Ochna (Ochna serrulata)

Present distribution

Scientific name:	Ochna serrulata (Hochst.) Walp.
Common name(s):	Ochna, Mickey Mouse plant

This weed is not known to be naturalised in Victoria

Habitat:

Native to Southern Africa. Reported in various habitats from grassland, to forest, to 1800m.

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:
Forest private plantation; forest public plantation; pasture dryland; pasture irrigation

Broad vegetation types
Coastal scrubs and grassland; coastal grassy woodland; heathy woodland; lowland forest; heath; swamp scrub; box ironbark forest; inland slopes and plains; sedge rich woodland; dry foothills forest; moist foothills forest; montane dry woodland; montane moist forest; sub-alpine woodland; grassland; plains grassy woodland; valley grassy forest; herb-rich woodland; sub-alpine grassy woodland; montane grassy woodland; riverine grassy woodland riparian forest; rainshadow woodland; mallee; mallee heath; mallee woodland; wimmera / mallee woodland

Colours indicate possibility of Ochna serrulata infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

Map showing the potential distribution of ochna

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	Planted as hedges, therefore can grow densely and impede access (Gosper, Vivian-Smith & Hoad 2006).	ml	h
2. Reduce tourism?	No specific data however it is planted as an ornamental may have some aesthetic impacts.	ml	ml
3. Injurious to people?	No spines or toxicity reported.	l	m
4. Damage to cultural sites?	Not reported to have invasive root system or other destructive growth. May have some visual impact.	ml	m
Abiotic
5. Impact flow?	Terrestrial species	l	m
6. Impact water quality?	Terrestrial species	l	m
7. Increase soil erosion?	No specific data however in the habitats it invades it is not reported to disrupt processes that would lead to an increase in erosion.	l	m
8. Reduce biomass?	Competitive species directly replacing other species or in the case of grassland increase biomass.	ml	m
9. Change fire regime?	No specific information on flammability and if biomass isn't altered significantly little change to fire regime should be recorded.	l	m
Community Habitat
10. Impact on composition (a) high value EVC	EVC= Damp Sands Herb-rich Woodland (V); CMA= West Gippsland; Bioreg Wilsons Promontory; H CLIMATE potential. Highly competitive species in shrub layer. Major displacement of dominant sp. within a layer.	mh	mh
(b) medium value EVC	EVC= Cool Temperate Rainforest (D); CMA= West Gippsland; Bioreg Wilsons Promontory; H CLIMATE potential. Highly competitive species in shrub layer. Major displacement of dominant sp. within a layer.	mh	mh
(c) low value EVC	EVC= Lowland Forest (LC); CMA= West Gippsland; Bioreg Wilsons Promontory; H CLIMATE potential. Highly competitive species in shrub layer. Major displacement of dominant sp. within a layer.	mh	mh
11. Impact on structure?	Reported to dominate the shrub layer (Gosper, Vivian-Smith & Hoad 2006).	m	h
12. Effect on threatened flora?	No specific data, however can become dominant in the shrub layer	mh	ml
Fauna
13. Effect on threatened fauna?	No specific data	mh	l
14. Effect on non-threatened fauna?	Fruit may be mimetic however do have some nutritional value (Gosper, Vivian-Smith & Hoad 2006).	ml	mh
15. Benefits fauna?	Provides figbirds with an alternate food source before other fruit becomes ripe (Gosper, Vivian-Smith & Hoad 2006).	mh	h
16. Injurious to fauna?	No toxicity of spines reported	l	m
Pest Animal
17. Food source to pests?	Produces food for frugivoruos birds (Gosper, Vivian-Smith & Hoad 2006).	ml	h
18. Provides harbour?	No specific data but presumed no more than any other shrub that it competes with.	m	l
Agriculture
19. Impact yield?	Not an agricultural weed, may attract frugivours that could then attack crops.	ml	ml
20. Impact quality?	Not an agricultural weed	l	m
21. Affect land value?	Not an agricultural weed	l	m
22. Change land use?	Not an agricultural weed	l	m
23. Increase harvest costs?	Not an agricultural weed	l	m
24. Disease host/vector?	Not an agricultural weed may harbour pests of fruit crops.	m	l

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	Ripe dupes are present between September and march with seeds germinating between 6 and 66 days after dropping to the ground or being dispersed by birds with natural light and moisture conditions. As seeds were found not to be viable after 12 months germination occurs on a seasonal bases (Gosper, Vivian-Smith & Hoad 2006).	mh	h
2. Establishment requirements?	A preference for light conditions has been show but it is not a requirement, providing moisture levels are not limiting seeds will germinate (Gosper, Vivian-Smith & Hoad 2006).	mh	h
3. How much disturbance is required?	Has invaded rainforest, dry sclerophyll forest and riparian vegetation (Gosper, Vivian-Smith & Hoad 2006).	mh	h
Growth/Competitive
4. Life form?	Perennial shrub (Gosper, Vivian-Smith & Hoad 2006).	l	h
5. Allelopathic properties?	None described	l	l
6. Tolerates herb pressure?	Not described, adapted to forest margins and grassland of southern Africa probably tolerant of a moderate level of browsing, no data on impact of heavy browsing ie. stock damage.	m	l
7. Normal growth rate?	A medium to large shrub, specific rate of growth not described.	m	l
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Occurs in the Northland, New Zealand and Lord Howe Island (Tolerant of Frost) Occurs in rainforest and riparian vegetation and seedling establishment limited by moisture content (Susceptible to drought) (Gosper, Vivian-Smith & Hoad 2006).	ml	m
Reproduction
9. Reproductive system	Produces seeds (Gosper, Vivian-Smith & Hoad 2006).	ml	m
10. Number of propagules produced?	One seed per dupe, a mean of 200-250 ripe dupes have been counted on plants near Brisbane. However fruit ripens from September to march (Gosper, Vivian-Smith & Hoad 2006).	m	mh
11. Propagule longevity?	Very little seed 0.75% was found to be viable after 6 months and none after 12 (Gosper, Vivian-Smith & Hoad 2006).	l	h
12. Reproductive period?	No data on longevity of individual plants, perennial shrub likely to live >10 years.	mh	l
13. Time to reproductive maturity?	Perennial shrub likely to take 2-3 years before it produces substantial crop of fruit.	ml	l
Dispersal
14. Number of mechanisms?	Produces shinny black fruit which is then dispersed by birds (Gosper, Vivian-Smith & Hoad 2006).	h	h
15. How far do they disperse?	Consumed by figbirds which have been reported to forage over distances exceeding 1km (Gosper, Vivian-Smith & Hoad 2006)	h	h

References

Gosper. C.R., Vivian-Smith. G. & Hoad. K. (2006) Reproductive ecology of invasive Ochna serrulata (Ochnaceae) in south-eastern Queensland. Australian Journal of Botany, 54. 43-52.

Global present distribution data references

Australian National Herbarium (ANH) 2006, Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, viewed Aug 28 2006, http://www.anbg.gov.au/avh/

Global Biodiversity Information Facility (GBIF) 2006, Global biodiversity information facility: Prototype data portal, viewed Aug 28 2006, http://www.gbif.org/

Gosper. C.R., Vivian-Smith. G. & Hoad. K. (2006) Reproductive ecology of invasive Ochna serrulata (Ochnaceae) in south-eastern Queensland. Australian Journal of Botany, 54. 43-52.

Pacific Island Ecosystem at Risk (PIER) 2005, , Hawaii Ecosystem at Risk, viewed Aug 28 2006, http://www.hear.org/Pier/wra/pacific/

Palgrave. K.C. (1981) Trees of Southern Africa. Moll. E.J. (ed) C. Struik. Cape Town.

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