Family: Fabaceae

Acacia saligna (Port Jackson wattle, golden wreath wattle) is a fast-growing, perennial shrub or small tree native to southwestern Australia. It typically reaches heights of 3–8 meters and is known for its bright yellow, fragrant flower clusters and long, narrow, blue-green leaves. Widely planted for ornamental purposes, erosion control, and as a nitrogen-fixing species, A. saligna adapts well to poor soils, coastal conditions, and dry environments. Its rapid growth and ability to thrive in disturbed areas make it popular in restoration projects, but also contribute to its potential invasiveness.

In many regions outside its native range, A. saligna has become naturalized and is considered a potentially invasive species. It can form dense thickets that outcompete native vegetation, alter soil chemistry through nitrogen fixation, and reduce habitat availability for native plants and animals. Its prolific seed production and tolerance of a wide range of environmental conditions allow it to spread quickly, particularly in disturbed areas. Management often involves preventing seed dispersal, mechanical removal, and targeted herbicide application to control its spread.

High Risk Traits:

• Highly invasive in Mediterranean climates (e.g., South Africa, Israel, California).
  
• Forms dense thickets, displacing native vegetation and reducing biodiversity.
  
• Prolific seed producer (up to 10,500 seeds per m² annually).
  
• Long-lived seed bank (seeds remain viable for decades, germinating after fire or disturbance).
  
• Nitrogen-fixing, altering soil chemistry and promoting weed invasions.
  
• Rapid growth & early reproduction (matures in <5 years).
  
• Resprouts after cutting or fire, making eradication difficult.
  
• Spread by birds, ants, water, and human activity (e.g., road construction).
  
• Seeds survive digestion, aiding long-distance spread.
  
• Tolerates poor soils, drought, and salinity, enabling colonization of harsh environments.

Low Risk Traits:

• Not toxic to humans or livestock; used as fodder in dry regions.
  
• No spines/thorns, reducing physical harm.
  
• Limited shade tolerance, restricting spread in dense forests.
  
• Controlled by herbicides (e.g., glyphosate, triclopyr) when properly applied.
  
• Prefers disturbed sites; less invasive in intact ecosystems.