Extensive efforts are being made to rid Samoa of a weed problem, invasive plants that threaten the nation’s biodiversity.

The urgency to eliminate invasive weeds such as the Rattan palm and the fake kava has never been greater, as these actions are vital to protecting native species and ecosystems.

Recent discussions held between the Samoa Ministry of Natural Resources and Environment (MNRE), and representatives from the Secretariat for the Pacific Regional Environment Programme (SPREP) and Pacific Regional Invasive Species Management Support Service (PRISMSS), led to a realisation of identified opportunities for collaboration.

Coordinated efforts between, MNRE and the PRISMSS Restoring Island Resilience War on Weeds (WOWs) and Resilient Ecosystems Resilient Communities (RERC) programmes, will commence to implement weed-led and site-led projects to support and enhance invasive species management in Samoa.

Under the PRISMSS WOWs programme activities, efforts will be focused on completely eradicating any remaining Rattan palm, a vine-like plant, with prickly spines making its handling and removal difficult, from the Tuaefu area.

The rattan palm is considered invasive in Samoa and is believed to be in low numbers currently following eradication efforts that began as far back as 2006, with its last remaining site at Tuaefu.

The species, which was introduced in the 1990s for a failed cane furniture business, and has since become a high-climbing, evergreen plant that can grow into dense clumps with many aerial stems.

The Acting ACEO for the Division of Environment and Conservation, MNRE, Vatapuia Maiava, expressed that, “safeguarding Samoa’s unique, yet fragile biodiversity through invasive species management is essential for maintaining ecosystem stability, culture, and Samoa's future.”

“We are grateful for the assistance provided by SPREP-PRISMSS because, through this collaboration, we are one step closer to protecting our natural resources and environment for the benefit of our present and future generations,” he said.

“This initiative reinforces our combined commitment to sustainability and resilience through the effective management of invasive species.”

Trial plantations for Rattan palm took place at three main locations across Upolu which included Vailima, Tuaefu and Togitogiga. Previous efforts by MNRE coordinated with various partners including the Samoa Conservation Society and Samoa National Invasives Task Team (SNITT), resulted in the complete removal of the Rattan palm from Vailima and Togitogiga.

The plant can cause habitat destruction by damaging other vegetation in the forest, leading to habitat loss for wildlife. It can also cause forest degradation by disrupting the natural regeneration of forests, potentially leading to further degradation. Rattan palm also makes walking in the forest a potentially painful exercise of negotiating around the sharp spines that snag on clothes or skin.

SPREP Invasive Species Adviser, Mr David Moverley, commented, “Removing Rattan palm from Samoa has been a concerted effort over many years for which Samoa should be proud and we are grateful that we can be of assistance in the last stages of this eradication effort and hopefully help to rid Samoa of this plant for good”.

Two restoration sites were also identified for Samoa following consultations with MNRE, which are the Mt. Vaea Nature Reserve at Vailima, and the Faleata Recreational Reserve at Tuanaimato, Faleata.

A site-led project under the PRISMSS RERC programme will target Mt. Vaea Nature Reserve with a focus primarily on the removal of the false kava (Piper auritum) from the Apaula stream that runs from the south to the northeastern side of the Reserve.

Their rapid growth and ability to outcompete native plants, particularly when introduced to ecosystems where it is not native, makes them one of the concerning invasive weeds in the region as the false kava can grow in dense native forests and can quickly displace other native plants and damage ecosystems. The plant is difficult to eradicate because it can continue to grow from any part of the plant.

The false kava is estimated to cover about 2ha of the reserve along the plains of the Apaula stream covering all the three management zones of the reserve, which are the Mt Vaea Nature Reserve, Robert Louis Stevenson’s Scenic Reserve, and the Vailima Botanical Garden which will provide reference points for the operation.

PRISMSS Programmatic Coordinator, Mr Josef Pisi shared that, “the initial control phase will involve removing the false kava from the stream and infested areas, which will lead to follow up operations to remove younger plants.

“We will closely engage with the Vailima community, youth group and welcome other nearby community members who would like to get involved, in hand pulling the false kava from the infested site, so they get a better understanding of why it’s important to manage invasive weeds and how to do it safely and properly”.

The second restoration site identified for the RERC activities will be implemented at the Faleata Recreation Reserve for the removal of Cordia Alliodora weed species.

Several tree planting programmes have been implemented in the Faleata Reserve over the past ten years where unwanted weeds were removed and replaced with native plant species but the Cordia Alliodora species has become prevalent at the site, which has caused problems to native species regeneration within the reserve following cyclone Evan in 2012.

“As the Cordia Alliodora multiplies much faster than it can be harvested it outcompetes indigenous vegetation to become a problematic invasive species which can lead to the displacement of native plant communities and alter ecosystem balance,” shared the PRISMSS Programmatic Coordinator.

The RERC programme, led by the SPREP invasive species team, integrates community involvement in ecological restoration, ensuring that resilient ecosystems provide direct benefits to local communities.

By managing invasive species and reintroducing native species, the programme activities intend to create sustainable environments where both nature and people can thrive together.

MNRE in their continued efforts has also most recently adopted the PRISMSS Natural Enemies-Natural Solutions (NENS) project which will explore the use of biological control agents to control invasive plants.