Acacia longifolia (Andr.) Willd.

Title: Acacia longifolia (Andr.) Willd.

Scientific Name: Acacia longifolia (Andr.) Willd.

Common Name: sallow wattle

Source & more images (via ALA)

Habitat: A. longifolia grows in partial shade to full sun and will tolerate a wide range of soil types, exposed positions and seasonal dry spells and occurs generally in areas receiving more than 550mm annual rainfall and has been recorded to elevations up to 150m in the USA (Calflora 2007; Muyt 2001). The species is an invader of heathlands, woodlands, forests, riparian habitats, grassland, coastal dunes and scrub (Muyt 2001; Weber 2003), as well as sclerophyll communities, coastal heath and scrub, river systems and catchments (Dennill, et al. 1993; Harden 2002).

Distribution:

Original source via CABI

Invasiveness Assessment

ESTABLISHMENT

1. Germination requirements? Disturbance around infestations usually stimulates mass germination of A. longifolia seeds. Stimulated to germinate by fire (Pieterse and Cairns, 1986). Although extensive growth occurs in areas where fire has not occurred for many years (Cavanagh and Tran, 1980). About 10% of fresh seeds germinate each year without any disturbance (Muyt, 2001).

2. Establishment requirements? Grows in partial shade to full sun and will tolerate a wide range of soil types, exposed positions and seasonal dry spells and occurs generally in areas receiving more than 550mm annual rainfall. (Muyt, 2001). Their ability to fix nitrogen has enabled them to invade nutrient-poor environments (Marchante et al, 2004). Can establish under moderate canopy cover.

3. How much disturbance is required? Occurs within heathlands, woodlands and forests (Muyt, 2001), also occurring riparian habitats, grassland, coastal dunes and scrub (Weber, 2003), sclerophyll communities and coastal heath and scrub (Harden, 2002).

GROWTH / COMPETITIVE

4. Life form? Upright spreading bushy shrubs to small trees; 1-8m (Costermans, 1983), which may produce dense thickets (Weber, 2003).

5. Allelopathic properties? Described as not having any allelopathic properties (PIER, 2007).

6. Tolerates herb pressure? Unknown: No information was found to document that A. longifolia can or cannot tolerate herbivory pressure and produce propagules.

7. Normal growth rate? A. longifolia is described as a rapidly growing shrub (Marchante et al, 2004), may equal competitive species of the same life form.

8. Stress tolerance to frost, drought, w/logg, sal. etc? Tolerates seasonal dry spells (Muyt, 2001) and described as being drought resistant (Garden California, 1997). Disturbance by fire stimulates mass germinate causing extensive growth (Pieterse and Cairns, 1986). Tolerant to drought and fire no information suggests tolerance to frost, water logging or salinity although maybe tolerant.

REPRODUCTION

9. Reproductive system? Sexual reproduction occurs (Muyt, 2001), self and cross pollination.

10. Number of propagules produced? A. longifolia produces huge amounts of seeds annually as many as 11,500 seeds have been recorded (Pieterse, 1987). Number of propagules produced per flowering event therefore maybe greater than 2000.

11. Propagule longevity? Long lived seeds are regarded as being paramount for the invasiveness of the plant (Pieterse, 1986 in Dennill and Donnelly, 1991). Seeds may remain dormant for well over a decade (Muyt, 2001).

12. Reproductive period? While A. longifolia may survive for over 50 years in its natural range, those in other areas commonly die within 25 years (Muyt, 2001). Pieterse and Cairns (1988) describe A. longifolia forming dense monocultures.

13. Time to reproductive maturity? Plants reach sexual maturity within two to three years (Muyt, 2001).

DISPERSAL

14. Number of mechanisms? Seed is dispersed by birds, ants, slashing, in soil and garden refuse (Muyt, 2001). Also noted by PIER (2007) that propagules are dispersed by water.

15. How far do they disperse? Due to seeds being able to disperse by birds (Muyt, 2001) and water (PIER, 2007), it can be concluded that propagules will disperse greater than one kilometre.

Impact Assessment

RECREATION

1. Restrict human access? A. longifolia produces dense thickets to 8m (Weber, 2003) which may impede individual access and cause difficulty for vehicle access.

2. Reduce tourism? A. longifolia is an upright spreading bushy shrubs to small trees; 1-8m, which may produce dense thickets. Also produces bright yellow flowers to 5cm in length (Weber, 2003). May cause minor effect to aesthetics.

3. Injurious to people? Reported by PIER (2007), as not being toxic to humans and not to cause allergies. No other reviewed documentation suggests the plant is injurious to people.

4. Damage to cultural sites? No reviewed documentation suggests the plant causes damage to indigenous, European heritage sites or infrastructure. Little or negligible effect on aesthetics or structure of site.

ABIOTIC

5. Impact flow? Unknown: No reviewed documentation suggests that A. longifolia impacts upon water flows within watercourses or waterbodies.

6. Impact water quality? Unknown: No reviewed documentation suggests that A. longifolia impacts on water quality.

7. Increase soil erosion? A. longifolia was introduced into South Africa as a dune binder and stabiliser to reduce erosion (Hagemann and Rose, 1988; Pieterse and Cairns, 1988). May decrease the probability of soil erosion.

8. Reduce biomass? Dense stands will shade out many ground-flora species, crowd out shrubs and severely impede overstorey regeneration (Muyt, 2001). The plant produces large amounts of litter increasing nitrogen and phosphorus content in the soil (Weber, 2003). This may mean A. longifolia directly replaces biomass.

9. Change fire regime? Dense stands of A. longifolia can burn at high intensities (Pieterse and Cairns, 1988). Mass germination of seeds occurs when stimulated fire, so fire increased frequency would benefit the species (Pieterse and Cairns, 1986). A. longifolia may cause moderate change to the intensity of fire risk.

COMMUNITY HABITAT

10(a) Impact on composition of high value EVC? EVC= Coastal Headland Scrub (V); CMA= Corangamite; Bioreg= Otway Plain; CLIMATE potential=VH. Where invasive, dense thickets may reduce native plant species richness (Weber 2003). A. longifolia encroaches into coastal interiors replacing indigenous flora and valuable natural grassland (Hagemann and Rose 1988). Dense stands will shade out many ground-flora species, crowd out shrubs and severely impede overstorey regeneration (Muyt, 2001). A. longifolia is described as forming dense monocultures (Pieterse and Cairns, 1988).

10(b) Impact on medium value EVC? EVC= Coastal Dune Scrub/Coastal Dune Grassland Mosaic (D); CMA= Corangamite; Bioreg= Otway Plain; CLIMATE potential=VH. Where invasive, dense thickets may reduce native plant species richness (Weber 2003). A. longifolia encroaches into coastal interiors replacing indigenous flora and valuable natural grassland (Hagemann and Rose, 1988). Dense stands will shade out many ground-flora species, crowd out shrubs and severely impede overstorey regeneration (Muyt 2001). A. longifolia is described as forming dense monocultures (Pieterse and Cairns, 1988).

10(c) Impact on low value EVC? EVC= Dunefield Heathland (LC); CMA= Mallee; Bioreg= Lowan Mallee; CLIMATE potential=VH. Where invasive, dense thickets may reduce native plant species richness (Weber, 2003). A. longifolia encroaches into coastal interiors replacing indigenous flora and valuable natural grassland (Hagemann and Rose, 1988). Dense stands will shade out many ground-flora species, crowd out shrubs and severely impede overstorey regeneration (Muyt, 2001). A. longifolia is described as forming dense monocultures (Pieterse and Cairns, 1988).

11. Impact on structure? Dense stands will shade out many ground-flora species, crowd out shrubs and severely impede overstorey regeneration (Muyt, 2001). A. longifolia has encroached into the coastal interior replacing indigenous flora and valuable natural grassland (Hagemann and Rose, 1988). Plant communities in dunes, naturally characterised by open structure and low cover can be transformed into Acacia woodlands, with arboreal structure, higher cover and low species number, decreasing species richness (Marchante et al, 2003). Pieterse and Cairns (1988) describe A. longifolia forming dense monocultures.

12. Effect on threatened flora? Dense thickets may reduce native plant species richness (Weber, 2003). A. longifolia may replace indigenous flora and valuable natural grassland (Hagemann and Rose, 1988). A Portuguese study found A. longifolia prevents the germination of therophytes and hemicryptophytes (Marchante et al, 2003). Although no specific information is documented on the effect of A. longifolia on VROT species.

FAUNA

13. Effect on threatened fauna? No specific information was found to document the effect of A. longifolia on threatened fauna species.

14. Effect on non-threatened fauna? Where A. longifolia is invasive, dense thickets may reduce native invertebrate species richness (Weber, 2003), reducing habitat and displacing individuals but not causing local extinction.

15. Benefits fauna? May provide as a food source for native invertebrates (Muyt, 2001). Although no other specific information is documented on the benefits of A. longifolia for indigenous fauna.

16. Injurious to fauna? Everist (1981) recorded stock poisoning by A. longifolia believing the toxic substance to be cyanides in the leaves. Although, no specific information was found to document that A. longifolia is injurious to indigenous fauna species.

PEST ANIMAL

17. Food source to pests? No specific information was found to document that A. longifolia provides a food source to assist in success of pest animals.

18. Provides harbor? No specific information was found to document that A. longifolia provides as important habitat or harbour for serious pests. Although A. longifolia produces dense thickets to 8m (Weber, 2003) which may provide harbor for serious pest species.

AGRICULTURE

19. Impact yield? Everist (1981) recorded stock poisoning by A. longifolia believing the toxic substance to be cyanides in the leaves.

20. Impact quality? Not described as a weed of agriculture. No literature suggests that A. longifolia impacts on the quality of agriculture.

21. Affect land values? Not described as a weed of agriculture. No literature suggests that A. longifolia affects land value.

22. Change land use? Not described as a weed of agriculture. No literature suggests that A. longifolia causes a change in priority of land use.

23. Increase harvest costs? Not described as a weed of agriculture. No literature suggests that the presence A. longifolia increases the cost of production.

24. Disease host/vector? A fungal disease of A. longifolia has been documented in South Africa. The disease starts as a leaf spot on small seedlings and proceeds to a lethal infection. The cause of the disease of A. longifolia was noted as Clindrocladium scoparium which is known as a widespread pathogen (Hagemann and Rose, 1988) in agricultural systems including conifer and hardwood seedling (Forest Pests, 2006). A. longifolia may provide host to a minor disease of agriculture.

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Assessment ratings originally made by the Victorian Department of Primary Industries.

The entry of this assessment was made possible through the generous support of The Weed's Network.

Attachments:

Acacia longifolia_ pot.doc
Acacia longifolia_pres.doc
1215503.jpg
distribution_map (3).png

referenced by (1)

wra1033: Common Name - S (via sallow wattle)

Article: wra2433 (permalink)
Categories: :wra:a, :wra:inv1, :wra:invmh, :wra:inv2, :wra:inv3, :wra:invh, :wra:inv4, :wra:invl, :wra:inv5, :wra:inv6, :wra:invm, :wra:inv7, :wra:inv8, :wra:inv9, :wra:invml, :wra:inv10, :wra:inv11, :wra:inv12, :wra:inv13, :wra:inv14, :wra:inv15, :wra:imp1, :wra:impmh, :wra:imp2, :wra:impml, :wra:imp3, :wra:impl, :wra:imp4, :wra:imp5, :wra:impm, :wra:imp6, :wra:imp7, :wra:imp8, :wra:imp9, :wra:imp10a, :wra:imph, :wra:imp10b, :wra:imp10c, :wra:imp11, :wra:imp12, :wra:imp13, :wra:imp14, :wra:imp15, :wra:imp16, :wra:imp17, :wra:imp18, :wra:imp19, :wra:imp20, :wra:imp21, :wra:imp22, :wra:imp23, :wra:imp24
Date: 23 October 2009; 1:12:48 PM AEDT

Author Name: Rebecca Grant
Author ID: rgrant