Erosion control

Script for planting for erosion control

[Opening drone shot of a slip. The words “Planting for erosion control” are superimposed over the shot.]

[Shows a white screen with the logo for the Ministry of Primary Industries and the logo for Te Uru Rākau – New Zealand Forest Service. At the bottom of the screen, the text says “Te Uru Rākau – New Zealand Forest Service is a business unit of the Ministry for Primary Industries.”]

[Shows a green screen with white text. The text says "What is erosion and why is it a problem?"]

Narrator is Louise Askin – Senior adviser, Hill Country Erosion Programme

Erosion is where water, wind or gravity remove soil and rock. Erosion is a natural process, but it’s exacerbated by human land use. There are many areas of New Zealand that are prone to erosion, particularly in our hill country.

Erosion is a problem for several reasons. It can make land less productive and sustaining through the loss of valuable soils. It can damage infrastructure such as fencing, roads, bridges, and even housing; and reduce water quality when large amounts of sediment enter rivers, streams, estuaries, and the coast – also harming aquatic ecosytems and mahinga kai.

If you’re a landowner, planting trees can help prevent erosion on your land.

[Shows a green screen with white text. The text says "What types of erosion are there?"]

Different regions and landscapes experience different types of erosion. The main broad types are:

• mass movement erosion, such as landslides, slips, earthflows, and slumps
• surface or run-off erosion
• stream bank erosion caused by water carving out the soil.

[Shows a green screen with white text. The text says "How can trees help?"]

You can plant trees within your farm to help stabilise erosion-prone land over time. Trees and their roots help protect land from erosion, especially during storms. They do this by providing forest cover that intercepts and soaks up rainfall; reducing the amount of water soaking into the soil – slowing down flood flows in rivers as a result; and providing a net of roots that binds the soil together.

There are many other benefits from planting your erosion-prone land. You can:

• make your farm more resilient when storms hit
• provide shade and shelter for livestock
• improve water quality by reducing sediment getting into waterways
• store carbon dioxide from the atmosphere
• restore native biodiversity
• create an additional source of farm income.

[Shows a green screen with white text. The text says "What types of trees should you plant?"]

There are different options available to reduce erosion by strategically planting trees on your farm. The right choice for you depends on your land type, its erosion risk, and what other outcomes you are after. Options for planting include the following:

Space planting – this is where you plant trees with wide spaces between them and graze livestock underneath. This method is useful if you want to stabilise grazing land, and it also provides shade and shelter for livestock. You can plant trees such as fast-growing poplars and willows, or eucalyptus or even some native species.

Native reversion – this is where you retire land from grazing or from production forestry and let it revert to native vegetation. If you have a seed source of native trees nearby, reversion might occur naturally if you manage the pest animals and weeds. Or you can actively bolster reversion by planting native trees.

Forestry – this is where you exclude livestock and plant a forest or small woodlot. Forests not only help stabilise land, but also provide an income if you harvest the trees, and potentially through the Emissions Trading Scheme. You can plant a range of exotic or native species. However, if you’re planting for harvest, then make sure that the land type is suitable and will not create a worse erosion risk at harvest.

Riparian planting – this is where you exclude lifestock and plant vegetation alongside waterways. This reduces streambank erosion and filters sediment and run-off before it enters the stream. You can plant a mix of native trees, grasses and shrubs depending on which part of the streambank you're working with.

[Shows a green screen with white text. The text says "Where can you get advice?"]

When it comes to planting for erosion control, it’s best to get some advice specific to your property and your region. 

Te Uru Rākau – New Zealand Forest Service supports erosion control programmes across the country through our Hill Country Erosion Programme. The Programme partners with regional councils who work directly with farmers in most regions. 

Ask your regional council land management officers for advice and if funding support is available. They can advise on what type of planting or land treatment will be most effective for your particular erosion issue. They can also work with you to draw up an erosion control plan for your farm if you like.

You can also talk to Te Uru Rākau – New Zealand Forest Service’s forestry advisers at the Ministry for Primary Industries. Contact them via our website or at forestserviceadvice@mpi.govt.nz

[Shows a white screen with email and website addresses. The email is forestservice@mpi.govt.nz and the website is mpi.govt.nz/forestry]

Protecting New Zealand’s erosion-prone land is a big job and well-designed planting on your farm all helps.

[Shows a white screen with the logo for the Ministry of Primary Industries and the logo for Te Uru Rākau – New Zealand Forest Service. At the bottom of the screen, the text says “Te Uru Rākau – New Zealand Forest Service is a business unit of the Ministry for Primary Industries.”]