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

Casuarina equisetifolia (iron wood, whistling pine)

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

y

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

n

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

n

4.05

Toxic to animals

y=1, n=0

n

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

y

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

y

4.09

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

y=1, n=0

n

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

y

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

y

6.04

Self-compatible or apomictic

y=1, n=-1

n

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

6.07

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

See left

3

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

y

7.05

Propagules water dispersed

y=1, n=-1

y

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

n

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

8.02

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

y=1, n=-1

n

8.03

Well controlled by herbicides

y=-1, n=1

y

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:

15

Source

Notes

1.01

No evidence.

1.02

C. equisetifolia has been introduced to more than 60 countries and is now a common feature of the coastal landscape of most tropical and subtropical countries, where it is often naturalized. These include the Caribbean, Mexico, central and south America, west and east Africa and elsewhere in Asia. (2)Naturalized in Hawaii.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

1.03

No evidence.

2.01

'This is a species of warm to hot subtroopical and tropical climates.'

Casuarinas: Nitrogen fixing trees for aadverse sites. 1984. National Academy press. Washington D.C.

2.02

2.03

This distribution covers a latitude range of 40 degrees between 20°N and 20°S. Approximate limits north to south: 20°N to 32°S. Altitude range: 0 - 1500 m (planted only??) 2) Although C. equisetifolia is generally a lowland tree, it grows at altitudes up to about 600 m in Hawaii

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. 2)http://www.winrock.org/forestry/factpub/FACTSH/C_equisetifolia.html

2.04

(1)Native to Australia and the Pacific Islands. (2)C. equisetifolia has been introduced to more than 60 countries and is now a common feature of the coastal landscape of most tropical and subtropical countries, where it is often naturalized. These include the Caribbean, Mexico, central and south America, west and east Africa and elsewhere in Asia.

(1)Horticopia. Trees, shrubs and groundcovers. (2)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.

2.05

C. equisetifolia has been introduced to more than 60 countries and is now a common feature of the coastal landscape of most tropical and subtropical countries, where it is often naturalized. These include the Caribbean, Mexico, central and south America, west and east Africa and elsewhere in Asia.

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

3.01

C. equisetifolia has been introduced to more than 60 countries and is now a common feature of the coastal landscape of most tropical and subtropical countries, where it is often naturalized. These include the Caribbean, Mexico, central and south America, west and east Africa and elsewhere in Asia. (2)Naturalized in Hawaii.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.

3.02

No evidence.

3.03

No evidence.

3.04

(1)It has the potential to become a weed under certain conditions. This has occurred in Hawaii and in the Florida peninsula of USA. It has colonized disturbed native vegetation formations and interfered in the nesting of sea turtles on foreshore dunes. (2)It forms monotypic stands under which little else grows. The lack of undergrowth prevents very hot fires from burning in the vicinity of these trees. When fires do sweep through stands, trees regenerate rapidly from basal shoots. (3)"Shoots and saplings sensitive to foliar applications of triclopyr. Trees sensitive to cut-surface applications of glyphosate, dicamba, picloram (45) and, based on response of saplings to foliar applications, probably sensitive to cut-surface applications of triclopyr." (Motookaet al., 2002) [subjected to control in Hawaii; Motooka, P., L. Castro, D. Nelson, G. Nagai and L. Ching . 2002. Weeds of pastures and natural areas of Hawaii and their management, UHCTAHR, Honolulu]

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://www.botany.hawaii.edu/faculty/cw_smith/cas_equ.htm (3)http://www.hear.org/pier/species/casuarina_equisetifolia.htm

3.05

C. glauca is considered a pest in Florida

NAS (National Academy of Sciences). 1984. Casuarinas: Nitrogen-fixing trees for adverse sites. Innovations in tropical reforestation. National Academy Press, Washington, D.C

4.01

No evidence.

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

4.02

Not allelopathic.

http://plants.usda.gov/cgi_bin/topics.cgi

4.03

No evidence.

4.04

Cattle, sheep and goats will graze C. glauca seedlings, suckers, and branchiets. The ground foliage has been included as an ingredient in chicken feed (El-Deek et al. 1988). C. equisetifolia presumed to be the same.

http://www.winrock.org/forestry/factpub/FACTSH/C_glauca.html

4.05

Not toxic.

http://plants.usda.gov/cgi_bin/topics.cgi

4.06

None of major concern. (2)List of 88 fungi occurring on C. equisetifolia (3)Seeds are carried off in large quantities by ants. Seeds and seedlings are attacked by insects and crabs. It suffers from many fungal diseases. (4)In Malaya it does not appear to suffer from pests although it harbors Icerya purchasi, a pest of orange and lemon.

Horticopia. Trees, Shrubs and groundcovers. (2)http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm (3)and (4)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm

4.07

The large quantities of air-borne pollen cause respiratory irritations. (2)Root extracts are used for medical treatment of dysentery, diarrhoea and stomach-ache. (3)The trees also shed hard pointed "cones" that make walking barefoot under them an unpleasant experience. And, Casuarina pollen can cause allergic reactions such as respiratory problems, eye irritation, rhinitis, and/or hoarseness.

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm(2)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (3)http://www.floridata.com/ref/C/casu_equ.cfm

4.08

(1)It is sensitive to fire. (2)High flammability.
Accumulation of thick ground litter layer

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)Horticopia. Trees, Shrubs and groundcovers.

4.09

C. equisetifolia is shade intolerant. (2)A light demanding species which needs open sites for establishment

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm

4.1

(1)Soil types: calcareous soils; sandy soils. It grows well in soils with a pH from 5.0 to 9.5. (2)Clay, sandy, loam well drained. (3)Sandy, clay, loam and rocky.

(1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)Horticopia. Trees, Shrubs and groundcovers. CD ROM database. (3)Plant master 5.5 CD ROM database.

4.11

It is not a vine. No evidence of smothering habit.

4.12

It often forms dense stands which are nearly impossible to walk through.

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm

5.01

5.02

5.03

C. equisetifolia is a nitrogen-fixing tree …

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

5.04

6.01

No evidence.

6.02

Germination rate varies between 30 and 84 % but seeds are only viable for a few months

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm

6.03

'The presence of hybrids is a cause of uncertainty in readily distinguishing these species at a distance. Natural hybridization and differences in nomenclature make American literature on the subject confusing (Woodall and Geary 1985, Long and Lakela 1971).'

http://tncweeds.ucdavis.edu/esadocs/documnts/casuequ.html

6.04

Although trees in natural stands are reported to be mostly monoecious, with male and female flowers separate but borne on the same tree, most cultivated populations are predominantly dioecious

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

6.05

Pollination is by wind.

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

6.06

Root suckering occurs.

Casuarinas: Nitrogen fixing trees for aadverse sites. 1984. National Academy press. Washington D.C.

6.07

The age to first flowering varies from 2 to 5 years 2)Males trees flower at 2-3 years of age and female trees produce fruits one year later.

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. 2)http://www.winrock.org/forestry/factpub/FACTSH/C_glauca.html

7.01

Propagules have no means of attachment.

7.02

This species does not have ornamental value not does it produce edible fruits.

7.03

no produce

Pinyopusarek, K. and House, A.P.N. 1993. Casuarina an annotated bibliography of C. equisetifolia, C. junghuhniana and C. oligodon. International center for research in agroforestry . English Press. Nairobi.

7.04

Female cones mature about 18-20 weeks after anthesis, and will release small samara (winged seeds) within 3 days

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

7.05

Some dispersal of seed (in cones or after release from cones) may be affected by water, ensuring the spread of the species along sea shores.

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

7.06

7.07

Propagules have no means of

7.08

Propagules are wind and sometimes water dispersed.

8.01

A kilogram of cones (about 250 cones) yields 20-60 g of seed. There are about 650-760 seeds per gram but on average only 270 seeds are viable. 2)averages 70 seeds/cone (C. glauca)

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. 2)http://www.winrock.org/forestry/factpub/FACTSH/C_glauca.html

8.02

Germination rate varies between 30 and 84 % but seeds are only viable for a few months (unless stored under amenable laboratory conditions)

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm

8.03

'Its threat to the Everglades National Park was quickly realized and a control program was initiated. Seedlings were easily uprooted and larger trees killed by cutting or girdling and treated with the herbicides. However, the herbicides used in the 1960s, 2,4,5-T and 2,4-D, were and other herbicides have since been used with limited success. The spread of the species had been contained by the early 1980s but as seeds are continuously brought in from mature stands inside and outside the park, continuing seedling control is required.'

http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm

8.04

The ability to coppice is limited, and is usually restricted to trees up to 4 years old (Yantasath et al., 1985); however, trees respond reasonably well to hedging. (2)Does not suffer from browsing. When cut the tree sprouts profusely

CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://members.lycos.co.uk/WoodyPlantEcology/docs/web-sp2.htm

8.05

Forms dense stands in Hawaii.