Invasive pasture grasses in northern Australia - gamba grass, para grass, olive hymenachne, perennial mission grass and annual mission grass - Introduction

THREAT ABATEMENT ADVICE FOR A KEY THREATENING PROCESS

About this advice

In 2009 a key threatening process (KTP) was listed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act): ‘Ecosystem degradation, habitat loss and species decline due to invasion of northern Australia by introduced gamba grass (Andropogon gayanus), para grass (Urochloa mutica), olive hymenachne (Hymenachne amplexicaulis), mission grass (Cenchrus polystachios syn. Pennisetum polystachion) and annual mission grass (Cenchrus pedicellatus syn. Pennisetum pedicellatum)’. A threat abatement plan was prepared for this key threatening process in 2012.

This threat abatement advice was prepared by the Department in consultation with key stakeholders to provide guidance at national, state and local levels on activities and research needed to abate the threat.

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Invasive pasture grasses in northern Australia – gamba grass, para grass, olive hymenachne, perennial mission grass and annual mission grass (PDF - 558.36 KB)

Introduction

In 2009 a key threatening process (KTP) was listed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act): ‘Ecosystem degradation, habitat loss and species decline due to invasion of northern Australia by introduced gamba grass (Andropogon gayanus), para grass (Urochloa mutica), olive hymenachne (Hymenachne amplexicaulis), mission grass (Cenchrus polystachios syn. Pennisetum polystachion) and annual mission grass (Cenchrus pedicellatus syn. Pennisetum pedicellatum)’. Gamba and the two mission grasses are weeds of terrestrial habitats while para grass and olive hymenachne have invaded wetlands. All five species are weeds of northern Australia.

These five invasive pasture grasses were imported into northern Australia between the 1880s and the 1980s. Unfortunately, without careful management they can easily escape from pastoral areas into bushland or wetlands and affect the structure and function of environmental assets, including threatened species and ecological communities. By increasing fuel loads, they are capable of causing intense fires which endanger human and animal lives and destroy native vegetation. They can also alter nutrient and water availability for native plants. As a result, invasion of these grasses has lead to ecosystem degradation, habitat loss and biodiversity decline.

The Threat abatement plan to reduce the impacts on northern Australia’s biodiversity by the five listed grasses was released in 2012 as a guiding document designed to minimise the adverse impacts of these five grasses on affected native species and ecological communities. Having a threat abatement plan encourages all relevant government agencies, landholders, industry and community groups to work together to prevent further damage to our environment.

As an extension to the plan, these web pages aim to bring together information to help prevent further damage by these invasive grasses. There are links to documents which provide ideas for practical on-ground abatement activities for local communities, natural resource management groups, landholders or other interested individuals. Also available are broader actions for government agencies, local councils, research organisations, industry bodies or non-government organisations that have been identified as important to minimising the impacts of these five grasses.

Status of the five invasive grasses under state and territory legislation

Gamba grass (Andropogon gayanus) is listed as a Weed of National Significance and a declared weed under Western Australian, Northern Territory and Queensland legislation.

Para grass (Urochloa mutica) is not a declared weed under any legislation in any jurisdiction.

Olive hymenachne (Hymenachne amplexicaulis) is a Weed of National Significance and a declared weed under legislation in all Australian jurisdictions.

Perennial mission grass (Cenchrus polystachios syn. Pennisetum polystachion) is a declared weed under Northern Territory and Western Australian legislation.

Annual mission grass (Cenchrus pedicellatus syn. Pennisetum pedicellatum) is not a declared weed under any legislation in any jurisdiction.

Status of the five invasive grasses under Commonwealth legislation

‘Ecosystem degradation, habitat loss and species decline due to invasion of northern Australia by introduced gamba grass (Andropogon gayanus), para grass (Urochloa mutica), olive hymenachne (Hymenachne amplexicaulis), mission grass (Pennisetum polystachion) and annual mission grass (Pennisetum pedicellatum)’ is listed as a key threatening process (KTP) under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). This KTP meets the criteria stated in section 188(4)(a) and section 188(4)(c) of the EPBC Act and is eligible to be listed as a KTP because:

• it could cause the native species Cycas armstrongii (a cycad) to become eligible for listing as vulnerable under the EPBC Act
• it could adversely affect at least four species that are listed as endangered under the EPBC Act, primarily through altered local fire regimes, degradation of habitat and reduction of food sources. The examples presented in the KTP listing advice are: Lucasium occultum (Diplodactylus occultus, yellow-snouted gecko), Erythrura gouldiae (Gouldian finch), Euploea alcathoe enastri (Gove crow butterfly) and Epthianura crocea tunneyi (yellow chat – Alligator Rivers).

The Threat abatement plan to reduce the impacts on northern Australia’s biodiversity by the five listed grasses was developed in 2012 to address this KTP. This plan provides guidance to minimise the adverse impacts of the five listed grasses on affected native species and ecological communities. The Australian Government environment minister must review the plan before December 2017.

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