Statement of Intent to Declare Ilex aquifolium

STATEMENT OF INTENT TO DECLARE

Scientific Name:     Ilex aquifolium

Common Name/s:  holly

Interpretation:

In this statement -
  • "holly" means Ilex aquifolium
  •  Schedules attached:

            none


Reasons for making the order

Ilex aquifolium (holly) comes from a genus of over 400 species (Heywood 2007). It originates from West Asia, North Africa, and South and West Europe (Kew Royal Botanic Gardens 2016). Many species of the Ilex genus are recorded to have become weedy and/or naturalised (outside their natural range), somewhere in the world. However, Ilex aquifolium appears to be the most widely distributed as a weed (Randall 2012).

West Coast Council nominated holly for declaration in order to assist them with managing holly infestations in their municipality. However, herbarium records indicate that holly is naturalised across much of Tasmania, and several other Tasmanian municipalities list holly prominently in their environmental weed priorities (Queensland Government 2016).

The impacts of holly are primarily environmental. It is invasive in forests and woodlands in Australia (particularly Tasmania and Victoria), New Zealand, and Hawaii and the western United States of America (Muyt 2001, DiTomaso and Healy 2007, Popay et al 2010). In Tasmania it is of particular concern where it out-competes and replaces indigenous species in riparian and wet forest situations. Holly forms dense thickets and creates deep shade that prevents growth of native species. Social impacts of holly are primarily that the fruit and leaves are toxic (reported to cause serious digestive tract problems when ingested by children - DiTomaso and Healy 2007, Queensland Government 2016). In agricultural situations holly invades pasture and grows on fence lines (creating fence maintenance and replacement difficulties).

Holly is proposed for declaration in Tasmania because it is invasive on public and private Tasmanian lands, and regulation is potentially part of managing this issue. It also continues to be promoted as a garden ornamental and regulation can help prevent ongoing distribution and planting of the species.


Restrictions or measures proposed in respect of the weed

Except with the written approval of the Secretary, a person must not import or allow to be imported into the State any holly.

The tolerance level for holly seed in imported grain will be 0 seeds per kilogram

Land owners and managers shall take all reasonable measures to control the impact and spread of holly. A person must not propagate, trade or otherwise distribute holly or anything carrying holly except:

  1. transport for purposes of disposal
  2. sale or transport for purposes other than disposal where authorised by the Secretary

Holly plants shall be disposed of in a manner which will not result in further infestation.


Any other relevant matters


Weed Risk Assessment

Assessment conducted 2016

by   Michael Noble (Coordinator – Risk Assessment and Review)


Results

A quantitatively based weed risk assessment was undertaken for holly recommending that the plant poses a significant risk and supporting its declaration.  The biogeographical attributes of holly (currently naturalised in parts of Australia; climatically suited to Tasmania; known environmental weed) scored the majority of points in the weed risk analysis.  Biological and ecological attributes were a minor contributor to the overall score.  The weed risk analysis scored the environment higher than agriculture as the sector most likely to be affected.


References

DiTomaso, J.M. and Healy, E.A. (2007). 'Weeds of California and other western states – Volume 1'. (University of California, Oakland, California).

Heywood, V.H., Brummitt, R.K., Culham, A., and Seberg, O. (2007). Flowering plant families of the world. Firefly Books Ltd., Buffalo, New York, USA.

Kew Royal Botanic Gardens (2016). Ilex aquafolium (common holly). http://www.kew.org/science-conservation/plants-fungi/ilex-aquifolium-common-holly (accessed 17 February 2016).

Popay, I., Champion, P. and James, T. (2010). An illustrated guide to common weeds of New Zealand (3rd ed.). New Zealand Plant Protection Society, Christchurch.

Queensland Government (2016).Holly Ilex aquifolium. http://keyserver.lucidcentral.org/weeds/data/media/Html/ilex_aquifolium.htm (accessed 22 June 2016).

Randall, R.P. 2012. A global compendium of weeds (2nd Ed.). Department of Agriculture and Food, Western Australia. http://www.cabi.org/cabdirect/FullTextPDF/2013/20133109119.pdf (accessed 6 February 2015).

For further information:

Contact

Michael Noble
Biosecurity Tasmania
Phone: (03) 6421 5100
Email: Michael.Noble@dpipwe.tas.gov.au

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