From planting trees along creeks to trapping feral pigs – neighbours are joining forces in the Wet Tropics so that new land conservation projects can deliver more ‘bang for the buck’.

A strong response from private landholders has meant 14 projects will start soon between the Daintree, Tablelands and Ingham on land in important areas between forests – where tree-planting and pest and weed control can make a big difference.

Seven of the projects cross property boundaries.

Connecting endangered Mabi forest

“Cane farmers along a creek near Atherton are planting trees in what could be the beginnings of a new green corridor connecting sections of endangered Mabi forest between the Curtain Fig National Park and Wongabel State Forest,’’ Terrain NRM’s Bronwyn Robertson said.

Removing pond apple

“Further south, pond apple is being removed across 50 hectares near Babinda thanks to an agreement with neighbouring landholders. This builds on previous work in the area to control pond apple and improve habitat condition.

Feral pig control

“At Topaz and in the Daintree, feral pig control programs will bring neighbouring landholders together over more than 200 hectares of high-value habitat.”

These new projects are part of ‘Green Connections’, funded by the Queensland Government’s Natural Resource Management Expansion Program. Community conservation groups and local councils will be working on many of them.

Tree planting to help mahogany gliders

Ms Robertson said the program was targeting areas where conservation investment could deliver the greatest benefits. It also includes tree-planting along a creek in the Ingham area to help endangered mahogany gliders, and the expansion of a Tableland couple’s forest restoration project at the base of Mt Bartle Frere, Queensland’s highest mountain.

WHAT IS REVEGETATION?

Revegetation is planting native vegetation to restore ecosystems and suppress invasive weeds. It is a proactive approach to weed management, promoting biodiversity and stabilising disturbed landscapes.

WHY IS IT USEFUL? 

Without revegetation, disturbed areas are vulnerable to weed invasion, which can outcompete native plants, disrupt ecosystems, and increase fire risks. Weeds thrive in degraded environments, making revegetation a very useful strategy for long-term weed control.

CHARACTERISTICS 

Revegetation focuses on selecting native species suited to local conditions. These plants establish quickly, creating cover and shade that suppress weed growth. Revegetation also improves soil health, water retention, and habitat connectivity.

HOW TO APPLY IT ON YOUR PROPERTY

Revegetation for weed control is useful in areas subject to constant weed establishment and growth. Look for areas with sparse canopy, erosion issues, weed thickets or exposed soil. These are prime candidates for revegetation efforts. With a little effort and careful planning, native plants could be thriving in revegetated areas, while weeds are minimised.

HOW TO GET STARTED

• Project planning and costing: It is important to have a plan upfront and understand the duration, costs and materials required for your revegetation project. You may have to order plants well in advance to take advantage of the best planting conditions. Maintenance requirements can be very site specific so it’s best to consult with local experts at community and council revegetation nurseries to understand your local conditions.
• Site preparation: Control and remove existing weeds and prepare the soil for planting. This may take several rounds of weed control to reduce the seedbank of grasses and weeds.
• Species selection: Choose native plants adapted to local conditions and resistant to weed competition. Talk to your local revegetation nursery or contractor.
• Planting: Use a mix of species and growth forms to create a diverse ecosystem.
• Maintenance: Monitor growth, remove weeds, and ensure plants are healthy.

The hunt is on for the invasive weed stevia in the Ravenshoe and Herberton region.

Stevia ovata, or candyleaf, is in flowering season so now (June) is the best time to identify it.

Terrain NRM is working with Tablelands Regional Council on a project to control this weed and to keep it from spreading any further in Australia than the Atherton Tablelands, the only place it has been found.

Flowering season – May-June – easiest time to identify stevia

Terrain’s Evizel Seymour said stevia, which has the potential to compromise grazing land and natural vegetation, is controllable if everyone works together.

“Research has shown the seed only lives for 18 months and is not as mobile as something like Siam weed,’’ she said. “It was first found in this region in 2007. The growing season is February to May with a flowering season from the end of May through June.

A controllable weed if everyone works together

“We know this is one of the weeds we can get on top of. The best time to control stevia is before it flowers but identifying it is the first step to controlling it.”

Terrain NRM secured funding through the Queensland Government’s Queensland Feral Pest Initiative to follow on from earlier stevia control work by partnering with Tablelands Regional Council to work with landholders and others including Ergon Energy, Powerlink, Clean Co and the Queensland Parks and Wildlife Service.

Control work, with herbicides, is reducing the size of outbreaks on private and public land.

“Getting to stevia before it flowers and sets seeds means there is no seed bank for the future,’’ Evizel said. “By July to August the top of the plant dies off naturally but the bottom can re-shoot with moisture and the problem continues unless it is being controlled.”

Thousands of fish barriers – from weirs to causeways and culverts – are affecting native fish populations in the Wet Tropics and impacting commercial and recreational fishing.

A recent study in the Daintree, Mossman and Barron River estuaries identified more than 1600 potential barriers for fish, and earlier studies of the Herbert and Murray River estuaries identified more than 3000.

Terrain NRM’s Lana Hepburn said results have led to work at 18 sites in the Herbert and Murray catchments to modify causeways, retrofit fish passageways and control weeds, but a lot more work needs to be done.

The natural resource management organisation is calling for more funding to improve fish populations across the Far North.

“More than half of Australia’s fish species, including barramundi and jungle perch, spawn in estuaries and need to move upstream to breed and complete their life cycles,” Ms Hepburn said.

“As small fingerlings, it’s impossible to get past road crossings and weirs, dams, drop-offs and fast-flowing water. Even weeds and a lack of light can impact fish migration.”

Ms Hepburn said fish barriers were identified through geospatial mapping and aerial photography, before field trips to do the ‘ground truthing’.

So far, about 200 of the 1600 sites identified in northern waterways have been visited by a team from Terrain NRM, Wet Tropics Waterways, Catchment Solutions and the Dawul Wuru Aboriginal Corporation’s Yirrganydji Land and Sea Rangers.

“About 60 per cent of the sites we’ve visited have significant barriers to fish migration,’’ she said. “The goal is to open up as much upstream habitat as we can.’’

Terrain NRM is prioritising barriers for fixing, based on the best return on investment. At this stage, there is no fish barrier funding for the Daintree, Mossman and Barron catchments beyond the barrier identification project.

“Our priorities are usually the sites closest to an estuary and on larger waterways with more riparian areas,’’ Ms Hepburn said. “The closer a barrier is to the coast, the more upstream habitat it is blocking. The distance between each barrier is important too.

The ongoing battle with weeds in the Wet Tropics region has led to a three-year project across 40 hectares of land that has trialled different methods on the edges of world heritage rainforest.

Terrain NRM has worked with the Cassowary Coast, Douglas and Tablelands regional councils on projects that are buffering world heritage forest from fire and weeds, and restoring woodland habitat. They have also involved revegetation work.

Project coordinator Chelsy Maloney said the goal was to improve the resilience of big patches of native vegetation by managing emerging threats in smaller patches of neighbouring vegetation.

Restoring fire-damaged rainforest near Silkwood

In the Cassowary Coast region, the focus was a fire-damaged section of rainforest on a council reserve along the edges of world heritage rainforest.

“With the likelihood of more rainforest fires given our changing climate, it’s important to learn how to best restore these areas,’’ Terrain project coordinator Chelsy Maloney said.

“Cassowary Coast Regional Council worked with us on a weed management and revegetation project where we trialled low-cost assisted regeneration to support rainforest restoration. We found that by managing the high threat weeds, more space and less competition was created for natural recruitment and pioneer species. In the short term, the forest condition showed a definite improvement.”

Weeds were managed on 3.5 hectares of world heritage rainforest and a strip of revegetated land along the roadside.

Revegetating woodland understorey near Ravenshoe

In the Tablelands region, an infestation of guinea grass and lantana in council reserve land beside South Cedar Creek at Ravenshoe was the focus.

“In woodlands the canopy can often be intact while the understorey is overtaken by weeds. By managing lantana and guinea grass, we’ve started to see lots of different understory species recruiting across 10 hectares, and an increase in native species overall.

“We also trialled high-density understorey revegetation work on 1.5 hectares in an attempt to out-compete exotic pasture grasses such as guinea grass, and there have so far been really good results.”

Can a small fish make its way up the rivers and tributaries in the Lower Barron, Mossman and Daintree catchments? That’s the basis for a project that’s assessing if infrastructure like weirs, dams and culverts are stopping fish moving upstream to nursery and breeding grounds.

These river catchments are hotspots for diadromous fish species like barramundi and jungle perch – adults spawn in estuaries and juvenile fish migrate upstream to freshwater habitat where they mature into adults.

More than 1600 potential barriers have been identified as part of a new project aiming to improve recreational fishing outcomes by improving waterway habitat connection.

Terrain NRM’s Lana Hepburn explains that a number of factors determine which barriers would be most beneficial to remediate to get good recreational fishing and ecological outcomes.

“The goal is to open as much habitat upstream as we can, so we look at where the barrier is in the catchment. If it’s closer to the coast it’s potentially blocking more upstream habitat – so the distance between each barrier is important too.

“We also look at how connected a waterway is to the ocean. Barriers in rivers that connect to the ocean would be prioritised over small tributaries that flow into different creeks and rivers before hitting the ocean,” Lana said.

Some barriers are only obvious in low flow conditions during winter, but fish need to be able to migrate at different times of the year.

A field team from Terrain NRM, Wet Tropics Waterways and Dawul Wuru Aboriginal Corporation’s Yirrganydji Land & Sea Rangers have now physically inspected hundreds of barriers to assess their priority for remediation.

Known for its distinctive shrieks, rattles and gurgles, the endangered Yellow-bellied glider (Wet Tropics) is getting a helping hand with some extra habitat upkeep.

Tall eucalypt forest in a narrow strip on the western edge of the World Heritage Area is home to the glider but the habitat is threatened by alteration and fragmentation. There are only three known remaining local tableland populations of the Wet Tropics sub-species of gliders left.

Terrain NRM’s Dr Andrew Dennis said the Gilbey Forest, on state forest and adjacent private land near Herberton on the Atherton Tablelands, is the habitat for one of the populations but weed infestations are putting the habitat at risk. Lantana camara, a transformer weed of national significance, is a particular concern in the area as it can drastically change ecosystem condition and function.

“Yellow-bellied gliders live in ‘dens’ in large rose gums in tall eucalypt forest and their survival depends on what remains of that habitat being in top notch condition. The right mix of species must be able to grow and recruit new den and feed trees, but lantana forms dense thickets that can stop young trees from growing and prevents critical forest regeneration,” he said.

Now, a one-off weed control program funded by the Queensland Government’s Natural Resources Investment Program and delivered by Terrain NRM, will control an area of significant lantana infestation.

The program builds on existing, longstanding work by the Yellow-Bellied Glider Project volunteers of the Tree Kangaroo and Mammal Group. The group has been looking after parts of the Gilbey Forest for decades and monitoring resident gliders. They have partnered with landholders, traditional owners, scientists, schools and other community groups to care for and manage the area.

Yellow-bellied gliders rely on two main habitat trees. They live in the hollow limbs of soaring rose gums where small family groups live in “dens”, and they tap the trunk of the red mahogany for its clear, sugary sap.

Dr John Winter, part of the team caring for the glider, has been involved with the fluffy gliders since the seventies.

“Back then nobody much bothered with the wet sclerophyll forests – they were actually completely overlooked for years and years. These days they are far more prominent in people’s minds as an important ecotonal habitat.”

Pond apple, a major environmental weed, has been surveyed and removed from 115 hectares of land in the Murray catchment near Tully, in an effort to improve wetland habitat.

Introduced to Australia as grafting stock for commercially grown custard apple, pond apple has become a serious weed in Queensland. It is listed as a weed of national significance.

Aquatic weed management is part of Terrain NRM’s Fish Home & Highways project, which is improving fish habitat connectivity in the nationally significant wetland and coastal ecosystems of the Murray and Lower Herbert catchments.

Terrain NRM’s Deb Bass said the pond apple removal work builds on previous control efforts by Cassowary Coast Regional Council and Girringun Aboriginal Corporation in 2008 and 2015.

“Thanks to that work we had a good idea of areas to prioritise, and work was focussed along Warrami Creek. We’ll do a follow-up of the 115 ha next year to make sure everything has been caught, and we’ll then expand to take in more of the area previously surveyed.”

Local business NQ Forestry was contracted to undertake the on-ground control efforts.

The pond apple being targeted was along a creek line, so applying herbicide via stem injection is recommended. This minimised herbicide runoff and off-target impacts. However, each original stem maintains its own sap stream which complicates control – every single stem has to be cut and injected, not just the main stem.

“Pond apple control is labour intensive work, but this method is very effective and if we are consistent with control work we have a good chance of local eradication,” said Ms Bass.

An easy change to an agricultural weed control technique is helping farmers manage weeds, improve riparian vegetation and prevent streambank erosion.

Vegetation along waterways (known as riparian vegetation) is important for stabilising creek banks—tree roots hold the banks together and slow the water flow down, preventing erosion.

In recent times, landholders in the Mossman area have expressed concern about thinning or receding riparian vegetation. Given that creek bank erosion is a major issue for farmers it’s understandable they’re worried by the changes to their riparian zones.

Terrain NRM’s Ruginia Duffy said that planting trees is time consuming and can be expensive.

“The good news is we’ve learned that making a small tweak to traditional spraying regimes— switching from a non-selective to selective herbicide—is an easy and effective way of improving riparian condition,” said Ms Duffy.

Favourable climatic conditions in the Wet Tropics means the natural seed bank in the soil usually grow easily and unassisted.

However, when non-selective herbicides are used to control problematic weeds like guinea grass, native tree seedlings are also inadvertently sprayed out. Over time this hinders the riparian forest’s ability to regenerate and repair itself, leading to thinning and receding, and eventually bank erosion.

Marcus Bulstrode from the Queensland Department of Agriculture and Fisheries works with cane growers to support the development and uptake of sustainable farming practices.

A major threat to world-heritage rainforest in the Mossman area is sending work crews into the thick of forests.

Crews spent six weeks freeing-up a creek system on a property bordering Mossman National Park in the latest assault on the invasive weed hiptage which is smothering rainforest north of Cairns.

Douglas Shire Council Biosecurity Team Leader Brad Everett said the hiptage incursion was almost impenetrable.

“It’s a really hard, woody vine that grows up trees and smothers them – it gets so heavy it can bring the trees down,’’ he said. “Then it throws roots down and becomes a dense bramble.”

He estimates work crews cut down thousands of mature vines and removed tens of thousands of seedlings during the six-week campaign which is part of a regionwide Native Vegetation Improvement Project funded by Terrain NRM through the Queensland Government’s Natural Resources Investment Program.

“We almost had a monoculture – now the native forest can regenerate and self-seed in this area,’’ Mr Everett said.

Douglas Shire Council and the Queensland Parks and Wildlife Service have been working for more than a decade to contain hiptage in a 60-hectare section of the Mossman River Catchment.

“Over the years we’ve got to the stage where we can walk through sections that were once choked with hiptage and just remove one or two seedlings,’’ Mr Everett said.

“We run aerial surveys and on-ground monitoring each year. The funding from Terrain NRM will also allow us to begin another eradication program in coming months in a different Tara Hills area.”

Terrain NRM’s Tony O’Malley said work was also underway to improve the resilience of big patches of native vegetation on the Tablelands and in the Cassowary Coast region.

“This project has brought councils from across the region together to decide on priority areas of native vegetation where they can make measurable improvements over the next few years through funded on-ground works,” he said.