New Zealand’s climate
New Zealand’s climate is warm enough for grass to grow all year, so farm animals can be grazed outside year-round. But animals and plants need shelter from New Zealand’s strong winds.
Shelter for gardens and farms
European settlers planted shelter belts – lines of trees to protect their farms, gardens and orchards against wind.
Why plant shelter belts?
Shelter belts slow down the wind, in order to:
- reduce loss of moisture from the soil
- make plants and animals less likely to get chilled
- stop plants being battered by wind
- make it easier for insects to pollinate plants.
Animals and shelter
Sheep, cattle, deer and farm dogs can rest in the shade in hot weather, and are protected from cold winds in winter. This helps them to stay healthy.
- In droughts, the foliage of some shelter-belt trees can be cut and fed to animals.
- Planting certain tree species encourages bees and other helpful insects, as well as birds.
Most farm shelter belts are planted with non-native trees – usually radiata pine or macrocarpa. Native trees like lemonwood (tarata) or ngaio can also be used.
Shelter belts around orchards are often alder, eucalyptus, poplar, willow or casuarina trees.
Shelter belts should allow some wind to go through. This works better than a solid wall.
They can be a single row of trees, or two or more rows.
To reduce wind, they should be across the direction of the prevailing wind. Planting them north–south stops them casting too much shade.
Problems with planted shelter
- Some trees used in shelter belts have fast-growing roots that invade nearby land.
- Tall trees may shade a crop, reducing its growth.
- Some tree species are poisonous to animals, and can make them miscarry their pregnancies.
- Pests such as possums sometimes live in the trees.
Other types of shelter
- Dairy shelters are large sheds where stock can be housed and fed. They are used in winter and spring to keep cows off the pasture for part of each day, and in summer to stop the animals getting too hot.
- Artificial shelter, made of tall posts and windbreak material, is sometimes built around horticultural crops.