Riparian Weed Control Program

Riparian Weed Control Program

 

One of the most extensive vine weed management projects undertaken in South East Queensland.

 

Mark WaudManaging invasive weed species to preserve water quality and improve the condition of riverbanks.

Up to 148km of creek bank have been cleared of the destructive environmental weeds, Cats Claw Creeper and Madeira vine.

Where physical removal of the weeds has not been possible, biological control agents have been released into infestation to help stem the growth and spread of invasive vine weeds. The biological control agents are approved for release within Australia and sourced from community groups.

Farmers community groups and local governments councils are working together to help improve the condition of the region’s riverbanks and reduce the input of sediment into local water resources.

 

The project focuses on:

  • Managing invasive weed species to preserve water quality in water catchments that provide cities and towns with drinking water.
  • Improving the condition of the region’s riverbanks to protect biodiversity and provide habitat.
  • Preventing sediment from entering Moreton Bay.
     

This project is an important part of Healthy Land & Water’s broader efforts towards a concerted war on weeds across South East Queensland, which has been actively rolling out on-ground works for more than 20 years.

 

Managing invasive weed species to preserve water quality, improve the condition of the region’s riverbanks to protect biodiversity, and provide habitat.

 

What we are doing

Cat clawsCats Claw creeper invading native vegetation

The program manages invasive weed species like Cat’s Claw Creeper, Madeira vine, and Chinese elm in targeted locations across the region that have been identified by Seqwater as critical to maintaining water quality.

The process involves:

  • Primary weed control. This involves physically cutting the vines off the vegetation, both at ground level and chest height. The stumps at ground level are scraped and painted with herbicide to kill the underground tubers. The cut vines between the ground and chest height are removed to allow visibility of new vines climbing trees.
  • Maintenance weed control. Vines from resprouting tubers and newly germinated seeds are sprayed with herbicide to prevent reinfestation. This has to be undertaken 4-6 times per year to prevent the vines from reaching the tree canopy. After approximately 5 years of control, the supply tubers is typically exhausted and maintenance requirements become less onerous. Ongoing monitoring and maintenance will likely always be required to prevent reinfestation from seed sources.
  • Where manual control is not possible due to lack of access, cost, or weed extent biological control agents are released.
  • For Cats Claw Creeper the agent of choice is Jewel Beetle, native to South America and raised in purpose-built facilities run by community groups. The beetle attacks the weed in two ways. Adult beetles feed on the growth tips of the plant and the larvae feast on the internal structure of the leaf once they emerge from the egg. This insect activity given time, weakens the plant, reducing seed set and allowing other pathogens to take hold and reduce the weed’s vigour.

Measuring success

We measure success with the length of riparian area under active management for cats claw. As the scale of the project increases, the logistics of scheduling regular maintenance rotations to prevent reinfestation by cats claw become increasingly complex. There are 148 kilometres of riparian area under management in 2023/24, which we aim to steadily increase this every year.

Over 100,000 jewel beetles have been released through the program at multiple locations throughout South East Queensland. While biological control agents will never destroy the host plant entirely, their presence reduces the impact of the weed, giving the native vegetation a chance to recover.

Control of these weeds protects existing native riparian vegetation, which provides the ecological service of long-term, sustainable delivery of clean water.

Why this project is important

The presence of foreign weeds is rapidly destroying South East Queensland’s precious ecosystems.

These invasive weeds continue to thrive in our environment due to the lack of natural predators and their ability to outcompete native flora for resources such as space, nutrients, and water.

Infestations of invasive vine species along riverbanks and in rainforests have devastating effects on our region as they can overgrow and kill mature canopy trees. This loss of vegetation results in streambank erosion causing dirty water quality, reduced fish stocks, and loss of vital habitats that support our unique fauna, bird, and reptile species.

 

Project snapshot

Project name: Riparian Weed Control Program
Project manager: Leonard Ainsworth, Healthy Land & Water
Catchment: South East Queensland
Timing: 2016 - current
Budget: $6 million over five years
Partnerships: This weed control program is made possible through funding from Seqwater and co-investment from Moreton Bay Regional Council who share the objective of preventing sediment from entering Moreton Bay and to preserve water quality in water catchments that provide supply drinking water.
Related Articles:

 

What's next

Healthy Land and Water signed a new 5 year agreement in 2023/24 to continue this successful work. There is huge potential to build on this through collaboration with land managers and other stakeholders to coordinate delivery and coinvest to expand the area of waterways where these invasive weeds are being controlled.

Project collaborators

This weed control program is made possible through funding from Seqwater and co-investment from Moreton Bay Regional Council who share the objective of preventing sediment from entering Moreton Bay and to preserve water quality in water catchments that provide supply drinking water.