Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service

Information on Risk Assessments
Original risk assessment

Acacia confusa

Answer

1.01

Is the species highly domesticated?

y=-3, n=0

N

1.02

Has the species become naturalized where grown?

y=-1, n=-1

Y

1.03

Does the species have weedy races?

y=-1, n=-1

N

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

2

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

N

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

Y

2.05

Does the species have a history of repeated introductions outside its natural range? y=-2

?=-1, n=0

Y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

Y

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

N

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

N

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

Y

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

Y

4.01

Produces spines, thorns or burrs

y=1, n=0

N

4.02

Allelopathic

y=1, n=0

Y

4.03

Parasitic

y=1, n=0

N

4.04

Unpalatable to grazing animals

y=1, n=-1

Y

4.05

Toxic to animals

y=1, n=0

4.06

Host for recognized pests and pathogens

y=1, n=0

N

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

N

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

N

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

4.1

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

Y

4.11

Climbing or smothering growth habit

y=1, n=0

N

4.12

Forms dense thickets

y=1, n=0

5.01

Aquatic

y=5, n=0

N

5.02

Grass

y=1, n=0

N

5.03

Nitrogen fixing woody plant

y=1, n=0

Y

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

N

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

N

6.02

Produces viable seed.

y=1, n=-1

y

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

6.05

Requires specialist pollinators

y=-1, n=0

N

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

N

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

N

7.02

Propagules dispersed intentionally by people

y=1, n=-1

Y

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

N

7.04

Propagules adapted to wind dispersal

y=1, n=-1

N

7.05

Propagules water dispersed

y=1, n=-1

N

7.06

Propagules bird dispersed

y=1, n=-1

N

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

N

7.08

Propagules survive passage through the gut

y=1, n=-1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

N

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

Y

8.03

Well controlled by herbicides

y=-1, n=1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

Y

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

N

Total score:

10

Source

Notes

1.01

Did not find any evidence that the species is a cultivar or that it differs from the wild species.

1.02

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

'…in Hawaii widely cultivated and now naturalized in dry to mesic, disturbed areas…'.

641

1.03

Did not find any evidence that the species has weedy subspecies, cultivars or varieties.

2.01

http://www.hear.org/pier/accon.htm

A native of the Northern Philippines, naturalized extensively in Taiwan, Okinawa, and Saipan.

2.02

2.03

(1) CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2) http://www.botany.hawaii.edu/faculty/cw_smith/aca_con.htm

INDICATE REASON (1) Altitude range is 50 to 800 m. (2) It thrives between sea level and 700 m elevation in dry and mesic habitats

2.04

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

'Native to Taiwan and Philippine Islands;… .'

641

2.05

http://www.hear.org/pier/scinames.htm

Micronesia: Commonwealth of the Northern Mariana Islands (Agiguan, Saipan, Rota, Tinian, volcanic Northern Mariana Islands (Sarigan)); Federated States of Micronesia (Pohnpei, Yap), Guam, Republic of Palau (Babeldaob, Koror) Hawaii, Florida

3.01

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

'…in Hawaii widely cultivated and now naturalized in dry to mesic, disturbed areas…'.

641

3.02

Did not find any evidence to this species being a weed.

3.03

Did not find any evidence to this species being a weed.

3.04

(1)Smith, C. W. 1985. Impact of alien plants on Hawaii's native biota. In Hawaii's terrestrial ecosystems: preservation and management, ed. C.P. Stone, J. M. Scott. Pgs 180 - 250. University of Hawaii Cooperative National Park Resource Studies Unit. Honolulu. University of Hawaii. (2)http://www.botany.hawaii.edu/faculty/carr/aca_con.htm (3)http://endangered.fws.gov/r/fr94530.html [from Federal Register February 25, 1994 (4)http://a257.g.akamaitech.net/7/257/2422/14mar20010800/edocket.access.gpo.gov/2003/03-11156.htm [Federal Register: June 17, 2003]

(1)Considered to be a serious pest by Smith (1985) in natural communities in Hawaii. (2)It reaches heights of 15 m and shades out most other plants. It thrives between sea level and 700 m elevation in dry and mesic habitats. Major infestations are found on the windward side and Wai'anae Mountains, O'ahu, and the north shore of East Maui. (3)A small tree, Acacia confusa (Formosa koa), was introduced to Hawaii for reforestation purposes and is naturalized in dry to mesic, disturbed habitats on most of the Hawaiian Islands (Smith 1985, Wagner et al. 1990). Acacia mearnsii (black wattle) was introduced as a cultivated plant and has naturalized on five islands in pastures and dry to mesic forests (Wagner et al. 1990). It threatens Exocarpos luteolus (T. Flynn, pers. comm., 1991). (4)The major threats to Chamaesyce celastroides var. kaenana are competition from the nonnative plant species Acacia confusa (Formosan koa)

183

3.05

Weed Control Manual 2000. Meister Publishing Co., Salem, MA.

Acacia rigidly, Acacia tortuosaand Acacia farnesiana are listed under weeds of pastures and rangeland. Tricopyr is the suggested herbicide for their control.

466

4.01

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

Species description does not include the presence of spines, thorns or burrs.

641

4.02

Journal-of-Chemical-Ecology. Dec., 1998; 24 (12) 2131-2150.

Aqueous extracts phytotoxic to alfalfa, Chinese cabbage & lettuce even at low conc of 0.5%. Field studies showed relatively lower biomass under A. confusa stands. Also soil collected from below A. confusa stands retarded seed germination compared to soil from adjacent grass patches.

abstract

4.03

Did not find any evidence to this species being parasitic.

4.04

http://www.agroforester.com/agfor/speciescharac.html

NOT suitable for fodder

4.05

http://www.shaman-australis.com/Website/subcat13.htm

All parts of this plant can be toxic and should not be ingested. Dried Acacia confusa stems were found to contain about 0.04% of N-Methyltryptamine and 0.02% of N,N-Dimethyltryptamine (DMT) [Arthur et al. 1967].

4.06

http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm Then click on Fungus- host distribution

Acacia confusa
Acumispora uniseptata: Taiwan - 7850
Ardhachandra aequilatera: Taiwan - 6867
Aspergillus sp.: HI - 1710
Beltraniella portoricensis: Taiwan - 7850
Calonectria crotalariae: HI - 1710
Camposporium japonicum: Taiwan - 7850
Cercospora acaciae-confusae: China - 8097; Taiwan - 786, 7983, 8303
Chaetendophragmia triangularia: Taiwan - 7850
Coriolus hirsutus: Taiwan - 8303
Coriolus polyzonus: China - 8097
Coriolus versicolor: Taiwan - 8303
Corticium salmonicolor: China - 8097
Daldinia concentrica: Taiwan - 8251, 8303
Drechslera sorokiniana: Taiwan - 7850
Fomes robustus: Taiwan - 8251, 8303
Fusariella formosana: Taiwan - 8359
Ganoderma applanatum: China - 8097
Ganoderma applomatum: Taiwan - 8303
Ganoderma lucidum: Philippines - 7983, 7983; Taiwan - 8303, 8303
Ganoderma rugosum: Taiwan - 8303
Ganoderma tropicum: China - 8097; Taiwan - 8303
Gyrothrix podosperma: Taiwan - 7850
Helicoma taiwanens

4.07

Did not find any evidence of it causing allergies in humans or being poisonous.

4.08

Smith, C. W. 1985. Impact of alien plants on Hawaii's native biota. In Hawaii's terrestrial ecosystems: preservation and management, ed. C.P. Stone, J. M. Scott. Pgs 180 - 250. University of Hawaii Cooperative National Park Resource Studies Unit. Honolulu. University of Hawaii.

'The plant is essentially fire resistant because fire will not carry under the tree due to the lack of fuel.'

183

4.09

No information on shade tolerance

4.1

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

'It grows fast and has great adaptability to a wide range of soils.'

4.11

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

It is a tree growing up to 15 m tall. No evidence of it having a smothering habit.

641

4.12

Tunison, T. J. & N. G. Zimmer. 1992. Success in controling localized alien plants in Hawaii Volcanoes National Park. In Alien plant invasions in native ecosystems of Hawaii. Management and research, ed. C. P. Stone, C. W. Clifford & J. T. Tunison. Pgs 506 2)http://www.hear.org/pier/accon.htm

Approximately 370 individuals were found growing over 500 hectares in Hawaii Volcanoes national park [suggesting that it was not growing as dense thickets. No further evidence.] 2)In Hawai’i, it was planted for windbreaks on Maui and has since formed monotypic stands at lower elevations and continues to spread up to 1000 m (Randy Bartlett, communication on Aliens list server).

507

5.01

Fabaceae

5.02

Fabaceae

5.03

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

It is a nitrogen fixing tree.

641

5.04

Fabaceae

6.01

No evidence

6.02

Grown from seedlings

6.03

No information

6.04

No information

6.05

http://www.hear.org/pier/accon.htm

flowers are yellow globose heads and probably are pollinated by bees like most other Acacia species. [insect pollination syndrome]

6.06

http://www.hear.org/pier/accon.htm

No evidence of natural propagation through vegetation means, however it can be grown from cuttings.

6.07

No information

7.01

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

The propagules do not have any means of attachment and hence it is unlikely that the species will be dispersed unintentionally.

641

7.02

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

The species is grown for ornamental purposes and hence it is likely that it may be introduced intentionally by people.

7.03

http://www.hear.org/pier/accon.htm

Seed size is approximately 0.625 to 1 cm and hence less likely to be introduced as a produce contaminant.

7.04

Smith, C. W. 1985. Impact of alien plants on Hawaii's native biota. In Hawaii's terrestrial ecosystems: preservation and management, ed. C.P. Stone, J. M. Scott. Pgs 180 - 250. University of Hawaii Cooperative National Park Resource Studies Unit. Honolulu. University of Hawaii.

' The small seeds are passively dispersed.' [no clear adaptations for wind]

183

7.05

No evidence

7.06

No evidence

7.07

Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

The seeds do not have hooks and are neither sticky. Hence it is unlikely that it will be dispersed by attachment to animals.

641

7.08

No evidence of seeds being eaten by animals but hard seed coat could survive ingestion.

8.01

http://www.hear.org/pier/accon.htm

On calculation the seed size is about 1 cm and hence it is unlikely the seed productions is >1000 seeds/m sq.

8.02

http://www.hear.org/pier/accon.htm

Seeds present in the ground can germinate profusely after fire. [this legume has hard seed coat and dormancey]

8.03

(1)Tunison, T. J. & N. G. Zimmer. 1992. Success in controling localized alien plants in Hawaii Volcanoes National Park. In Alien plant invasions in native ecosystems of Hawaii. Management and research, ed. C. P. Stone, C. W. Clifford & J. T. Tunison. Pgs 506-524. University of Hawaii Press. Honolulu. (2)Kuo, P. C.; Wang, T. K.; I, C. C. 1973. The effects of herbicides on the growth of seedlings of some Taiwan hardwoods and on weed control. Quarterly Journal of Chinese Forestry, 6:.17-27

(1)The localized populations in the HVNP were eradicated by using 5% Garlon 4/diesel. (2)Test were made on seven herbicides: Alipur [cycluron + chlorbufam], Eptam [EPTC], Kloben[neburon], Tok [nitrofen], Herban [noruron], propazine, and Treflan [trifluralin]. Alipur, noruron and nitrofen were applied both before sowing (in Apr.) and after sowing (in Nov. and again in Dec.); EPTC and trifluralin were applied only before sowing, in combination with neburon applied only after sowing, and propazine was applied only in combination with another series of EPTC (or trifluralin)/neburon treatments.All the herbicides were tolerated by Acacia confusa.

514

8.04

Smith, C. W. 1985. Impact of alien plants on Hawaii's native biota. In Hawaii's terrestrial ecosystems: preservation and management, ed. C.P. Stone, J. M. Scott. Pgs 180 - 250. University of Hawaii Cooperative National Park Resource Studies Unit. Honolulu. University of Hawaii.

'Aerial portions which are only scorched will resprout rapidly.'

183

8.05

Has spread substantially in Hawaii. No evidence that this species is controlled by any effective pests. Some seeds attacked by weevils