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
Pacific Island Ecosystems at Risk (PIER)
Allocasuarina verticillata
RISK ASSESSMENT RESULTS: Low risk, score: -5
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Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i. Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service Information on
Risk Assessments |
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Allocasuarina verticillata (Casuarina stricta, Casuarina verticillata); Drooping She Oak |
Answer |
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|
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 |
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 |
|
|
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 |
n |
|
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 |
n |
|
4.08 |
Creates a fire hazard in natural ecosystems |
y=1, n=0 |
|
|
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 |
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 |
n |
|
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 |
n |
|
6.07 |
Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1 |
See left |
5 |
|
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 |
|
|
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 |
|
|
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 |
|
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Total score: |
-5 |
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Supporting data:
|
Source |
Notes |
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1.01 |
no evidence |
|
|
1.02 |
no evidence |
|
|
1.03 |
no evidence |
|
|
2.01 |
http://www.australiaplants.com/Allocasuarina_verticillata.htm |
Native South Australia, Victoria, New South Wales, Tasmania ; Temperature Rating: USDA Zone 9 |
|
2.02 |
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|
2.03 |
(1)http://www.australiaplants.com/Allocasuarina_verticillata.htm (2)http://www.gisparks.tas.gov.au/TASVEG2000/tasveg_units/AV.htm (3)http://www.gardenbed.com/C/4429.cfm (4)http://www.bushcare.tas.gov.au/info/sheoak.htm |
(1)Native South Australia, Victoria, New South Wales, Tasmania ; Temperature Rating: USDA Zone 9 , salt tolerant, lime tolerant, drought tolerant, Tolerates extreme conditions. (2)altitudes <500m and most commonly occurs near the coast, A. verticillata is more drought resistant than the eucalypts, and can form pure stands on the driest sites in Tasmania. As the soil moisture increases A. verticillata woodlands grade into Eucalyptus viminalis (white gum)/ A. verticillata woodlands. (3)Calcareous sands by the coast, inland on poor rocky soils and on sand overlying clay (4)in Australia dominates "shallow and rocky soils in areas receiving less than 700 mm of rainfall." [mainly a low elevation coastal species, dry environments] |
|
2.04 |
http://www.australiaplants.com/Allocasuarina_verticillata.htm |
Native South Australia, Victoria, New South Wales, Tasmania ; Temperature Rating: USDA Zone 9 |
|
2.05 |
(1) Weinstein, A. (1993) Provenance trials of Casuarina
cunninghamiana, Casuarina glauca, and Allocasuarina verticillata in Israel.
Australian Forestry, 1993, Vol.56, No.1, pp.34-37, 8 ref. |
(1) Israel, (2)France(3)A. verticillata has been used extensively on difficult sites both in Australia and abroad. [but cannot find specific examples] |
|
3.01 |
no evidence |
|
|
3.02 |
no evidence |
|
|
3.03 |
no evidence |
|
|
3.04 |
no evidence |
|
|
3.05 |
Allocasaurina is taxonomically distinct from the weedy species in the genus Casaurina |
|
|
4.01 |
http://www.australiaplants.com/Allocasuarina_verticillata.htm |
no description of these traits |
|
4.02 |
no evidence |
|
|
4.03 |
no evidence |
|
|
4.04 |
(1)Pepper, J. W. (1997) A survey of the South Australian glossy black-cockatoo (Calyptorhynchus lathami halmaturinus ) and its habitat. Wildlife Research, 1997, Vol.24, No.2, pp.209-223, 31 ref. (2)http://pln.netc.net.au/parklanenursery/plantids.html (3)http://www.bushcare.tas.gov.au/info/sheoak.htm |
(1)Grazing by sheep in much of the habitat reduced but did not prevent sheoak regeneration. (2)fodder for cattle (3)under light grazing regimes eucalypts may re-establish successfully but not she-oaks. |
|
4.05 |
no evidence |
|
|
4.06 |
no evidence |
|
|
4.07 |
no evidence |
|
|
4.08 |
(1)http://farrer.riv.csu.edu.au/ASGAP/fire.html (2)http://www.gisparks.tas.gov.au/TASVEG2000/tasveg_units/AV.htm |
(1)suggested to be planted in fire prone area to prevent fire (2)can form "an almost closed forest with little else but needles beneath the trees" [suggests flammable understory] |
|
4.09 |
(1)http://www.australiaplants.com/Allocasuarina_verticillata.htm (2)http://www.gardenbed.com/C/4429.cfm (3)http://www.bushcare.tas.gov.au/info/sheoak.htm |
(1)"Culture: Full sun to part shade" (2)full sun (3)it can also form a major understorey component of eucalypt forest. |
|
4.1 |
(1)http://www.australiaplants.com/Allocasuarina_verticillata.htm (2)http://www.gardenbed.com/C/4429.cfm |
(1)Culture: Sand, loam or clay, well drained to dry soils. Acid, neutral or alkaline. Frost tolerant. (2)Often found in poor dry soils in the wild |
|
4.11 |
tree |
|
|
4.12 |
(1)http://www.backyardorganicgardening.com/native/sheoak.html (2)http://www.bushcare.tas.gov.au/info/sheoak.htm |
(1)Today's blanketing She-oak woodland is a response to a change from the traditional aboriginal fire regime for the area (2)She-oak woodland and forest varies from an almost closed forest that has little else beneath the trees but needles [implies formation of dense stands in the absence of hot fire] |
|
5.01 |
terrestrial |
|
|
5.02 |
tree; Casuarinaceae |
|
|
5.03 |
Phelep, M.; Petit, A.; Martin, L.; Duhoux, E.; Tempé, J. (1991) Transformation and regeneration of a nitrogen-fixing tree, Allocasuarina verticillata Lam. Bio/Technology, 1991, Vol.9, No.5, pp.461-466, 34 ref. |
"a nitrogen-fixing tree" |
|
5.04 |
tree |
|
|
6.01 |
no evidence |
|
|
6.02 |
Moncur, M. W.; Boland, D. J.; Harbard, J. L. (1997) Aspects of the floral biology of Allocasuarina verticillata (Casuarinaceae). Australian Journal of Botany, 1997, Vol.45, No.5, pp.857-869, 22 ref. |
"Seed germinated well at temperatures between 10 deg C and 25 deg C but there was a marked decline at 30 deg C. Stratification of seed is suggested as a standard practice in germination tests." |
|
6.03 |
no evidence [this group has been thoroughly studied, but no record of hybrids] |
|
|
6.04 |
Moncur, M. W.; Boland, D. J.; Harbard, J. L. (1997) Aspects of the floral biology of Allocasuarina verticillata (Casuarinaceae). Australian Journal of Botany, 1997, Vol.45, No.5, pp.857-869, 22 ref. |
" The trees are dioecious" |
|
6.05 |
http://www.backyardorganicgardening.com/native/sheoak.html |
The female's flowers are designed to hang well out to catch the wind born pollen grains that wafts pass from the nearby male. The production of pollen can be so prolific that they often produce a reddish carpet of pollen under the trees. |
|
6.06 |
no evidence |
|
|
6.07 |
http://www.backyardorganicgardening.com/native/sheoak.html |
young She-oaks need to have at least 5 to 7 years of growth before they start to produce seed bearing cones and at least 10 years before they have a reasonable number of cones in their canopy. |
|
7.01 |
no evidence |
|
|
7.02 |
a forestry and ornamental species |
|
|
7.03 |
no evidence |
|
|
7.04 |
no evidence |
|
|
7.05 |
no evidence |
|
|
7.06 |
Pepper, J. W.; Male, T. D.; Roberts, G. E. (2000) Foraging ecology of the South Australian glossy black-cockatoo (Calyptorhynchus lathami halmaturinus ). Austral Ecology, 2000, Vol.25, No.1, pp.16-24, 21 ref. |
AB: "The endangered South Australian glossy black-cockatoo feeds almost exclusively on the seeds of the drooping sheoak (Allocasuarina verticillata ), and shows marked preferences for individual trees." [a seed predator but may disperse seed by dropping cones with seeds left ] |
|
7.07 |
no means of attachment |
|
|
7.08 |
no evidence |
|
|
8.01 |
seem to have large number of seeds in each cone |
|
|
8.02 |
http://www.backyardorganicgardening.com/native/sheoak.html |
the seed are stored in the cones within its canopy (where it maybe stored for up to 10 years). These will only stay viable for less than 3 months in the soil. [can be effectively removed when trees are removed, so not persistent] |
|
8.03 |
no evidence |
|
|
8.04 |
(1)Pepper, J. W. (1997) A survey of the South Australian glossy black-cockatoo (Calyptorhynchus lathami halmaturinus ) and its habitat. Wildlife Research, 1997, Vol.24, No.2, pp.209-223, 31 ref. (2)http://www.backyardorganicgardening.com/native/sheoak.html |
(1)"The fire killed most sheoaks but not most eucalypts (Eucalyptus spp., found both as overstorey trees in some sheoak woodland and elsewhere); burned sheoak woodland was regenerating from both seedlings and basal shoots. " (2)they will re-sprout from their bases |
|
8.05 |
no evidence |
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