Literature review: Impact of Chilean needle grass ... - Weeds Australia

and high impact (“ability to cause actute disruption to ecological processes, dominae vegetation strata, cause severe loss of
biodiversity”), with a “moderate” area that could be occupied in a “low” range of habitat types (Platt et al. 2005).
Noxious weed status
The noxious weed status of N. neesiana in Australia States and Territories has developed as follows:
ACT: Declared Pest Plant under the Land (Planning and Environment) Act 1991 (Bruce 2001, ACT Weeds Working Group
2002), then from 12 November 2005 the Pest Plants and Animals Act 2005 (Australian Weeds Committe 2007). It is classified as
a C3/C4 pest plant: control is required (Glanznig and Kessal 2004), infestations must be contained and propagation and supply is
prohibited.
Victoria: First declared noxious on 27 October 2005, as a Restricted Weed under the Catchment and Land Protection Act 1994
(Anon. 2005). It is an offence to trade and transport the plant and to deposit it on land, but there is no legal requirement for
landowners to control infestations on their land. Listed as a high priority ‘New and Emerging Weed’ in the North Central Region
Weed Action Plan 2001-2005 (Frederick 2002) and as a ‘Priority weed’ in the Regional Weed Action Plans for Port Phillip,
North East, Goulburn-Broken, North Central, Wimmera,Corangamite andGlenelg-Hopkins regions (McLaren et al. 2002b).
New South Wales: Declared noxious in 11 local government areas (Benson and McDougall 2005). In 2004 regional control and
declaration was applied under the Noxious Weeds Act 1993,with prohibition of trade and eradication or control required
(Glanznig and Kessal 2004). Declared a weed statewide in 2006 (Iaconis 2006a) and listed as a Class 3 (Regionally Controlled)
weed for 25 Local Control Authority (LCA) areas and a Class 4 (Locally Controlled) weed for 103 LCA areas as of March 2007
(Australian Weeds Committee 2007). According to Snell et al. (2007) it is Class 3 species in 30 LCA areas and a Class 4 species
in all other areas. Both Classes cover weeds considered to be a serious threat to agriculture of the environment in the area. Class
3 weeds are not, and Class 4 weeds are widely distributed in the area in which they are declared. Declarations of a Class 3 weed
must include a minimum of three adjoining LCAs. LCAs may be either a local municipal government or a special purpose
county council. N. neesiana is not prohibited from trade since Class 3 and 4 weeds are not “notifiable” (Australian Weeds
Committee 2007).
Tasmania: Under the Weed Management Act 1999, as of June 2004, prohibited in trade, prohibited import and control required
(Glanznig and Kessal 2004). It is a declared plant under the Act and the details on actual restrictions imposed are contained in the
weed management plan (Australian Weeds Committee 2007). These include prohibitions of the importation of seed, the
importation of contaminated livestock, sale and distribution of the plant and measures to manage infestations and quarantine
items contaminated with seed (DPIW 2007). Importation is also restricted under the Plant Quarantine Act 1997 (DPIW 2007).
South Australia: Proclaimed under the former Animal and Plant Control (Agricultural Protection and Other Purposes) Act
1986 for control in the whole State in 2001, and after repeal of that Act declared under matching sections of the Natural
Resource Management Act 2004 (Iaconis 2006a). A Class 2 weed, requiring to notification by land owners to the relevant
authority and control throughout the State (Australian Weeds Committee 2007). Prohibited in trade, prohibited import (Glanznig
and Kessal 2004).
Queensland: Under the Land Protection (Pest and Stock Route Management) Act 2002, as of 2004, prohibited in trade and for
importation, eradication required (Glanznig and Kessal 2004). Declared a Class 1 weed throughout the State in 2005 (Iaconis
2006b). Class 1 weeds are not commonly present in the State are prohibited in trade, and where established are subject to
eradication (Australian Weeds Committee 2007).
Western Australia: Classed as ‘unassesed’: not risk-assessed under Western Australian protocols, so not included in the
‘Permitted and Prohibited List’ under the Plant Diseases Act 1989, but recognised as a declared pest plant in other States and
therefore prohibited from importation (Glanznig and Kessal 2004, Australian Weeds Committee 2007). According to Snell et al.
(2007) prohibited under Plant Diseases Act and listed as a P1 plant under the Agricultural and Related Resources Protection Act
1976 which prohibits movement and trade in the species.
Northern Territory: Under the Weeds Management Act 2001 not declared as of June 2004 (Glanznig and Kessal 2004), but
declared by March 2007 as a Class A and Class C noxious weed under the Weed Management Act 2001: “to be eradicated”,
prohibited from sale, and prohibited from introduction to the Territory (Australian Weeds Committee 2007, Snell et al. 2007).
Undesirable characteristics
In its introduced range including south-western Europe (Verloove 2005), New Zealand and Australia, N. neesiana forms dense
stands in invaded vegetation, including bushland and parkland (Liebert1996), and in pastures, where it can form canopy cover of
up to 60% (Gardener et al. 2003a). N. neesiana possesses many environmental traits that allow it to outcompete native
vegetation (Gardener and Sindel 1998), being competitive for space, light, water and nutrients (Wells et al. 1986), and very
competitive when mature (Cook 1999).
N. neesiana is resilient after cutting and grazing. Like other grasses, the intercalary meristems (at the base of each leaf) are
stimulated to grow by removal of the upper stems or leaves (Wheeler et al. 1999), an adaptation to vertebrate grazing, so plants
usually produce new flowering stems after mowing (Muyt 2001). Grass leaves also continue to elongate after being cut, and their
stems often return to an upright position after being flattened by wind or water (Wheeler et al. 1999).
N. neesiana has the capability of dispersing rapidly e.g. south western Europe (Verloove 2005) over long distances.
Its recorded impacts on biodiversity includes the ability to replace preferred indigenous vegetation (Wells et al. 1986), to cause
loss of species, loss of food sources for wildlife and seed damage to wildlife (Liebert 1996). Kirkpatrick et al. (1995) considered
it a threat to the Kangaroo grass – Blue Devil – Common Bog Rush Basalt Plains Grassland community, the main grassland type
of the Victorian basalt plains.
The seeds of various species of Stipeae have long been recognised as harmful to animal husbandry. Stipa capillata L. seeds
penetrate the coats and flesh of cattle, “often leading to mortality or seriously injuring the oral cavity” (Tsvelev 1984 p. 859). N.
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