Planting a mixed range of tree species has many environmental and conservation benefits. It can provide a habitat for birds and bees, protect against pests and environmental hazards, improve water quality and protect soil and land from erosion.
Biodiversity planting benefits
Trees are part of a wider ecosystem that define the habitat of a site. Planting a mixed range of trees can:
- provide shelter and food to a range of species like birds, animals, insects and fungi
- protect your trees from diseases
- provide flood protection and slope stability
- help our native tree species survive.
Our native species differ between regions, depending on the environment they grow in. If a species that grows in an area dies out, it may not be able to grow there in the future. That tree's regional biodiversity is then lost.
Trees provide environmental and conservation benefits such as:
- improving water and soil quality
- flood protection and erosion control
- species habitat for birds, bats, insects and lizards
- wildlife corridors
- flora and fauna species protection
- seed islands (provide a future seed source)
- protection of older growth forests and habitats.
If you have existing native bush you want to protect, you may be able to add a QE11 covenant to it. Check out the QE11 Trust website for more information.
Benefits that people get from the environment, including forests, are known as ecosystem services. Read more about some of the ecosystem services from forests.
Trees provide a carbon sink and the amount of carbon produced increases as they grow. You can claim carbon credits for tree planting if you meet certain conditions.
How to plant for biodiversity
Plan your site
Good planning is the key to success. You need to think about:
- What you want to achieve. For example, do you want to restore the original vegetation (including wetland areas)? Are you planting for a specific purpose like requirements under the national freshwater regulations or protecting a bird species?
- Is there any funding available to help you with your project?
- Where do you want to plant? Is there existing vegetation or seed source that could be protected and enhanced?
- Do you need to stage your project over multiple years? Will this make planting and later maintenance more manageable?
- What time and resources are available for planting and maintenance? For example, you need ongoing weed and pest control for at least 3 years until the plants are established.
Choose the right trees for your location
You can find out what grows well where you live by:
- contacting your local council and nurseries
- looking at what is growing in neighbouring areas. Some regional councils might have aerial images you can use to identify tree species
- identify the environmental factors that your plants will need to deal with. For example, soil type, terrain and climate conditions like annual rainfall, drought conditions and wind.
- talking to your neighbours.
Ecosource your native trees
Ecosourcing is when seedlings are grown from seed that is collected from mature trees in local native bush areas.
Using eco-sourced seedlings will ensure that your plantings have better survival and growth rates as they're suited to local conditions. Ask your seedling supplier where your seedlings were sourced from.
Plant a mix of species at different times
Aim to plant at least 6 to 7 different species to start.
Start with hardy, nursery species that establish well like flaxes, cabbage trees and manuka. Once they are established, you can plant your secondary species like matai and rimu. The existing seedlings from the first planting provide protection for the secondary, slower growing forest species.
Link in with other planting projects
Find out if there are other local planting projects that you can link in with:
- Talk to your local council to see if they are aware of any catchment groups in your area.
- Talk to your neighbours and see if you can link up planting areas.
- Are there any local planting programmes you can join with?
Trees for birds
Trees provide food, water, shelter and nesting sites for birds. They allow birds to spread out and can tie in wildlife corridors. Birds spread seeds and help with forest regeneration.
Planting different species gives birds many options to suit their preferences.
Forest & Bird has advice on which native plants attract native birds.
The Department of Conservation has information on what to plant and a calendar showing when plants provide food for birds.
Trees for bees
Both native and exotic trees provide an important food source for bees. You need to plant a range of species that flower at different times so there’s a food source all year round.
Trees for Bees have guides for planting for bees including regional planting guides and information on designing and planting for bees.
Trees for instream ecology like eels and native fish
Planting along waterways provides a buffer strip that can improve water quality and habitats, such as for eels and native fish. It also provides:
- shading along waterways to restrict aquatic plant and algae growth
- shading to lower water temperature to levels native fish can tolerate
- an important food source for aquatic animal life.
Tane’s Tree Trust has an article on planting for aquatic biodiversity.
Biodiversity Hawke’s Bay has information on local biodiversity and links to funding bodies.