Cork oak (Quercus suber)

Present distribution

Scientific name:	Quercus suber L.
Common name(s):	cork oak

Map showing the present distribution of this weed.

Habitat:

On schistic, granitic and silt-loam soils. “The deep root system probably contributes to this by keeping the water potential at a high level even during the summer period” (Oliveira 1992). “Evergreen tree with sclerophyllous leaves which grows in carbonate-free soils. It constitutes forests or open wood-lands where it is the main tree species” (Pausas 1997). Distributed in marsh-scrub ecotone or scattered over stabilised dunes, usually near
ephemeral ponds. Also growing at the transition from heath to xerophytic scrub (Herrera 1995). “Confined to non-calcareous formations…From almost sea level to 4,500 feet, slopes are steep; it does not grow on flat gully bottom country…will not grow on limestone [or] even light clays. [Occurs in] small areas on the coast region of Algeria…Cork oak is extremely intolerant of shade…Good growth is obtained only when the taproot is able to
penetrate easily, for this reason heavy clay soils or waterlogged subsoils are inimical to its growth” (Byles 1931). “Prefers medium (loamy) and heavy (clay) soils” (PFAF 1996-2008).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:
Broadacre cropping; horticulture perennial; pasture dryland; pasture irrigation

Ecological Vegetation Divisions
Coastal; heathland; grassy/heathy dry forest; swampy scrub; treed swampy wetland; lowland forest; foothills forest; forby forest; granitic hillslopes; rocky outcrop shrubland; western plains woodland; basalt grassland

Colours indicate possibility of Quercus suber infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

map of the potential distribution of quercus suber

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	“Growing to 20 m by 15 m” (PFAF 1996-2008). Due to its size, it may become a major impediment to access waterways or machinery. Significant works could be required to provide reasonable access, tracks closed or impassable.	H	ML
2. Reduce tourism?	“Growing to 20 m by 15 m” (PFAF 1996-2008). Due to its size, some recreational uses may be affected.	MH	ML
3. Injurious to people?	“Poisoning in children from chewing a few acorns need cause little worry before in the introduction the potato, acorns were a (starch-containing) food in times of emergency” (Pfander 1984). “Leaves are alternate, simple and leathery, with spiny, serrate margins” (Bodkin 1986). Not toxic to people but may cause some physiological issues from spiny, serrated leaf margins.	ML	ML
4. Damage to cultural sites?	“The taproot is well developed and penetrates to a great depth, but the main rooting system is made up of laterals” (Byles 1931). May cause a moderate structural effect.	MH	ML
Abiotic
5. Impact flow?	“Occupying…areas on schistic and granitic soils”. Also on silt-loam soil (Oliveira 1992). “Distributed either in the marsh-scrub ecotone or are scattered over the stabilised dunes, usually near ephemeral ponds. [Also] growing at the transition from heath to xerophytic scrub” (Herrera 1995). “Confined to non-calcareous formations…Good growth is obtained only when the taproot is able to penetrate easily, for this reason heavy clay soils or waterlogged subsoils are inimical to its growth” (Byles 1931). Not known to be aquatic. Negligible affect on water flow.	L	M
6. Impact water quality?	“Occupying…areas on schistic and granitic soils”. Also on silt-loam soil (Oliveira 1992). “Distributed either in the marsh-scrub ecotone or are scattered over the stabilised dunes, usually near ephemeral ponds. [Also] growing at the transition from heath to xerophytic scrub” (Herrera 1995). “Confined to non-calcareous formations…Good growth is obtained only when the taproot is able to penetrate easily, for this reason heavy clay soils or waterlogged subsoils are inimical to its growth” (Byles 1931). Not known to be aquatic. Negligible affect on water flow.	L	M
7. Increase soil erosion?	“The taproot is well developed and penetrates to a great depth, but the main rooting system is made up of laterals” (Byles 1931). Probably decreases the probability of soil erosion.	L	ML
8. Reduce biomass?	“Cork oak is extremely intolerant of shade” (Byles 1931). “Distributed either in the marsh-scrub ecotone or are scattered over the stabilised dunes, usually near ephemeral ponds. [Also] growing at the transition from heath to xerophytic scrub” (Herrera 1995). Could invade areas that has lower vegetation such as marsh or heath, therefore, biomass may increase.	L	ML
9. Change fire regime?	“Very fire resistant” (Byles 1931). “Plant materials, while it may accentuate the damage caused by fire, can also be used to slow or divert the fire…Deciduous hardwoods that are suitable include oaks (Quercus spp.)” (Cremer 1990). Could greatly change the frequency and/ or intensity of fire.	H	ML
Community Habitat
10. Impact on composition (a) high value EVC	EVC = Grassy Woodland (E); CMA =Corangamite; Bioregion =Victorian Volcanic Plains; VH CLIMATE potential. “It constitutes forests or open wood-lands where it is the main tree species” (Pausas 1997). May cause major displacement of some dominant spp. within a strata/layer (or some dominant spp. within different layers.	MH	M
(b) medium value EVC	EVC = Herb-rich Foothill Forest (D); CMA = Goulburn Broken; Bioregion = Central Victorian Uplands; VH CLIMATE potential. “It constitutes forests or open wood-lands where it is the main tree species” (Pausas 1997). May cause major displacement of some dominant spp. within a strata/layer (or some dominant spp. within different layers.	MH	M
(c) low value EVC	EVC = Shrubby Dry Forest (LC); CMA = East Gippsland; Bioregion = East Gippsland Uplands; VH CLIMATE potential. “It constitutes forests or open wood-lands where it is the main tree species” (Pausas 1997). May cause major displacement of some dominant spp. within a strata/layer (or some dominant spp. within different layers.	MH	M
11. Impact on structure?	“It constitutes forests or open wood-lands where it is the main tree species” (Pausas 1997). Minor effect on >60% of the layers or major effect on <60% of the flora strata.	MH	M
12. Effect on threatened flora?	No information found directly referring to threatened fauna.	MH	L
Fauna
13. Effect on threatened fauna?	No information found directly referring to threatened flora.	MH	L
14. Effect on non-threatened fauna?	Not enough information.	M	L
15. Benefits fauna?	“In Spain, acorns [of Quercus ilex] are consumed by many species of birds and mammals…The main mammalian predators in the Lerma region are Wild Board, Sus scrofa, and Wood Mice, Apodemus sylvaticus, While Tits, Chaffinces, Wood Pigeons, Robins, Nuthatches, and Jays are potentially the main avian predators” (Santos and Telleria 1997). “In most years it is normal for animals, particularly horses to eat acorns as a highly nutritious pre-winter feed, sever poisoning may occur…Pigs have been poisoned by excessive quantities of acorns, but such an occurrence is very rare, These animals usually thrive on them (Cooper and Johnson 1984). Could provide some assistance in either food or shelter to desirable species.	MH	ML
16. Injurious to fauna?	“Several species are known to be toxic; Kingsbury suggests that all should be regarded as potentially toxic…Experimental feeding of fresh, frozen, or dried blossoms, buds, leaves, and twigs of Q. havardii caused disease in cattle, sheep, goats, rabbits, and guinea pigs” (Keeler et al. 1978). Poisoning can occur in horses, cattle, sheep and pigs (Cooper and Johnson 1984). “Leaves, young shoots, buds and acorns are poisonous and with a bitter taste; also allergenic. Can be toxic to domestic pets. Also toxic to livestock. Toxins Tannins. (Shepherd 2004). Toxic, and causes allergies.	H	ML
Pest Animal
17. Food source to pests?	Seeds were eaten “by a variety of vertebrate herbivores (cattle, red deer, fallow deer, wild boar and rabbits)…One of these trees…was consistently used as a seed source because its acorns were abundant (the year’s crop was estimated at 10 [to the power of] 4 acorns)” (Herrera 1995). Supplies food for >1 major pest species at crucial times of the year (e.g. heavy berry load or continual food throughout the year).	H	MH
18. Provides harbour?	“Growing to 20 m by 15 m” (PFAF 1996-2008). “Q. suber is an evergreen tree” (Pausas 1997). Doesn’t provide harbour for serious pest species, but may provide for minor pest species.	ML	ML
Agriculture
19. Impact yield?	“Oak poisoning in cattle occurs in many parts of the world and is of major economic importance in some places…Death may occur suddenly during a convulsion…Eight sheep died after grazing young oak shoots” Poisoning can occur in horses, cattle, sheep and pigs (Cooper and Johnson 1984). “Several species are known to be toxic; Kingsbury suggests that all should be regarded as potentially toxic…Experimental feeding of fresh, frozen, or dried blossoms, buds, leaves, and twigs of Q. havardii caused disease in cattle, sheep, goats, rabbits, and guinea pigs” (Keeler et al. 1978). Could be a major impact on quantity of produce (e.g. 5-20%).	MH	M
20. Impact quality?	“Oak poisoning in cattle occurs in many parts of the world and is of major economic importance in some places…The milk from lactating animals is often bitter and unusable for any purpose” (Cooper and Johnson 1984). Serious impacts on quality. Produce rejected for sale or export.	H	M
21. Affect land value?	Not enough information.	M	L
22. Change land use?	“Quercus suber (Cork oak) tree [has] a life expectation ranging from 200-500 years” (Ponte e Saous et al. 2003). Not likely to change land use as it is a slow growing plant and the impacts of its presence could be minimised.	L	ML
23. Increase harvest costs?	“Oak poisoning in cattle occurs in many parts of the world and is of major economic importance in some places…The milk from lactating animals is often bitter and unusable for any purpose” (Cooper and Johnson 1984). Slightly more time and labour may be required to remove acorns, seedlings, etc. to prevent contamination. Minor increase in cost of harvesting.	M	ML
24. Disease host/vector?	“Chestnut blight: Cryphonectria parasitica (Murr.) Barr. …Hosts: chestnut, oak …Entire trees may die if the trunk is girdled. Likely pathway: nuts/seeds, nursery stock, bark, lumber and wood packaging material including. Potential impact: one of the most serious plant diseases in North America. Within 50 years the disease spread to the extremes of the natural range of the American chestnut, destroying the economic and aesthetic value of one of America’s most versatile trees. (Agriculture, Fisheries and Forestry- Australia 2001). Host to major and severe disease or pest of important agricultural produce.	H	M

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	“Before germination acorns were soaked for 48 h at 20°C and sterilised by washing in 80% sodium chloride solution. The pericarp was then removed and acorns were cut-off one-third at scar end and placed to germinate in the dark at 20°C, in moist heat-sterilised sand” (Branco et al. 2002). Possibly only requires natural seasonal disturbances such as seasonal rainfall, spring/summer temperatures for germination.	MH	ML
2. Establishment requirements?	Cork oak is extremely intolerant of shade” (Byles 1931). Requires more specific requirements to establish (e.g. open space or bare ground with access to direct light).	ML	M
3. How much disturbance is required?	“Growing at the transition from heath to xerophytic scrub” (Herrera 1995). Establishes in healthy and undisturbed natural ecosystems (e.g. heathland).	H	M
Growth/Competitive
4. Life form?	“Q. suber is an evergreen tree” (Pausas 1997). Other.	L	H
5. Allelopathic properties?	“The mulch of the leaves repels slugs, grubs etc, though fresh leaves should not be used as these can inhibit plant growth” (PFAF 1996-2008). May seriously affect some plants.	MH	ML
6. Tolerates herb pressure?	“Seedlings killed or eaten back sprout again from the crown” (Byles 1931). “Trees that re-sprout from stem buds [including] Quercus suber” (Pausas 1999). “Holm Oak is capable of both sexual and vegetative regeneration, so propagation might mainly occur by vegetative sprouting in patches with heavy acorn predation” (Santos & Telleria 1997). May have similar predation to Holm oak. Consumed and recovers slowly. Reproduction strongly inhibited by herbivore, but still capable of vegetative propagule production (by rhizomes or tubers); weed may still persist.	ML	M
7. Normal growth rate?	“Several of the cool-temperate species grow more quickly in the relatively warm SE Australian climate” (Spencer 1995). Maximum growth rate less than many species of the same life form.	ML	ML
8. Stress tolerance to frost, drought, w/logg, sal. etc?	“Fire burnt both the understorey and the crowns, and all pines were killed…while Q. suber trees were re-sprouting from the base and from the canopy” (Pausas 1997). “Very fire resistant…Good growth is obtained only when the taproot is able to penetrate easily, for this reason heavy clay soils or waterlogged subsoils are inimical to its growth” (Byles 1931). “Drought and frost resistant” (Bodkin 1986). “Drought resistant” (Oliveira 1992). Highly resistant to fire. Highly tolerant of drought and frost. Susceptible to water-logging.	MH	M
Reproduction
9. Reproductive system	“Trees that re-sprout from stem buds [including] Quercus suber” (Pausas 1999). “One of these trees…was consistently used as a seed source because its acorns were abundant (the year’s crop was estimated at 10 [to the power of] 4 acorns)” (Herrera 1995). Both vegetative and sexual reproduction.	H	MH
10. Number of propagules produced?	“One of these trees…was consistently used as a seed source because its acorns were abundant (the year’s crop was estimated at 10 [to the power of] 4 acorns)” (Herrera 1995). 10 to the power of 4=10,000 acorns produced.	H	M
11. Propagule longevity?	“Seed- it quickly loses viability if it is allowed to dry out. It can be stored moist and cool overwinter” (PFAF 1996-2008). Seeds were eaten “by a variety of vertebrate herbivores (cattle, red deer, fallow deer, wild boar and rabbits)” (Herrera 1995). “Holm Oak is capable of both sexual and vegetative regeneration, so propagation might mainly occur by vegetative sprouting in patches with heavy acorn predation” (Santos & Telleria 1997). “Trees that re-sprout from stem buds [including] Quercus suber” (Pausas 1999). May have similar predation to Holm oak. Unlikely to have a high viability rate or more than 25% of seeds surviving 5 years, though does reproduce vegetatively.	L	ML
12. Reproductive period?	“Quercus suber (Cork oak) tree [has] a life expectation ranging from 200-500 years” (Ponte e Saous et al. 2003). Likely to produce viable propagules for 10 years or more as it lives for so long.	H	ML
13. Time to reproductive maturity?	No information found.	M	L
Dispersal
14. Number of mechanisms?	“Vertebrates which cache seeds such as birds and mammals are often effective dispersal agents” (Herrera 1995). Bird dispersed seeds and has edible fruit that is readily eaten by highly mobile animals.	H	M
15. How far do they disperse?	“Vertebrates which cache seeds such as birds and mammals are often effective dispersal agents” (Herrera 1995). Potentially very likely that at least one propagule will disperse greater than one kilometre.	H	ML

References

Agricultural, Fisheries and Forestry - Australia. (2001) Forests and Timber: A Field Guide to Exotic Pests and Diseases. Australian Quarantine and Inspection Service, the National Office of Animal and Plant Health, and the Ministerial Council on Forestry, Fisheries and Aquaculture - Standing Committee on Forestry, Canberra.

Bodkin F. (1986) Encyclopaedia Botanica: The Essential Reference Guide to Native and Exotic Plants in Australia. Angus & Robertson.

Branco M, Branco C, Merouani H, Almeida M (2002) Germination success, survival and seedling vigour of Quercus suber acorns in relation to insect damage. Forestry Ecology and Management. 166: 159-164.

Byles (1931) Report on Cork. Commonwealth Government Printer, Canberra.

Cooper MR and Johnson AW. (1984) Poisonous Plants in Britain and their Effects on Animals and Man. Ministry of Agriculture, Fisheries and Food. Her Majesty’s Stationary Office, London.

Cremer K.W. (1990) Trees for Rural Australia. Inkata Press Pty. Ltd. Melbourne, Sydney.

Herrera J. (1995) Acorn predation and seedling production in low-density population of cork oak (Quercus suber L.). Forest Ecology and Management. 76: 197-201.

Keeler R.F, Van Dampen K.R, and Jampes L.F. (1978). Effects of Poisonous Plants on Livestock. Academic Press, New York.

Oliveira G, Correia O.A, Martins-Loucao M.A, and Catarino F.M. (1992) Water relations of cork-oak (Quercus suber L.) under natural conditions. Vegetatio. 99-100:199-208.

Pausas J.G. (1997) Resprouting of Quercus suber in NE Spain after fire. Journal of Vegetation Science. 8:703-706.

Pausas J.G. (1999) Mediterranean vegetation dynamics: modelling problems and functional types. Plant Ecology. 140: 27-39.

Pfander F. (1984) A Colour Atlas of Poisonous Plants: A Handbook for Pharmacists, Doctors, Toxicologists and Biologists. Wolfe Publishing Ltd, London.

Plants for a Future. (PFAF) (1996-2008) Edible, Medicinal and Useful Plants for a Healthier World. Available at: http://pfaf.org/ (verified 09/09/2009).

Ponte e Sousa J, Teixeira J.M.G and Vaz A.M.N. (2003) The Importance of he Cork (Bark) of Quercus suber in the Environmental Monitoring of Heavy Metals. Electronic Journal of Environmental, Agricultural and Food Chemistry. 2, (2), 314-319. Also Available at: http://ejeafche.uvigo.es/index.php?option=com_docman&task=doc_view&gid=180

Pulido F.J, Diaz M, Hidalgo de Trucios S.J. (2001) Size structure and regeneration of Spanish holm oak Quercus ilex forests and dehesas: effects of agroforestry use on their longterm sustainability. Forest Ecology and Management. 146: 1-13.

Santos T. and Telleria J.L. (1997) Vertebrate predation on Holm oak, Quercus ilex, acorns in a fragmented habitat: effects on seedling recruitment. Forest Ecology and Management. 98: 181-187.

Shepherd RCH. (2004) Pretty But Poisonous. Plants Poisonous to People, An Illustrated Guide for Australia. RG & FJ Richardson. Meredith, Australia.

Spencer R. (Ed.) (1997) Horticultural Flora of South-Eastern Australia Volume 2. Flowering Plants Dicotyledons Part 1. UNSW Press.

Global present distribution data references

Australian National Herbarium (ANH) (2009) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, Available at http://www.anbg.gov.au/avh/ (verified 01/09/2009).

Department of Sustainability and Environment (DSE) (2006) Flora information system [CD-ROM], Biodiversity and Natural Resources Section, Viridans Pty Ltd, Bentleigh.

Global Biodiversity Information Facility (GBIF) (2008) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 29/06/2009).

Integrated Taxonomic Information System. (2009) Available at http://www.itis.gov/ (verified 29/06/2009).

Missouri Botanical Gardens (MBG) (2009) w³TROPICOS, Missouri Botanical Gardens Database, Available at http://mobot.mobot.org/W3T/Search/vast.html (verified 29/06/2009).

Royal Botanic Gardens Melbourne. (2003) Census of Vascular Plants of Victoria. Available at http://www.rbg.vic.gov.au/research_and_conservation/plant_information/viclist (verified 29/06/2009).

United States Department of Agriculture. Agricultural Research Service, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. Taxonomy Query. (2009) Available at http://www.ars-grin.gov/cgi-bin/npgs/html/taxgenform.pl (verified 29/06/2009).

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