Pacific Island Ecosystems at Risk (PIER)


Eucalyptus saligna


RISK ASSESSMENT RESULTS: High risk, score: 7


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment
  Eucalyptus saligna (sydney blue gum, blue gum) Answer Score
1.01 Is the species highly domesticated? n 0
1.02 Has the species become naturalized where grown? y  
1.03 Does the species have weedy races? 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” 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
2.04 Native or naturalized in regions with tropical or subtropical climates y 1
2.05 Does the species have a history of repeated introductions outside its natural range?  y=-2 y  
3.01 Naturalized beyond native range         y = 1*multiplier (see Append 2), n= question 2.05 y 2
3.02 Garden/amenity/disturbance weed                              y = 1*multiplier (see Append 2) n 0
3.03 Agricultural/forestry/horticultural weed                         y = 2*multiplier (see Append 2) n 0
3.04 Environmental weed                                                     y = 2*multiplier (see Append 2) n 0
3.05 Congeneric weed                                                          y = 1*multiplier (see Append 2) y 2
4.01 Produces spines, thorns or burrs n 0
4.02 Allelopathic y 1
4.03 Parasitic n 0
4.04 Unpalatable to grazing animals n -1
4.05 Toxic to animals n 0
4.06 Host for recognized pests and pathogens n 0
4.07 Causes allergies or is otherwise toxic to humans n 0
4.08 Creates a fire hazard in natural ecosystems n 0
4.09 Is a shade tolerant plant at some stage of its life cycle n 0
4.1 Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island) y 1
4.11 Climbing or smothering growth habit n 0
4.12 Forms dense thickets n 0
5.01 Aquatic n 0
5.02 Grass n 0
5.03 Nitrogen fixing woody plant n 0
5.04 Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers) n 0
6.01 Evidence of substantial reproductive failure in native habitat n 0
6.02 Produces viable seed. y 1
6.03 Hybridizes naturally y 1
6.04 Self-compatible or apomictic y 1
6.05 Requires specialist pollinators n 0
6.06 Reproduction by vegetative fragmentation n -1
6.07 Minimum generative time (years)                 1 year = 1, 2 or 3 years = 0, 4+ years = -1 3 0
7.01 Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) n -1
7.02 Propagules dispersed intentionally by people y 1
7.03 Propagules likely to disperse as a produce contaminant n -1
7.04 Propagules adapted to wind dispersal y 1
7.05 Propagules water dispersed n -1
7.06 Propagules bird dispersed n -1
7.07 Propagules dispersed by other animals (externally) n -1
7.08 Propagules survive passage through the gut n -1
8.01 Prolific seed production (>1000/m2) y 1
8.02 Evidence that a persistent propagule bank is formed (>1 yr)    
8.03 Well controlled by herbicides    
8.04 Tolerates, or benefits from, mutilation, cultivation, or fire y 1
8.05 Effective natural enemies present locally (e.g. introduced biocontrol agents)    
  Total score:   7

Supporting data:

  Notes Reference
1.01 No evidence.  
1.02 (1)Naturalized in Hawaii.  (2)Naturalzied in New Zealand. (1)Wagner, W. L., Herbst, D. R. and Sohmer, S H. Manual of flowering plants of Hawaii. University of Hawaii Press. Vol 1 Page 958.  (2)Webb, C.J. et al. 1988. Flora of New Zealand. Vol IV. Naturalized Pteridophytes, Gymnosperms, Dicotyledons. Singapore National Printers Limited. Page 862.
1.03 No evidence  
2.01 (1)'List of countries with natural populations -Oceania, [Australia], New South Wales, Queensland. … Jacobs (1981) estimated that by the late 1970's at least half a million hectares of successful E. saligna plantations had been established outside of Australia and particularly in countries in South America and southern Africa and in India and Sri Lanka. It has also experienced some success in the warmer parts of both the North and South Islands of New Zealand (McKenzie and Hay, 1996). Seed of the species has been very widely distributed for trial plantings...'   (2) 'Saligna eucalyptus is native to the east coast of Australia from Bateman's Bay (lat. 36 S.) in southern New South Wales to the southeastern corner of Queensland (lat. 27 S.) (13).' (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
2.02 (1)'List of countries with natural populations -Oceania, [Australia], New South Wales, Queensland. … Jacobs (1981) estimated that by the late 1970's at least half a million hectares of successful E. saligna plantations had been established outside of Australia and particularly in countries in South America and southern Africa and in India and Sri Lanka. It has also experienced some success in the warmer parts of both the North and South Islands of New Zealand (McKenzie and Hay, 1996). Seed of the species has been very widely distributed for trial plantings...'   (2) 'Saligna eucalyptus is native to the east coast of Australia from Bateman's Bay (lat. 36 S.) in southern New South Wales to the southeastern corner of Queensland (lat. 27 S.) (13).' (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
2.03   - Altitude range: 0 - 2100 m
  - Mean annual rainfall: 700 - 1800 mm
  - Rainfall regime: summer; winter; bimodal; uniform
  - Dry season duration: 0 - 6 months
  - Mean annual temperature: 14 - 23C
  - Mean maximum temperature of hottest month: 22 - 32C
  - Mean minimum temperature of coldest month: 1 - 14C
  - Absolute minimum temperature: > -8C
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
2.04 List of countries with natural populations -Oceania, [Australia], New South Wales, Queensland. … Jacobs (1981) estimated that by the late 1970's at least half a million hectares of successful E. saligna plantations had been established outside of Australia and particularly in countries in South America and southern Africa and in India and Sri Lanka. It has also experienced some success in the warmer parts of both the North and South Islands of New Zealand (McKenzie and Hay, 1996). Seed of the species has been very widely distributed for trial plantings...' CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
2.05 (1)'List of countries with natural populations -Oceania, [Australia], New South Wales, Queensland. … Jacobs (1981) estimated that by the late 1970's at least half a million hectares of successful E. saligna plantations had been established outside of Australia and particularly in countries in South America and southern Africa and in India and Sri Lanka. It has also experienced some success in the warmer parts of both the North and South Islands of New Zealand (McKenzie and Hay, 1996). Seed of the species has been very widely distributed for trial plantings...'  (2)In the United States, it has been introduced into Florida, California, and Hawaii. In Hawaii it reproduces at the edges of planted stands. Although it was introduced into Hawaii in the late 1800's, the tree was not planted extensively until the 1960's, when it became the principal tree used for forestation. (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
3.01 (1)Naturalized in Hawaii.  (2)Naturalzied in New Zealand. (1)Wagner, W. L., Herbst, D. R. and Sohmer, S H. Manual of flowering plants of Hawaii. University of Hawaii Press. Vol 1 Page 958.  (2)Webb, C.J. et al. 1988. Flora of New Zealand. Vol IV. Naturalized Pteridophytes, Gymnosperms, Dicotyledons. Singapore National Printers Limited. Page 862.
3.02 No evidence.  
3.03 No evidence.  
3.04 No evidence  
3.05 Severa Eucalyptus species such as E. populnea,E.  pilularis, E. ferruginear and E. cambageana are listed as principal weeds in Australia.  An electronic Atlas of Weeds and Invasive Species. CD ROM version 1. 1997. Based on the original work 'A Geographical Atlas of Weeds' by Holm et al.
4.01 No evidence of such structures. (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
4.02 (1)Allelopathic.  (2)Abstract: The potential allelopathic effect of Cupressus lusitanica, Eucalyptus globulus, E. camaldulensis and E. saligna on seed germination, radicle and seedling growth was investigated with four crops: Cicer arietinum (chickpea), Zea mays (maize), Pisum salivum (pea) and Eragrostis tef (teff). Aqueous leaf extracts of all the tree species significantly reduced both germination and radicle growth of the majority of the crops mostly starting from concentrations of 1% or 2.5%. The shoot and root dry weight increase of the crops was significantly reduced after 10 weeks treatment with leaf extracts. Among the four crops, chickpea and teff were most susceptible with respect to germination, and teff with respect to growth. From the overall data the leaf extracts of the four tree species can be arranged according to increasing allelopathic potential: C. lusitanica, E. globulus, saligna and E. camaldulensis. It is suggested that the planting of E. camaldulensis and E. saligna in integrated land use systems should be minimized, whereas the use of C. lusitanica and E. globulus seems less environmentally damaging in this respect. (1)http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=EUSA  (2) Lisanework, N.; Michelsen, A. Allelopathy in agroforestry systems: The effects of leaf extracts of Cupressus lusitanica and three Eucalyptus spp. on four Ethiopian crops Agroforestry Systems 21 (1) : 63-74 1993.
4.03 No evidence  
4.04 Low palatability to browse animals. http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=EUSA
4.05 No toxicity. http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=EUSA
4.06  'Pests recorded
Insect pests:
Phoracantha semipunctata
Phylacteophaga froggatti
Fungus diseases:
Cryphonectria cubensis [1]
Cryphonectria gyrosa [2]
Endothia havanensis [3]   No evidence that the above are economic pests.
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
4.07 No evidence  
4.08 (1) ' Young stands are moderately sensitive to fire damage, but in older trees their basal stocking of fibrous bark gives some protection from the effects of fire.'  (2))'Usually about half to two-thirds of the stumps will sprout. Age, weather, and (probably) heredity influence coppicing. The tree also usually produces a mass of special bud tissue at the groundline known as a lignotuber. The lignotuber will sprout if the stem is killed back by fire or other injury. [An evergreen tree - fibrous bark also makes the species less likely to carry fires]. (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
4.09  Saligna eucalyptus is classed as very intolerant of shade and the slower growing trees in a stand quickly become suppressed. http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
4.1  'It is a lignotuberous species of good coppicing ability and will tolerate a wide range of soil types from clays to sands.'   - Soil texture: light; medium; heavy
  - Soil drainage: free
  - Soil reaction: acid
  - Special soil tolerances:
  - Soil types: clay soils; podzols; volcanic soils
CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
4.11 No evidence  
4.12 No evidence  
5.01  'A medium to tall tree, usually 30-55 m in height with a dbh up to 2 m.' CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
5.02  'A medium to tall tree, usually 30-55 m in height with a dbh up to 2 m.' CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
5.03 No evidence. http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=EUSA
5.04  'A medium to tall tree, usually 30-55 m in height with a dbh up to 2 m.' CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
6.01  'In its natural habitat, E saligna usually bears heavy seed crops only every 2-3 years.' CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
6.02  'E. saligna is easily raised from seed in the nursery. ' CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
6.03 (1) 'Most current interest in the species in countries such as Brazil is as a parent in hybrid combinations that are adaptable and exhibit heterosis in growth. Seven hybrid combinations have been recognized as occurring in nature (Griffin et al., 1988), including the intergrade with E. botryoides (see Taxonomy and Nomenclature section). Interestingly, no natural hybrids have been recorded between E. saligna and E. grandis or produced by hand pollination (Eldridge et al., 1993), although spontaneous hybrids have been reported from plantations in South Africa and Florida (Griffin et al., 1988). Spontaneous hybrids with E. urophylla have occurred in Brazil (Eldridge et al., 1993). One of the best known artificial hybrid combinations involving E. saligna is Eucalyptus 12ABL (E. tereticornis) P E. saligna which is propagated clonally and used in pulp- and fuel-wood plantations in the Congo (Hamel and Laclau, 1996). Eucalyptus saligna P E. tereticornis clones have been screened for frost tolerance in Florida, USA (Meskimen et al., 1987). '  (2) 'Before 1918, many introductions were made worldwide of seed collected from "E. saligna" that bore the characteristics of the type later to be called E. grandis. In most countries where introductions were made, therefore, considerable mixed planting and hybridization of the two species are present. Thus, in Hawaii, most saligna eucalyptus stands contain trees with a range of characteristics intermediate between those of E. saligna and E. grandis.'    (3)In addition to the Eucalyptus grandis/E. saligna complex, E. saligna crosses with E. robusta, bangalay eucalyptus (E. botryoides), and probably with forest redgum eucalyptus (E. tereticornis) (12,28). In the southern part of its natural range, a region of introgression of E. saligna with E. botryoides exists (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.                                                             (2) and (3)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
6.04 (1) 'Eucalypts have hermaphrodite, protandrous flowers and are pollinated by insects or birds (Griffin, 1989). They reproduce by a mixed mating system, with both outcrossing and selfing (Moran and Bell, 1983; Moran, 1992). The outcrossing rate of E. saligna as estimated from allozyme analysis was 77%.'  (2)Pollen is generally shed before the style becomes receptive, so selfing is rare. (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
6.05   The opened flowers are yellowish white and are insect pollinated. http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
6.06 No evidence regarding vegetative spread in the wild.  
6.07  'Saligna eucalyptus trees begin to flower at 3 to 4 years of age.' http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
7.01 Although the species makes a fine avenue tree (1), no evidence that it grows in heavilty trafficked areas. CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
7.02  'E. saligna is a reasonably fast-growing hardwood species that gives a wood suitable for use in general construction, joinery, decking, decorative flooring, paneling, reconstituted wood products and pulpwood.' … 'Eucalyptus saligna is used in shelterbelts and makes a fine avenue tree.' CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
7.03 Probably not - no evidence that the species grows in proximity to produce plants. CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
7.04  'Seeds are naturally dispersed by wind.' http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
7.05    
7.06  'The fruit are woody capsules, shortly stalked or almost sessile, obconical to slightly pyriform, to 8 P 7 mm; valves 3 or 4, erect with thin pointed tips, either just protruding above the rim level or strongly exserted, usually conspicuously outcurved; seed brown.'  [Probably not - fruit is a woody capsule]. CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.
7.07 No evidence that the propagules have any means of attachment. http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
7.08 No evidence of ingestion.  
8.01 (1) 'Seeds are black, irregularly shaped, and about 1.3 mm (0.05 in) in diameter. They are released along with a large amount of reddish-brown chaff when the capsule valves open. There are 460 viable seeds per gram (13,000/oz) of seed plus chaff (20).'  (2)Seeds many, tiny, 1–2 mm long, dull light brown. [Yes- because relatively small seeds]. (1)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm  (2)http://www.hort.purdue.edu/newcrop/duke_energy/Eucalyptus_saligna.html#Uses
8.02 (1)'Viability of seed stored dry (5-8% moisture content) in airtight containers in the refrigerator (3-5C) will be maintained for several years. No pre-sowing treatment is required.'  (2)Fresh seeds germinate readily in 10 to 20 days without pregermination treatment. Seeds can be stored in airtight containers for several years at 0 to 5 C (32 to 41 F) (20).[No evidence of seed viability under natural conditions]. (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
8.03 Don’t know. No evidence that the species is being controlled for.  
8.04 (1) ' Young stands are moderately sensitive to fire damage, but in older trees their basal stocking of fibrous bark gives some protection from the effects of fire.'  (2)'Usually about half to two-thirds of the stumps will sprout. Age, weather, and (probably) heredity influence coppicing. The tree also usually produces a mass of special bud tissue at the groundline known as a lignotuber. The lignotuber will sprout if the stem is killed back by fire or other injury. ... Saligna eucalyptus can sprout prolifically from dormant buds located in the cambium throughout the stem. After a tree is cut, shoots sprout from many points on the remaining bark surface.' (1)CAB International, 2000. Forestry Compendium Global Module. Wallingford, UK: CAB International.  (2)http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/eucalyptus/saligna.htm
8.05 Don’t know.  

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