Nature-based solutions work with natural systems to address environmental challenges.

After severe flooding in 2019, Terrain NRM restored two erosion hotspots in the Mossman catchment—Bamboo Creek and the Mossman River—using nature-based solutions (NbS).

Five years on, these sites show how working with natural systems—not against them—can stabilise riverbanks, support vegetation, and improve resilience to future floods.

The two sites, one at Bamboo Creek (BC-1) and one on the Mossman River (MR-2), were restored using a combination of nature-based engineering techniques and revegetation. Thanks to funding from the Minderoo Foundation, we’ve been able to revisit these sites to see how they fared after major weather events, including during Tropical Cyclone Jasper (2023), and to understand how nature-based solutions perform under real-world conditions in the Wet Tropics.

Lessons learnt

1. Smart design starts with the right location
Nature-based solutions succeed when they match the natural behaviour of the river. At the Bamboo Creek site, revegetation has thrived because it was placed above the active channel, where it is only occasionally inundated. This reduced exposure to strong flows and erosion, allowing vegetation to establish and strengthen the bank.

2. Nature-based solutions can significantly reduce erosion
At the Mossman River site, timber pile fields reduced erosive forces dramatically – by up to 75–90% in smaller flows and by around 50–75% in larger flows. During Tropical Cyclone Jasper, the site experienced far less damage than was expected. Well-designed NbS can therefore meaningfully reduce the physical forces that drive erosion, and can protect both land and infrastructure.

3. After big change, smaller floods can cause bigger damage
One key finding from the report is that changes in site hydrology require adaptive design. Although the Mossman River site emerged from Tropical Cyclone Jasper with minimal impact, smaller flood events in 2026 caused significantly greater erosion and vegetation loss. The cumulative effects of the cyclone over the following three years fundamentally altered the Mossman River system, creating conditions that the original, site-specific nature-based design was not equipped to withstand.

4. Rivers change – designs must adapt too
Sediment deposited after Tropical Cyclone Jasper raised the riverbed at the Mossman River site by over one metre. This reduced channel capacity and increased flooding risk. This meant smaller floods began behaving more like larger events so NbS require adaptive management, rather than a “set and forget” approach to continue to protect the sites from the impacts of flooding.

WHAT IS IT?

The African Tulip Tree (Spathodea campanulata) is a fast-growing ornamental tree native to tropical Africa.

Easily recognised for its striking orange-red flowers, it was introduced to Australia as a garden plant but has become invasive in the Wet Tropics.

WHY IS IT A PROBLEM?

African tulip tree poses a significant threat to native ecosystems. It invades riparian zones, farmland, urban gardens and disturbed areas, outcompeting other vegetation and forming dense thickets.

Its dense canopy blocks sunlight, preventing the growth of understory plants and its flowers are toxic to native bees.

The tree produces large quantities of wind dispersed seeds, enabling rapid and long range spread. The tree suckers readily when disturbed or stressed, making it challenging to control.

CHARACTERISTICS 

It is an evergreen tree that grows to over 20 metres.

It has broad oval-shaped leaves with distinctive veins. The leaves are bronze-coloured when young, turning glossy green as they mature.

Flowers are a large orange to red with frilled yellow margins on the petals. The papery seeds are wind dispersed and form in elongated pods, up to 20cm long, which split lengthwise as they dry

HOW TO SPOT IT ON YOUR PROPERTY

Look for a tall tree with a wide canopy, glossy green leaves, and clusters of vibrant orange-red flowers. The presence of seedlings in nearby areas may indicate an infestation or mature tree nearby.

WHAT TO DO ABOUT IT 

• Prevention: Avoid planting African tulip and control/replace garden specimens with suitable non-invasive alternatives.
• Physical removal: Hand-pull freshly germinated seedlings.
• Chemical control: For established seedlings, saplings and mature trees, cut down and treat stumps with herbicide to prevent regrowth. Treat upper cut sections as well to prevent roots forming where it contacts the ground. No herbicide is currently registered for control of African tulip in Queensland. However, an off-label use permit (Permit No. PER11463 https://permits.apvma.gov.au/per11463.pdf ) allows use of various herbicides for control of environmental weeds in non-agricultural areas, bushland, forests, wetlands, and coastal and adjacent areas. Follow up control may be required.

Around the world, new environmental markets are emerging in response to an urgent challenge: how to rapidly accelerate investment into nature at the scale required to address climate change and biodiversity loss.

These markets take many forms—carbon, biodiversity, water and plastics—but share a common purpose. They provide credible frameworks to quantify and verify measurable environmental improvements, which can then be purchased, connecting private capital with on ground outcomes.

For investors, they represent an opportunity to support nature positive outcomes while responding to growing regulatory, reputational and market expectations.

Why are they being developed?

Most people are familiar with the climate crisis. Less widely recognised—but equally important—is the biodiversity crisis: the accelerating loss of plant and animal species and the degradation of ecosystems globally.

This is not just an environmental issue. Biodiversity loss threatens food security, human health, social stability and economic prosperity. More than 50 per cent of global GDP is considered moderately or highly dependent on nature.

These twin crises are interconnected and driven by human impacts on the natural world. Addressing them together is both possible and essential—but it requires coordinated action from governments, businesses, communities and landholders, supported by substantial investment.

Shifts in policy and significant increases in public environment funding are required to meet the scale and urgency of the challenge. However, financial input from the private and philanthropic sectors is also necessary to help bridge the significant funding gap. Environmental markets have emerged as one mechanism to help close this funding gap, by providing the framework to mobilise private capital into conservation, restoration and improved land management.

The global policy context

Momentum for nature positive investment has been strengthened by recent global policy developments.

At the United Nations Biodiversity Conference (COP15) in 2022, 195 countries and the European Union adopted the Kunming–Montreal Global Biodiversity Framework. A central commitment of the agreement is the protection of 30 per cent of the world’s land and water by 2030—the “30 by 30” target.

Delivering on these ambitious goals will require new financial mechanisms.

Environmental markets, including emerging biodiversity credit markets, provide a mechanism to channel private investment into nature protection and restoration at scale.

What’s happening in Australia?

Following the adoption of the Global Biodiversity Framework, Australia has moved to develop enabling policy settings and market infrastructure.

In 2024, the Australian Government released its Nature Positive Plan and announced the establishment of a national Nature Repair Market. The market is designed to enable private investment in projects that deliver verified, measurable improvements in biodiversity outcomes, creating new opportunities for investors to engage in nature positive action.

Alongside this national initiative, a range of state based and privately operated environmental markets continue to operate.

In Queensland, for example, the Reef Credit Scheme supports improvements in water quality flowing to the Great Barrier Reef. In New South Wales, Biodiversity Stewardship Agreements generate tradeable biodiversity credits under the Biodiversity Offsets Scheme. A growing number of voluntary programs also exist, catering to diverse environmental outcomes and investor preferences.

Within this evolving landscape, locally grounded, high integrity schemes play an important role in translating policy ambition into tangible outcomes on the ground.

In the Wet Tropics, lowland tropical rainforest grows in the high-rainfall coastal stretch between Cooktown and Ingham, mostly below 100 metres in elevation. It’s an ecosystem that thrives particularly well below 40 metres on rich alluvial and volcanic soils.

These forests are characterised by a diverse mix of tall, evergreen tree species, some rising above the main canopy. Large leaves, buttress roots, vines and palms give the rainforest its lush, layered structure.

A rich variety of wildlife depends on this habitat, including the southern cassowary, striped possum, tree frogs and the vibrant Ulysses butterfly.

In the Wet Tropics more than 70 per cent of the original lowland tropical rainforest has been cleared. Listed as endangered under national environmental law, it is an ecological community of high conservation priority—one that urgently needs protection and restoration.

This reinforced riverbank, just upstream from the Daintree River ferry crossing, was well underwater in the recent flooding rain – so we’re happy to report it has emerged unscathed to continue to do its job of stopping erosion.

One hundred metres of this riverbank was restored last year. Erosion problems had been worsening for years and Cyclone Jasper accelerated things in 2023, sweeping chunks of riverbank down the river and threatening the road running alongside the river.

Our solution, working with partners Neilly Group Engineering, was a combination of engineered rock work, earthworks and revegetation (mangroves, grasses and trees). And tree rootballs were embedded into the rock wall to better protect the mangrove plantings from flooding and to begin to replicate habitat conditions in established mangroves where large logs and branches collect and provide fish habitat.

The reinforced riverbank has now gone through multiple high rainfall events, with the latest nearing record high flows. Mangroves growing on the rockwall’s benching were the only part of the design that was significantly affected in the March flood. They will recover as tidal flows bring more mangrove seedlings from nearby vegetation.

Terrain NRM partnered with the Douglas Shire Council and Jabalbina Rangers for this project, which aims to stop an estimated 1,200 tonnes of fine sediment a year from washing down the river and out to the Great Barrier Reef lagoon

Terrain NRM’s Zack Severino says revegetation is the long-term solution, after a combination of rock and earthworks.

“We were dealing with a sheer drop. With every storm, more soil was getting washed away. Now we have a reinforced riverbank. And the upland area has been planted out with native, fast-growing trees to get a good root system embedded. Mangroves have been planted on the benched areas to catch sediment and more seedlings, so that’ll also help to secure the riverbank, and also filter the water.

The ‘Daintree Wetlands: Reef Coastal Restoration in the Lower Daintree’ project is being delivered by Terrain NRM through funding from the Australian Government’s Reef Trust through their Reef Coastal Restoration Program grant.

Neighbours on the upper Beatrice River near Millaa Millaa are banding together to revegetate riverbanks and restore critical wildlife habitat – doubling a landmark restoration effort in one of Queensland’s most ecologically significant landscapes.

When coral scientists Dr Mary Stafford-Smith and Dr Charlie Veron bought their riverside property, they saw more than grazing land. They saw a rare opportunity to restore a stretch of upland rainforest that scientists have identified as one of the region’s most important refuges against climate change.

Now, with support from Terrain NRM, the couple and their downstream neighbour Bruce Jenkins are joining forces to restore upland rainforest on their properties and reconnect critical wildlife corridors.

Veron family: ‘We have big plans for this land”

The Veron family – Dr Stafford-Smith and Dr Veron along with daughter Eviie and son Martin – own four adjoining blocks near the headwaters of the Beatrice River, with 1.5 km of river frontage and remnant upland rainforest. Their property is in a priority wildlife corridor linking Maalan National Park to Wooroonooran National Park and it’s also considered to be an important climate refugia – a potential haven for species as climate change impacts increase.

“We have big plans for this land,” Dr Stafford-Smith. “When Terrain NRM invited a range of scientists and practitioners along for an on-site planning day last year, it enabled us to start putting a plan of action together and make connections with people who can support us, including the Mamu Traditional Owners.”

Bruce Jenkins: Cattle and conservation

Their downstream neighbour Bruce Jenkins, a semi-retired pub owner from the Northern Territory, was also at the planning day. Mr Jenkins bought his 120-acre grazing property seven years ago and has been quietly transforming it ever since – fencing off the river and springs to exclude cattle, establishing a rainforest nursery and planting thousands of native trees beside the Beatrice River.

“I just love trees and the environment,” he said. “I want to leave this place better than I found it.”

Both properties are now being supported through Terrain NRM’s Forest Resilience project, which includes revegetation, weed control, conservation agreements and wildlife-friendly fencing along the river to exclude cattle.

Feral pigs (Sus scrofa) pose a serious threat to the delicate ecosystems and agricultural landscapes of the Wet Tropics.

Highly invasive and destructive, these animals uproot native vegetation, spread weeds, prey on wildlife, and damage crops—causing both environmental degradation and economic loss.

WHAT ARE FERAL PIGS?

Feral pigs (Sus scrofa) are highly destructive, invasive animals found across the Wet Tropics. They damage ecosystems by uprooting vegetation, spreading weeds, and preying on native wildlife. Their presence also threatens agriculture, causing crop losses and soil erosion.

WHY ARE THEY A THREAT?

• Environmental damage: Pigs disturb soil, degrade waterways, and destroy native habitats.
• Agricultural losses: They eat crops, damage fencing, and compete with livestock for food.
• Disease transmission: Pigs can spread diseases like leptospirosis and foot-and-mouth disease.
• Increased weed spread: Their movement spreads invasive plant seeds, worsening weed infestations.

HOW TO CONTROL THEM ON YOUR PROPERTY

The Cassowary Coast pig trapping guide provides a comprehensive overview of what is involved in a successful trapping program, but the key elements are:

• Installing smart traps: Set up remote-controlled enclosures in high-activity areas.
• Using pre-baiting: Encourage pigs to enter traps by providing food sources.
• Monitoring remotely: Use cameras and sensors to track pig activity before triggering the trap.
• Following ethical guidelines: Ensure humane handling and disposal of captured pigs.

WHAT ARE THEY?

High biomass grasses, like Gamba grass (Andropogon gayanus), Guinea grass (Megathyrsus maximus), grader grass (Themeda quadrivalvis), thatch grass (Hyparrhenia rufa) and giant rats tail grass (Sporobolus pyramidalis and Sporobolus natalensis), are introduced grass species that grow rapidly and produce large amounts of vegetation.

These grasses were often introduced accidentally or as pasture grasses for grazing but have become invasive after escaping from cultivation.

WHY ARE THEY A PROBLEM?

High biomass grasses outcompete native vegetation, reduce biodiversity, and alter fire regimes. Their high biomass creates huge fuel loads which generate intense fires that can destroy ecosystems, threaten wildlife, and damage property.

They also invade agricultural lands, reducing productivity and significantly increasing management costs. Many species are not palatable to stock so they can have a two way impact on pastures.

HOW TO SPOT THEM

Look for tall, dense grasses with distinctive seed heads and rapid growth. High biomass grasses can dominate disturbed areas, roadsides, and pastures. They may initially turn up in places where materials like soil have been imported from other areas, or where seed has fallen off vehicles, machinery, raw materials or animals.

Early detection is the key to prevent more seed being added to the system.

CHARACTERISTICS 

Gamba Grass 
A large perennial grass which grows up to 4m tall, forms dense tussocks, and has broad leaves with a white midrib.

Guinea Grass 
A large tufting perennial grass which reaches 3m in height, with long, narrow leaves and pyramid-shaped seed heads.

Grader Grass

An annual tufted grass up to 2m tall, with distinctive reddish-brown stems and fan shaped seed heads.

Thatch Grass 
A perennial grass up to 3m tall, with smooth leaves and tangled, thatchlike tufts and long stems with distinctive dark bands.

Rats Tail Grasses 
Rats tail grasses such as giant rats tail grass have distinctive cylindrical seed heads and tough, rasp like leaves which make them unpalatable to stock and other grazing animals.

A tiny frog with a big problem has sparked a mountain-top rescue mission in Far North Queensland.

Conservationists are working in dense rainforest near the summit of Mt Lewis, north of Cairns, to save the critically endangered mountain-top nursery-frog which is facing two challenges – feral pigs and a changing climate.

The frog is roughly the size of a thumbnail and it lays eggs under leaf litter. It is only found in high-altitude cloud forests in Mt Lewis National Park near Julatten.

Feral pigs a major threat

Terrain NRM’s Dr Andrew Dennis says feral pig numbers appear to be increasing above 1,100 metres, based on the amount of disturbance being seen.

“Over time they’ve slowly migrated upwards from the low altitude areas of the mountain,’’ he said.

“In mountain-top nursery frog breeding sites up near the top of Mt Lewis, pigs are now digging up the ground and leaving bare soil where there was leaf litter and tree seedlings, and we’ve observed them digging in the roots of the Linospadix apetiolatus palms.

“These tiny frogs breed in leaf litter. The males call from the palms, to project their voices to females. Eggs are laid in the leaf litter on the palm leaves or the ground. Where it’s deep, it also holds a lot of food for them. But with pig disturbances, they are losing both breeding and feeding zones.”

Installing pig-exclosure fencing

One of the answers is pig exclosure fencing. Terrain NRM has been working with Western Yalanji Traditional Owners and Gulf Savannah NRM to erect fences around 10 breeding sites in dense cloud forest near the top of the mountain. Now they’re also working with the Queensland Parks and Wildlife Service and James Cook University researchers, using frog-call monitors and regular habitat assessments to monitor these sites and rare frogs.

“Breeding season is generally from October-November to March,’’ Dr Dennis said.

“We have 10 fenced sites that exclude pigs and 10 control plots that aren’t fenced and they’re all about 60 metres apart so that calls from frogs at one plot shouldn’t be heard at another.

Audio recorders for population monitoring

“We have audio recorders at each site to monitor calling activity and we’re also regularly monitoring the habitat, measuring things like seedling and leaf litter density and any recovery of the Linospadix apetiolatus palms.

“Pigs are churning up significant areas of this fragile habitat. We are measuring this as part of the project. On a wider scale, they’re also a weed and water quality threat to a highly biodiverse area of the Wet Tropics at the headwaters of the Mitchell and Mossman River systems.”

Climate change a threat to frogs high up on Mt Lewis

At least five frog species have disappeared from the top of Mt Lewis in the past few decades, with three of them likely extinct worldwide. Dr Dennis said a fungal disease had been the main cause of their demise, but climate changes pose another threat to species at the high altitudes of ranges like Mt Lewis.

“I’ve been visiting this region for well over 50 years. Walking in the cloud forest and around the creeks, it used to be noisy with frog calls day and night. Now it’s noticeably a lot quieter.”

Frog’s trill tells a sad story

The mountain-top nursery frog’s trill is also diminishing.

“Calls were detected by researchers in 2003 at 1,100 metres. But 20 years later, in 2023, there were no calls at 1,100 metres. They were detected at 1,200 metres and above.

Beachside forests are feeling the love, with a blitz on invasive weeds and escaped garden plants and fruit trees at Mission Beach, Kurrimine Beach and Ingham’s Forrest Beach.

Littoral rainforest is critically endangered on the east coast of Australia and work is underway to better protect what is left in the Wet Tropics region.

Work crews target Forrest Beach

Work crews from Hinchinbrook Shire Council have been removing weeds including lantana, prickly pear and guinea grass from the largest patch of littoral rainforest in their region – an 80- hectare strip of council reserve between the ocean and wetlands just north of homes at Forrest Beach.

They are also removing garden plants, and cashew trees believed to have spread from an agricultural trial in the area back in the 1960s.

Removing cashew trees 

Biosecurity and Public Spaces Portfolio Councillor Kate Milton said cashew trees had been taking over some areas of forest.

“First our council crews spent time walking through the forest area mapping weed sites, then they treated areas,’’ Cr Milton said.

“There is a lot less now but seed banks are a problem. Our crews are doing follow-up work at the moment and that’s something we’ll keep doing once a year.”

Hinchinbrook Shire Council received funding from not-for-profit organisation Terrain NRM through a project centred on the Wet Tropics region’s littoral rainforest, lowland rainforest, Mabi forest and broad leaf tea-tree woodland – all of them threatened ecological communities. The project is also helping threatened species in wet sclerophyll forest and upland rainforest.

Preserving an endangered forest type

Terrain NRM’s Tony O’Malley said Forrest Beach’s littoral rainforest was in good condition considering its closeness to developed areas.

“The Forrest Beach community and Council are to be congratulated for preserving this outstanding patch of beachfront rainforest with its at least a century-old white apple trees.

“The best investment is keeping these kind of forests in the best possible condition so they are more resilient to threats like erosion, pest species and fire,’’ he said. “As well as its ecological value, including being home to wildlife, this reserve is an erosion buffer and a scenic area for the Forrest Beach community.”