective sand binder than marram and has greater tolerance of salt spray. Introduced marram (Ammophila arenaria) can also occur on seaward foredunes and tends to create steeper, high foredunes than Spinifex. The native endemic sedge Desmoschoenus spiralis (Cyperaceae) is also common on foredunes but only flourishes where there is continuing supply of sand and soon succumbs during deflation. On the landward side of foredunes other species such as Cassinia leptophylla, Coprosma acerosa and Pimelea arenaria may be present. 

Dune Slacks (behind foredunes)
Slacks frequently form behind most foredunes. These are nearly all colonised by Carex pumila and Selliera radican.  In damp depressions further inland other pioneer species occur include Limosella lineata, Myriophyllum votschii and Ranunculus acaulis.

Sand Plains
Where water tables are about 30 cm deep Scirpus nodosus becomes one of the main species, but these areas also favour many exotic herbs such as Hypochaeris radicata, Lagurus ovatus, Leontodon taraxacoides, Melilotus indica and Medicago lupulina, while the introduced Lupinus arboreus is more abundant in the dryer areas.  In areas where the water table is closer to the surface Leptocarpus similis predominates together with Cortaderia toetoe, Epilobium billardieranum, Juncus holoschoenus and Schoenus nitens.

Rear Dunes
In the past before marram was introduced these areas did not mature to the same degree since there is no indigenous species ecologically equivalent to marram as a lee stabiliser. 

South Island Dune Systems (Chrystalls Beach)

The dunes here are of particular interest since they still support many native species and dune hollows still retain their largely native cushion plant communities.  Four major vegetation types have been recognised: foredunes, rear dunes, hollow-grass formations and cushion plant formations.

Foredunes
Much of this zone is dominated by the introduced Ammophila arenaria while the introduced Sonchus oleraceus represents the second most important species. In the past the endemic sand binding sedge Desmoschoenus spiralis (Cyperaceae) would have dominated this zone but now usually only occurs as a few scattered patches. It tends to disappear shortly after Ammophila becomes established. Other species found here include the introduced Anthoxanthum odoratum, Cirsium arvense, Cirsium vulgare, Dactylis glomerata, Holcus lanatus, Hypochaeris radicata, Leontodon taraxacoides, Lupinus arboreus Senecio elegans, Trifolium repens, the native Acaena novae-zelandiae, Calystegia soldanella, Isolepis nodosa, Pseudognaphalium luteoalbum, Pteridium esculentum, Senecio biserratus, Stokesiella praelongum, and the endemic Hydrocotyle heteromeria (Apiaceae) and Poa cita (Poaceae)

Hollow-Grassland
Occurring between the front and rear dunes this community is dominated by tall grasses but also includes occasional shrubs, smaller species and a few cushion plants. Unfortunatley much of the flora is made up of  exotic species including Agrostis capillaris, Agrostis stolonifera, Ammophila arenaria, Anthoxanthum odoratum, Cerastium fontanum, Cirsium arvense, Cirsium vulgare, Crepis capillaris, Dactylis glomerata, Holcus lanatus, Hypochaeris radicata, Leontodon taraxacoides, Lupinus arboreus, Rubus fruticosus, Rumex acetosella, Solanum dulcamara, Sonchus oleraceus, Stellaria media, Trifolium repens, Trifolium dubium and Ulex europaeus. Scattered native species include Dichelachne crinita, Isolepis nodosa, Muehlenbeckia australis, Muehlenbeckia axillaris, Pteridium esculentum, Senecio biserratus, Stokesiella praelongum and the endemic Cardamine debilis, Hydrocotyle heteromeria, Hydrocotyle novae-zelandiae var. montana, Phormium tenax, Poa cita and Poa maniototo. The vegetation has been divided into five subtypes all of which are dominated by alien invasive species:

Agrostis stolonifera and Rubus fruticosus dominated stands
These occur on flat land at moderate distances from the shore. Ulex europaeus is also common here.

Cerastium fontanum and Holcus lanatus dominated stands
These stands which frequently include Ammophila arenaria are typically found adjacent cushion plant comminities.

Anthoxanthum odoratum, Calystegia soldanella, Dactylis glomerata and Lupinus arboreus dominated stands.
These are found near the rear dunes.

Trifolium repens dominated stands
Found towards the rear of dune hollows these typically include the native grass Dichelachne crinita and the native orchid Microtis unifolia.

Cushion Plant Formations
These form in particular parts of dune hollows and represent the most species rich dune communities. In addition to cushion plants such as the endemic Raoulia australis (Asteraceae), others such as the endemic Geranium sessiliflorum (Geraniaceae) occur as isolated rosettes. Between these the areas are mostly covered by mosses (e.g. Campylopus introflexus and Tortula sp.) and/or patches of quartz pebbles. Other species in this zone include the native Acaena microphylla, Hydrocotyle novae-zeelandiae, Neopaxia australasica, Pernettya macrostigma, Selliera radicans and the endemic Colobanthus muelleri, Epilobium komarovianum, Luzula celata, Myosotis pygmaea var. pygmaea, Pimelea prostrata, Poa maniototo and Scleranthus uniflorus. Common exotic species include Leontodon taraxacoides, Rumex acetosella and Trifolium repens. Taller plants such as Isolepis nodosa mainly occur towards the edges of the cushion zone.

Rear Dunes
Forming a zone at the rear of the dunes the plants here are mainly dominated by the native Isolepis nodosa and the introduced Dactylis glomerata. Other common species include Agrostis capillaris, Pteridium esculentum and the endemic tussock grass Poa cita. Other species include the introduced Anthoxanthum odoratum, Bromus diandrus, Holcus lanatus, Hypochaeris radicata, Lupinus arboreus, Trifolium repens, Ulex europaeus and the native Calystegia soldanella, Dichelachne crinita and Muehlenbeckia australis.

References

Cockayne, L. 1958. The Vegetation of New Zealand. H. R. Engelmann (J. Cramer).

Drobner, U., Steel, J. B., Smith, B. & Wilson, J. B. 1995. The sand dune vegetation of Chrystalls Beach, southern New Zealand, with particular reference to the cushion community. New Zealand Journal of Ecology, 19: 143-151.

Esler, A. E. 1970. Manawatu Sand Dune Vegetation. Proceedings of the New Zealand Ecological Society, 17: 41-46.

Hilton, M., Macauley U. & Henderson, R. 2000. Inventory of New Zealand's active dunelands. Science for Conservation 157. Published by Department of Conservation, Wellington, New Zealand.

Molloy, L. 1994. Wild New Zealand. The MIT Press, Cambridge, Massachusetts.