What is a shrub?
A shrub is a small woody plant, usually with many stems that start close to the ground. New Zealand has about 445 native shrubs.
What are shrublands?
Shrublands are areas where shrubs are the tallest plants. They are found around New Zealand, from the coast to the high mountains.
- Some shrublands are temporary. They are one stage in the development of forests – larger trees will later grow up through them.
- Others are permanent. They grow in areas that are too harsh for trees.
Features of native shrubs
- Many native shrubs are dense, wiry and tangled, with small leaves.
- Nearly all are evergreen – they have leaves year-round.
- To stop them losing water, many have leaves that are very small, or waxy with hairs underneath.
Lowland and hill country shrublands
On the plains and hills, most shrublands are on land that used to be in forest. If the shrubs are not burnt or eaten by animals, these areas will develop into forest again.
- Mānuka shrublands can last for 30–70 years before forest grows there instead. Mānuka is the most common native shrub, and can grow on cleared land.
- Broadleaved shrublands are made up of fast-growing trees like wineberry, rangiora, māhoe and tree ferns.
- Gorse and Scotch broom were brought by European settlers for their gardens and hedges, and have spread into shrublands.
- Alpine shrublands are above the treeline (the upper limit of forests).
- Leatherwood scrub grows on the wet western mountains, and consists mainly of shrub daisies.
- Heather shrubland occurs in Tongariro National Park, where non-native heather was planted.
Dry country shrublands
In the dry eastern South Island and Central Otago, people burnt the forests. These areas are now mainly shrubland or grassland.
- Kānuka shrublands are usually a stage in regenerating forest. But in very dry areas, they can be permanent.
- Matagouri, the only native plant with thorns, forms shrublands among tussock grasslands.
- The sweet briar rose was planted by settlers, but has spread through much of the South Island.
Many plants from the heath family grow on very poor soils, including:
- gumlands, where kauri forests once grew
- peat bogs
- volcanic soils.
Value of shrublands
Shrublands provide important habitats for insects, fungi, birds and lizards. They stop hills from eroding, and also help forests regenerate.