Taxonomy

Acacia saligna | Golden wreath wattle | Acáise shailduilleach

Distribution

Status

Legal status

Regulated Invasive Alien Species  of Union concern under the European Regulation on the prevention and management of the introduction and spread of invasive alien species [1143/2014].

Native status

Non-native

First reported in the wild

Not present in Ireland or Northern Ireland

Invasiveness

Not assessed

Irish status

Absent

NAPRA Ireland risk assessed

No

Species Biology

Identification

This evergreen species can be identified by its dense, wide base which often makes the plant look wider than it is tall (CABI, 2019). It is typically 2-6 m in length but can reach 9-10 m in areas where it has been introduced (CABI, 2019). The bark is grey (Branquart, Lozano and Brundu, 2018). The phyllodes (modified leaf steams that look like and function like leaves) are a dull green colour with a pronounced midrib, long and narrow to lanceolate in shape and 7-25 cm long (Branquart, Lozano and Brundu, 2018; CABI, 2019). The phyllodes are often suspended from the plant in a pendulous manner (CABI, 2019). A coarsely wrinkled, circular gland of 1-2 mm in diameter can be seen on the upper reaches of the phyllodes (Branquart, Lozano and Brundu, 2018; CABI, 2019). This species gives rise to spheroid racemes (unbranched inflorescence bearing flowers that have short floral stalks) consisting of 2-10 heads that are 5-10 mm in diameter and produce multiple bright yellow flowers (Branquart, Lozano and Brundu, 2018; CABI, 2019). The pods are thin and flat and are 8-12 cm long with a width of 4-6 mm (Branquart, Lozano and Brundu, 2018; CABI, 2019). Seeds are 5-6 mm long, 3-3.5 mm wide and are produced in large numbers (Branquart, Lozano and Brundu, 2018; CABI, 2019).

Ecology

In its native range of Western Australia, this evergreen species is widespread and can be found in habitats that provide adequate soil depth such as temperate woodlands, coastal scrublands, heathlands and riparian habitats (Branquart, Lozano and Brundu, 2018). Its natural range provides a Mediterranean climate with a mean annual temperature range of 11-23 ºC and an average of 580 mm of precipitation (Branquart, Lozano and Brundu, 2018). 
Due to its versatility, this species possesses the ability to become established in various semi-natural habitats across the globe (Branquart, Lozano and Brundu, 2018; CABI, 2019). It has been reported as established in riparian habitats, scrubland, forest, dune systems and grasslands (Branquart, Lozano and Brundu, 2018). Although it can establish itself in habitats that are generally more arid than its native range, this species is less competitive in habitats of this description (Branquart, Lozano and Brundu, 2018).

Habitat

Found in temperate woodlands, coastal scrublands, heathlands, riparian habitats and dune systems (Branquart, Lozano and Brundu, 2018; CABI, 2019). Optimal growth conditions will include deep sandy loams close to watercourses (CABI, 2019).

Mechanism of impact

Competition, Other

Management approach

Prevention of intentional introduction
As Golden wreath wattle is listed as an Invasive Alien Species of Union concern under the EU Regulations of Invasive Alien Species, it cannot be imported, traded, or released to the wild. Measures must also be taken to prevent spread of existing populations of it (European Commission, 2017). 
Control can be achieved through specific chemical control techniques such as drill-fill, cut-stump, frilling, stem-scrape and ring barking (Reynolds, 2017).

Chemical control
The cut-stump method has been implemented in the British Sovereign Bases in Cyprus (SBA) to tackle the spread of A. saligna (Reynolds, 2017). The cut-stump control method involves cutting down the trunks of the target plant before applying a herbicide (Reynolds, 2017). This method is effective with an 80-95% mortality rate after first application which can increase to almost 100% if follow up control is implemented (Reynolds, 2017).
The drill-fill management method involves the drilling of 45 degree holes into the plants cambium layer and immediately filling the newly drilled hole with a herbicide (Government of South Australia, 2019). Holes are drilled and subsequently filled every 2.5-5 cm until a ring of holes can be seen all the way around the base of the plant (Government of South Australia, 2019). Follow-up control is necessary to ensure the seeds littering the ground do not germinate and establish new populations of the unwanted species.
Frilling is the management practice of using a mallet or chisel to ‘frill’ the outer layers of the trunk, exposing the cambium and instantly applying herbicide to these exposed areas. The cuts should make a circle around the trunk and should be cut every 5 cm (Government of South Australia, 2019).
Stem scraping involves the scraping of a layer of bark (15-30 cm section) from the stem which is then immediately treated with a herbicide (NSW Department of Primary Industries, 2021). The exposed tissue will be more susceptible to the herbicide than the protective bark.

Mechanical control
Ring barking or girdling is a mechanical control method that involves cutting off a strip of bark (all the way around the trunk) in such a manner that it prevents the plant from being able to continue growing, resulting in its death (USDA Forest Service, 1999). 

Broad environment

Terrestrial

Species group

Plant

Native region

Australasia

Distribution

World distribution(GBIF)

Irish distribution

Absent

Native distribution

Native to South Western Australia.

Temporal change

Records submitted to Data Centre in 2024

The following map is interactive. If you would prefer to view it full screen then click here.

How can you help

Report any sightings of this species to the National Biodiversity Data Centre, including a photograph, if possible.

Dispose of unwanted specimens in a responsible manner that does not allow them in to the natural environment.

Avoid purchasing this species for ornamental purposes.

Further information

Branquart, E., Lozano, V. and Brundu, G., 2018. Risk Assessment: Acacia saligna. [online] Available at: <https://circabc.europa.eu/faces/jsp/extension/wai/navigation/container.jsp?FormPrincipal:_idcl=FormPrincipal:_id1&FormPrincipal_SUBMIT=1&id=7d683ffb-62ff-4e7b-bb1b-4fc3bcf8c52b&javax.faces.ViewState=6F3%2B%2B3sjbjGFWpk%2BcXxLjduSZPTcX5x9%2FvHuUGOcG0Yb879h> [Accessed 23 Jun. 2021].

CABI Invasive Species Compendium: https://www.cabi.org/isc/datasheet/2402

References

Publications

Branquart, E., Lozano, V. and Brundu, G., 2018. Risk Assessment: Acacia saligna. [online] Available at: <https://circabc.europa.eu/faces/jsp/extension/wai/navigation/container.jsp?FormPrincipal:_idcl=FormPrincipal:_id1&FormPrincipal_SUBMIT=1&id=7d683ffb-62ff-4e7b-bb1b-4fc3bcf8c52b&javax.faces.ViewState=6F3%2B%2B3sjbjGFWpk%2BcXxLjduSZPTcX5x9%2FvHuUGOcG0Yb879h> [Accessed 23 Jun. 2021].

CABI, 2019. Acacia saligna (Port Jackson wattle). [online] Available at: <https://www.cabi.org/isc/datasheet/2402> [Accessed 23 Jun. 2021].

European Commission, 2017. Invasive Alien Species of Union concern. [online] Luxembourg. Available at: <https://ec.europa.eu/environment/nature/pdf/IAS_brochure_species.pdf> [Accessed 25 Jun. 2021].

Government of South Australia, 2019. Weed management techniques. [online] Available at: <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiN5ujo2q3xAhVDQUEAHclnB2kQFjASegQIDhAD&url=https%3A%2F%2Fwww.naturalresources.sa.gov.au%2Ffiles%2Fsharedassets%2Fadelaide_and_mt_lofty_ranges%2Fplants_and_animals%2Fpests%2Fweed-man> [Accessed 23 Jun. 2021].

NSW Department of Primary Industries, 2021. Control techniques using herbicides. [online] Available at: <https://www.dpi.nsw.gov.au/biosecurity/weeds/weed-control/herbicides/control-techniques-using-herbicides> [Accessed 23 Jun. 2021].

Reynolds, D., 2017. Acacia Management on the British Sovereign Bases Cyprus. [online] Available at: <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjHmt3i163xAhWzmFwKHUZCBBAQFjAAegQIBhAD&url=https%253A%252F%252Fassets.publishing.service.gov.uk%252Fgovernment%252Fuploads%252Fsystem%252Fuploads%252Fattachment_data%252Ffile%252F660061%25> [Accessed 23 Jun. 2021].

USDA Forest Service, 1999. Tree Girdling Tools Tree Girdling Tools Part 1 of 3. [online] Available at: <https://www.fs.fed.us/eng/pubs/pdfpubs/pdf99242809/pdf99242809pt01.pdf> [Accessed 23 Jun. 2021].

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