Why Native Planting Is One Of The Best Ways To Control Erosion On Old Forestry Blocks In New Zealand
- Nadia Crighton
- Jul 1
- 5 min read
Quick Answer: Why Are Native Plants Good For Erosion Control?
Native plants help stabilise vulnerable New Zealand landscapes by protecting exposed soil, slowing water movement, supporting biodiversity and creating long-term root systems that bind the land together. On old forestry blocks, native restoration can be especially powerful because decomposing forestry slash, retained organic matter and sheltered conditions can provide an ideal foundation for native seedlings to establish.
Restoring Old Forestry Blocks With Native Plants
Across New Zealand, many old forestry blocks are being reconsidered not just as harvested land, but as landscapes with enormous restoration potential.
For Native Restorations, this work is about more than planting trees. It is about rebuilding ecosystems, protecting vulnerable soils and helping land recover in a way that supports long-term resilience.
To date, Native Restorations has helped establish approximately 40,000 native plants across restoration, erosion control, revegetation and habitat enhancement projects throughout the Marlborough and Kaikōura regions.
From vulnerable hillsides and former forestry blocks to wetlands, waterways and coastal environments, each project has been carefully designed to restore natural ecosystems, improve biodiversity and create long-term resilience within the landscape.
These projects demonstrate what can be achieved when the right native species are planted in the right location and supported through ongoing management and maintenance. The result is healthier land, stronger ecosystems and a lasting legacy for future generations.
Why Erosion Control Matters So Much In New Zealand
New Zealand’s landscapes are highly vulnerable to erosion. Steep hill country, intense rainfall, young geology, cleared native forest and land-use change can all contribute to soil loss.
When erosion occurs, it does not just affect the land where the slip happens. Sediment can move into streams, rivers, wetlands, estuaries and coastal areas, impacting water quality, aquatic habitats and downstream communities.
Research* has revealed that many regions in New Zealand are vulnerable to erosion, with topsoil loss degrading agricultural productivity and contributing sediment to waterways, estuaries and marine ecosystems.
This is particularly important on steep or exposed land where forestry has recently been harvested. Once canopy cover is removed, soils can become more exposed to rainfall, wind and surface water movement.
Why Old Forestry Blocks Need Careful Restoration
Old forestry blocks can present both risk and opportunity. After harvest, some sites may be left with exposed soil, compacted tracks, steep faces, slash, stumps, debris and altered drainage patterns. If these areas are not managed carefully, heavy rain can mobilise sediment and woody material.
The Ministry for Primary Industries has recognised the risk of forestry slash movement, noting that forestry slash from harvesting can sometimes be moved off-site by small landslides. New slash management requirements for higher-risk land are designed to help identify and reduce this risk.
However, not all post-harvest material is bad. In the right place, and when managed properly, decomposing forestry slash and woody debris can help protect soil, retain moisture and create sheltered microsites where native plants can establish.
Why Decomposing Forestry Slash Can Help Native Regeneration
On old forestry blocks, decomposing organic matter can provide an important starting point for native restoration.
As slash, branches, bark and leaf litter break down, they can:
· Add organic matter back into the soil
· Help retain moisture
· Provide shelter for young native seedlings
· Reduce direct exposure to sun and wind
· Support fungi, insects and soil biology
· Slow surface water movement
· Create natural seedling establishment zones
In some cases, harvested pine blocks can support natural regeneration where seed sources are nearby and browsing pests are controlled. Research prepared for Hawke’s Bay Regional Council has explored the transition from exotic pine forest to indigenous forest through natural regeneration, highlighting growing interest in best-practice approaches for converting former pine blocks into native forest.
This is where skilled restoration planning matters. Slash needs to be assessed carefully. Material that could move during storms or block waterways should be managed appropriately, while stable organic material may help support native establishment.
Why Native Plants Are A Smart Long-Term Choice
Native plants are not just beautiful. They are built for New Zealand conditions.
When planted and managed well, native species can help create resilient ecosystems that support:
· Soil stability
· Water quality
· Biodiversity
· Birdlife and insects
· Shade and shelter
· Long-term carbon storage
· Natural regeneration
Hawke’s Bay Regional Council has noted that using indigenous plants for erosion control can enhance conservation values and provide habitat, while also stabilising eroding areas.
Source:
Native vegetation can also help reconnect fragmented habitats. This is especially important in regions where native bush has been cleared or reduced over generations.
Native Planting And Erosion Control: What The Research Says
Research from Manaaki Whenua Landcare Research has explored the use of New Zealand native plants for erosion and sediment control, including their role in riparian planting, revegetation and slope stabilisation.
Source:
The Ministry for Primary Industries also published a 2024 review of current research into native forest establishment on extremely eroded land, showing the increasing national interest in using native forest restoration as part of erosion-prone land management.
While every site is different, the message is clear: erosion control is not just about stopping soil from moving today. It is about building living systems that become stronger over time.
The Best Native Plants For Erosion Control
The best native species depend on the site, soil type, slope, rainfall, exposure and restoration goals.
Common native species used in erosion control and revegetation projects may include:
· Mānuka
· Kānuka
· Harakeke
· Toetoe
· Tī kōuka / cabbage tree
· Karamū
· Kōhūhū
· Māpou
· Koromiko
· Carex and native grasses
· Tōtara in suitable sites
Fast-establishing native shrubs can help create early shelter, while longer-lived canopy species can be introduced as the site becomes more protected. The goal is not simply to plant trees. The goal is to create a layered native ecosystem that can protect soil, support wildlife and regenerate naturally.
Why Pest Plant And Animal Control Matters
Native planting on old forestry blocks is most successful when pest pressure is reduced.
Without control, pest plants can smother young natives, while browsing animals such as deer, goats, rabbits and possums can damage seedlings before they establish.
Restoration often requires:
· Pest plant removal
· Animal pest control
· Weed releasing
· Follow-up maintenance
· Monitoring plant survival
· Replanting where needed
This is why professional restoration is long-term work. Planting day is only the beginning.
A Practical Approach To Restoring Old Forestry Blocks
For Native Restorations, successful restoration starts with understanding the land.
A strong restoration plan may include:
· Assessing erosion risk
· Identifying waterways and sediment pathways
· Managing unstable slash
· Retaining useful organic matter where appropriate
· Selecting native species suited to the site
· Protecting seedlings from pests
· Monitoring survival rates
· Supporting natural regeneration over time
Old forestry blocks can become thriving native ecosystems, but they need the right planning and care.
Why Native Restoration Is An Investment In The Future
Erosion control is not just an environmental issue. It is a land protection issue, a water quality issue and a community resilience issue. By restoring old forestry blocks with native plants, landowners can help reduce sediment loss, improve biodiversity, protect waterways and support healthier ecosystems for future generations. Native restoration is not a quick fix. It is a long-term solution. But when done properly, it gives the land back its ability to hold itself together.
Work With Native Restorations
Native Restorations works with landowners, councils, community groups and organisations to restore vulnerable landscapes across Marlborough, Tasman, Kaikōura and surrounding regions. From pest plant control and revegetation to erosion management and native planting, the team brings practical, on-the-ground experience to complex restoration sites.
If you are managing an old forestry block, erosion-prone land or a site ready for native regeneration, Native Restorations can help create a practical plan for long-term recovery.
Sources:
Comments