Genista monspessulana (L.) L. Johnson

Title: Genista monspessulana (L.) L. Johnson

Scientific name:

Genista monspessulana (L.) L. Johnson

Common name(s):

Cape broom, Montpellier broom

Source & more images (via ALA)

Habitat: Subhumid and humid areas with a Mediterranean climate (Parsons and Cuthbertson 1992). It is an invasive weed of forest margins, neglected areas, roadsides and watercourses which occasionally encroaches onto poorer pastures in areas receiving more than 500 mm annual rainfall (Parsons and Cuthbertson 1992). Cape broom invades dry coastal vegetation, heathland and heathy woodland, lowland grassland and grassy woodland, dry sclerophyll forest and woodland, damp sclerophyll forest, riparian vegetation and rock outcrop vegetation (Carr et al. 1992).

Distribution:

Original source via CABI

Invasiveness Assessment

ESTABLISHMENT

1. Germination requirements? Seeds germinate in both autumn and spring. (Parsons and Cuthbertson, 1992 p.107)

2. Establishment requirements? Establishes as an understorey shrub in woodland and forest areas where it would receive shading from overstorey Eucalypts. (Carr et al., 1992)

3. How much disturbance is required? Establishes in minor disturbed natural ecosystems and healthy natural ecosystems e.g. heathland. National Parks (e.g. Dandenong Ranges National Park). (Carr et al., 1992; Gillespie, 1991)

GROWTH / COMPETITIVE

4. Life form? Erect, evergreen, leguminous shrub. (Parsons and Cuthbertson, 1992)

5. Allelopathic properties? None described.

6. Tolerates herb pressure? “Mature plants are unpalatable”. (Dept. of Primary Industries (Tas), 1990)

7. Normal growth rate? Forms dense thickets, which exclude most other vegetation. May completely smother surrounding vegetation. (Dept. of Primary Industries (Tas), 1990)

8. Stress tolerance to frost, drought, w/logg, sal. etc? Drought and frost tolerant. Occurs in freshwater wetland (seasonal). (Carr et al., 1992; Parsons and Cuthbertson, 1992)

REPRODUCTION

9. Reproductive system? Reproducing by seed. (Parsons and Cuthbertson, 1992)

10. Number of propagules produced? “Prolific seed producer”. > 2,000 flowers per bush (see pic. P & C 1992) therefore > 2,000 seeds per plant. (Parsons and Cuthbertson, 1992)

11. Propagule longevity? “Seed is long lived within the soil”. (IFFA 1989).
20-30 years. (McDougall, 1994)

12. Reproductive period? Forms dense thickets. (See pic. P & C 1992 p. 479).

13. Time to reproductive maturity? Produce first flowers when about two years old. (Parsons and Cuthbertson, 1992)

DISPERSAL

14. Number of mechanisms? Pods bursting and ejecting seeds. Also seed movement by vehicles, equipment, agricultural products, mud, etc. Perhaps birds? And animals.Parsons and Cuthbertson, 1992; DPI Tas., 1992)

15. How far do they disperse? Most seeds likely ejected from seed pods on hot summer days, with seeds only being flung 2 m from the parent plant. (DPI Tas., 1992)

Impact Assessment

RECREATION

1. Restrict human access? Evergreen plant that can dominate the shrub canopy and grow to 3 metres high and wide. It grows in a variety of natural habitats including forest margins and riparian areas. It was used as a hedge plant. In dense infestations it would present a significant barrier to both humans and vehicles. (Muyt, 2001)

2. Reduce tourism? Infestations in natural ecosystems would restrict some recreational activities. (Muyt, 2001)

3. Injurious to people? The seeds are highly poisonous. (Blood, 2001)

4. Damage to cultural sites? The root system is not vigorous and is unlikely to cause structural damage. “Brooms are highly invasive, commonly invading disturbed bushland margins before expanding into less disturbed areas.” The presence of G. monspessulana would be very noticeable particularly during flowering, which would seriously affect the aesthetics of a cultural site. (Parsons and Cuthberton, 2001; Muyt, 2001)

ABIOTIC

5. Impact flow? Terrestrial species. Although it does occur in riparian areas, there is no documented evidence of its affecting water flow. (Parsons and Cuthbertson, 2001)

6. Impact water quality? Not known to affect water quality

7. Increase soil erosion? An evergreen plant that provides extensive vegetative cover; branched taproot with numerous shallow lateral roots. This plant would not contribute to soil erosion. (Muyt, 2001)

8. Reduce biomass? Generally invades disturbed. With its growth habit biomass may increase. (Muyt, 2001)

9. Change fire regime? It is a fire hazard in forest areas where it can form “an inflammable understorey at the edge of forests where fires are most likely to start.” High potential to change the frequency of fire risk.

COMMUNITY HABITAT

10(a) Impact on composition of high value EVC? EVC=Valley grassy forest (E); CMA=West Gippsland; Bioreg=Highlands – Southern Fall; VH CLIMATE potential.
“Infestations shade and crowd out smaller shrubs and ground-flora species, eventually dominating the shrub canopy and severely impeding overstorey regeneration.” Serious impact on lower and mid strata. (Muyt, 2001)

10(b) Impact on medium value EVC? EVC=Heathy woodland (D); CMA=Glenelg Hopkins; Bioreg=Central Victorian Uplands; VH CLIMATE potential. Impact as in 10(a) above. (Muyt, 2001)

10(c) Impact on low value EVC? EVC=Heathy Woodland (LC); CMA=Glenelg Hopkins; Bioreg=Glenelg Plain; VH CLIMATE potential. Impact as in 10(a) above. (Muyt, 2001)

11. Impact on structure? “Infestations shade and crowd out smaller shrubs and ground-flora species, eventually dominating the shrub canopy and severely impeding overstorey regeneration.” Potential to serious affect lower and mid-storey species. (Muyt, 2001)

12. Effect on threatened flora?

FAUNA

13. Effect on threatened fauna?

14. Effect on non-threatened fauna? “Dense thickets exclude most other plants and thus affect the carrying capacity.” It is widespread in medium to large populations. Its capacity to invade a broad range of vegetative communities including grasslands, woodlands, heathlands, forests and riparian areas and its potential to dominate indicates the plant is likely to have a major impact on the food sources of native fauna. (Parsons and Cuthbertson, 2001; Muyt, 2001; Carr et al., 1992)

15. Benefits fauna? No recorded benefits. The plant may provide harbor for some species. (Parsons and Cuthbertson, 2001; Blood, 2001)

16. Injurious to fauna? Seeds are highly poisonous (Blood, 2001).

PEST ANIMAL

17. Food source to pests? Not known as a food source to pest animals.

18. Provides harbor? It “affords cover for pest animals such as rabbits.” (Parsons and Cuthbertson, 2001)

AGRICULTURE

19. Impact yield? Its effect in agricultural situations is limited as it mostly occurs in poorer pastures. In these situations, however, “it forms dense thickets, which exclude most other vegetation and thus affect the carrying capacity.” It would have at least a minor impact on yield. (Parsons and Cuthbertson, 2001)

20. Impact quality? The plant reproduces sexually and takes about two years to reach sexual maturity. The plant would not develop in cultivated situations. (Parsons and Cuthbertson, 2001)

21. Affect land values? On arable land control is easily effected by mechanical means. Not likely to affect land value. (Parsons and Cuthbertson, 2001)

22. Change land use? Not a serious weed of agriculture. Control is easily effected by mechanical means.. (Parsons and Cuthbertson, 2001)

23. Increase harvest costs? Not known.

24. Disease host/vector? None evident.

Feedback:

Do you have additional information about this plant that will improve the quality of the assessment? If so, we would value your contribution.

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

The entry of this assessment was made possible through the generous support of an anonymous donor.

Attachments:

17752_large.jpg
Cape via ala.JPG
distribution_map (28).png

referenced by (2)

wra1009: Common Name - M (via Montpellier broom)wra997: Common Name - C (via Cape broom)

Article: wra1589 (permalink)
Categories: :wra:g, :wra:inv1, :wra:invmh, :wra:inv2, :wra:inv3, :wra:invh, :wra:inv4, :wra:inv5, :wra:invl, :wra:inv6, :wra:inv7, :wra:inv8, :wra:inv9, :wra:invml, :wra:inv10, :wra:inv11, :wra:inv12, :wra:inv13, :wra:inv14, :wra:inv15, :wra:invm, :wra:imp1, :wra:imph, :wra:imp2, :wra:impmh, :wra:imp3, :wra:imp4, :wra:impl, :wra:imp5, :wra:imp6, :wra:imp7, :wra:imp8, :wra:imp9, :wra:imp10a, :wra:imp10b, :wra:imp10c, :wra:imp11, :wra:imp12, :wra:impm, :wra:imp13, :wra:imp14, :wra:imp15, :wra:imp16, :wra:imp17, :wra:imp18, :wra:imp19, :wra:impml, :wra:imp20, :wra:imp21, :wra:imp22, :wra:imp23, :wra:imp24
Date: 5 October 2009; 3:31:15 PM AEDT

Author Name: David Low
Author ID: adminDavid