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

Eucalyptus robusta; swamp mahogany

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

n

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

1

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

n

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

n

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

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

n

4.06

Host for recognized pests and pathogens

y=1, n=0

y

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

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

n

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

n

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

y

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

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

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

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

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

Total score:

3

Source

Notes

1.01

no evidence

1.02

Wagner et al. Flowering plants of Hawaii

"regenerating from seeds near plantings"

1.03

2.01

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

E. robusta occurs naturally in Australia, within a narrow coastal strip from southern New South Wales (near Nowra) to coastal south-eastern Queensland (north-west of Bundaberg). It is also grows on the offshore islands of North Stradbroke, Moreton and Fraser in south-east Queensland. A disjunct population occurs just north of Yeppoon in coastal, central Queensland.
Vegetation Types
E. robusta occurs mainly in open-forest, where it is restricted to swamps, edges of saltwater estuaries and lagoons, or rarely on the lower slopes of valleys (Fenton et al., 1977; Boland et al., 1984). This species forms pure stands or may be associated with other eucalypts such as E. resinifera, E. gummifera (syn. Corymbia gummifera), E. intermedia (syn. Corymbia intermedia) and sometimes E. tereticornis. Other trees found growing with E. robusta include various species of Melaleuca and Casuarina glauca. These tend to replace E. robusta on sites with very high water tables.
Natural latitude range
Approximate limits north to south

2.02

2.03

(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://pppis.fao.org/

(1)E. robusta occurs mainly in open-forest, where it is restricted to swamps, edges of saltwater estuaries and lagoons, or rarely on the lower slopes of valleys (Fenton et al., 1977; Boland et al., 1984).
E. robusta occurs naturally in the warm humid climate zone, ranging from regions with a with rare winter frosts and a summer maximum, to a uniform distribution of rainfall throughout the year (Boland et al., 1984). A bioclimatic analysis of the natural distribution of the species is given by Booth et al. (1988), and revised climatic profiles after inclusion of data from successful trials are also available (Webb et al., 1984; Booth et al., 1988; Marcar et al., 1995).
E. robusta grows well on sites in the moist tropics up to an elevation of 1600 m, and with a mean annual temperature of about 23C. It inhabits areas with a rainfall in excess of 1500 mm, which is distributed fairly uniformly throughout the year. However, this species has a wide ranging physiological adaptability, and may establish successfully o

2.04

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

Climate
E. robusta occurs naturally in the warm humid climate zone, ranging from regions with a with rare winter frosts and a summer maximum, to a uniform distribution of rainfall throughout the year (Boland et al., 1984). A bioclimatic analysis of the natural distribution of the species is given by Booth et al. (1988), and revised climatic profiles after inclusion of data from successful trials are also available (Webb et al., 1984; Booth et al., 1988; Marcar et al., 1995).
E. robusta grows well on sites in the moist tropics up to an elevation of 1600 m, and with a mean annual temperature of about 23C. It inhabits areas with a rainfall in excess of 1500 mm, which is distributed fairly uniformly throughout the year. However, this species has a wide ranging physiological adaptability, and may establish successfully on sites of much lower rainfall (min. value 700 mm). Mature trees of E. robusta are remarkably tolerant of frost, especially given that frosts are uncommon in the species' natural range. For exampl

2.05

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

Location of introductions
E. robusta is a very adaptable species, and has been established successfully over a remarkable range of environments from equatorial regions to an approximate latitude 35刨 (Penfold and Willis, 1961; Streets, 1962; Pryor, 1976; Fenton et al., 1977; Poynton, 1979; Jacobs, 1981; Turnbull and Pryor, 1984; Durst, 1988). Pryor (1976) lists E. robusta as one of the eucalypt species most commonly planted outside Australia. Significant areas of E. robusta are planted in Madagascar, Mozambique, Papua New Guinea, Sri Lanka and Hawaii (Jacobs, 1981).

3.01

Wagner et al. Flowering plants of Hawaii

"regenerating from seeds near plantings"

3.02

no evidence

3.03

no evidence

3.04

Weeds Gone Wild: Alien Plant Invaders of Natural Areas.
Webpage avialable at:<Vhttp://www.nps.gov/plants/alien/index.htm>

E. robusta was on the plant list. [No evidence: this list is notorious for it's incacurate information -- list is assembled from unreviewed input anyone]

3.05

Bacon, P. (Project coordinator) (1997) An electronic atlas of weeds and invasive species.Version 1.0 May 1997. (Based on the original work "Holm, L.; J.V. Puncho; J.P. Herberger & D.L. Plucknett (1979) A Geographical Atlas of World Weeds. John Wiley & Sons, Inc." )

E. campageana, E. ferruginea, E. gracilis, E. marginata, E. miniata, e. pilularis, E. populnea, and E. tetradonta were listed as principal weeds in Australia (native habitat)

4.01

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

no description of these traits

4.02

Chou, C.-H. (1980) Allelopathic researches in the subtropical vegetation in Taiwan. Comparative Physiology and Ecology, 1980, Vol.5, No.4, pp.222-234, many ref.

AB: "The species that exhibited allelopathy or allelopathic-like patterns included Acacia confusa, Bauhinia purpurea, Eucalyptus robusta, Glochidion fortueni, Phyllostachys spp." [don't know about field situations]

4.03

no evidence

4.04

USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Plant characteristics\ Palatable Browse Animal: Low

4.05

no evidence

4.06

Barnard, E. L. (1984) Occurrence, impact, and fungicidal control of girdling stem cankers caused by Cylindrocladium scoparium on eucalyptus seedlings in a south Florida nursery. Plant Disease, 1984, Vol.68, No.6, pp.471-473, 15 ref.

AB: "C. scoparium caused extensive losses of Eucalyptus grandis and E. robusta seedlings by inducing girdling cankers on the lower stems."

4.07

no evidence

4.08

no evidence

4.09

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

":As with other species in the genus, E. robusta is intolerant of shade "

4.1

(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://www.australiaplants.com/Eucalyptus_robusta.htm

(1)E. robusta is highly tolerant to seasonal waterlogging. It occurs mainly on margins of swamps, and on the fringes of salt water estuaries or lagoons. Soils are typically heavy clays, but also light sandy clays (Marcar et al., 1995). On the offshore islands of south-east Queensland, such as Fraser Island, it is found on almost pure sands (Boland et al., 1984).
- Soil texture: light; heavy
- Soil drainage: seasonally waterlogged
- Soil reaction: very acid; acid; neutral
- Special soil tolerances: saline
- Soil types: clay soils; sandy soils (2)can grow in most any type soil.

4.11

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

"E. robusta is a medium to large tree with a dense crown and long, spreading branches when open grown. It regularly attains heights of 20-30 m, with a d.b.h. of up to 1 m (Boland DJ, Brooker MIH, Chippendale GM, Hall N, Hyland BPM, Johnston RD, Kleinig DA, Turner JD, 1984. Forest trees of Australia. 4th ed. Melbourne:Thomas Nelson and CSIRO. xvi + 687 pp.; 77 ref.)."

4.12

no evidence

5.01

terrestrial

5.02

tree; Myrtaceae

5.03

no evidence

5.04

tree

6.01

no evidence

6.02

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

"Seed is the main means of propagating E. robusta."

6.03

no evidence

6.04

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

"They reproduce by a mixed mating system, with both outcrossing and selfcrossing (Moran GF, 1992. Patterns of genetic diversity in Australian tree species. New Forests, 6:49-66.)."

6.05

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

"Eucalypts have hermaphrodite, protandrous flowers and are primarily pollinated by insects and birds (Griffin AR, 1989. Strategies for the genetic improvement of yield in Eucalyptus. In: Pereira JS, Landsberg JJ, eds. Biomass production by fast-growing trees. Dordrecht, Germany: Kluwer, 247-265.). "

6.06

no evidence

6.07

(1)CAB International, (2000) Forestry Compendium Global Module. Wallingford, UK: CAB International. (2)http://newcrop.hort.purdue.edu/newcrop/duke_energy/Eucalyptus_robusta.html

(1) It has been reported to flower after 2 years in Kenya (Jacobs MR, 1981. Eucalypts for planting. Ed. 2. Forestry Series No. 11. Rome: FAO xxiv + 677 pp. + 36 pl.), and after 5 years in California (King JP, Krugman SL, 1980. Tests of 36 Eucalyptus species in northern California. Research-Paper,-Pacific-Southwest-Forest-and-Range-Experiment-Station,-USDA-Forest-Service. 1980, No. PSW-152, ii + 6 pp.; 1 pl.; 5 ref.). (2)In Malaysia, it starts fruiting as early as year 4. Fruits take two years to ripen in China. Fruits are collected when the capsules start to turn black.

7.01

no evidence

7.02

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

Location of introductions
E. robusta is a very adaptable species, and has been established successfully over a remarkable range of environments from equatorial regions to an approximate latitude 35刨 (Penfold and Willis, 1961; Streets, 1962; Pryor, 1976; Fenton et al., 1977; Poynton, 1979; Jacobs, 1981; Turnbull and Pryor, 1984; Durst, 1988). Pryor (1976) lists E. robusta as one of the eucalypt species most commonly planted outside Australia. Significant areas of E. robusta are planted in Madagascar, Mozambique, Papua New Guinea, Sri Lanka and Hawaii (Jacobs, 1981).

7.03

no evidence

7.04

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

here is an average of 452,000 viable seed per kilogram of seed and chaff mix (Turnbull JW, Doran JC, 1987. Seed development and germination in the Myrtaceae. In: Langkamp PJ, ed. Germination of Australian native plant seed, 46-57, 186-198; 57 ref.) [very small seeds]

7.05

no evidence

7.06

no evidence

7.07

no evidence

7.08

no evidence of ingestion

8.01

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

There is an average of 452,000 viable seed per kilogram of seed and chaff mix (Turnbull and Doran, 1987). Seedlots may be cleaned to a high level of purity by sieving. In order to separate the seed from the chaff a 12.6 /cm?mesh is required (Boland et al., 1980). [very small seeds]

8.02

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

"No pre-sowing treatment is required. Rapid and complete germination is achieved under moist, warm conditions in the presence of light (25C is optimal in the laboratory)"

8.03

no evidence

8.04

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

"This species recovers well after fire"

8.05

no evidence