Stephen B. Johnson
Invasive Plants and Animals, New South Wales Department of Primary Industries, Locked Bag 6006, Orange, New South Wales 2800, Australia.
Cite this article as:
Johnson, S.B. (2013). Don’t let the truth get in the way of a good story. The declaration of weeds that affect the environment started in 1907 in New South Wales. Plant Protection Quarterly 28(3), 77-9.
It is often claimed that the declaration and management of weeds that impact on the environment is a relatively recent occurrence. This story has shaped the development of legislation, policy and investment in New South Wales weed management programs. Unfortunately, like most good stories, it is not entirely accurate. To claim that the management of weeds that impact environment values in New South Wales is only a recent development is to ignore the historical record. In saying this, there is some evidence to suggest that weeds that impact on environmental values are now better managed in New South Wales, particularly under the Noxious Weeds Act 1993 and the Threatened Species Conservation Act 1995.
This paper examines the first 25 years of weed declarations in New South Wales comparing these to current declarations. The paper summarises in excess of 1300 and 2100 declarations under the Local Government Act 1906 and the Local Government Act 1919 respectively. Weeds declared in New South Wales during the period 1907-1931 affected both primary production and the environment. The importance of some weeds then managed has waned such that stinkwort (Dittrichia graveolens L. Greuter) and inkweed (Phytolacca octandra L.) are of little current concern, and are now not declared. In contrast, many weed declarations are similar to those today, for example Bathurst and Noogoora burr (Xanthium spinosum L. and X. occidentale Bertol., respectively). In such cases we need to ask whether the battle against these weeds over the last 105 years has been successful.
Keywords: Noxious, native, exotic, impacts.
The New South Wales government has a long history of legislating to manage weeds that impact on primary production, the environment and the community, including on our cultural heritage. Although there was some parliamentary debate over possible legislative management of weeds well before the year 1900, it was not until the enactment of the New South Wales Local Government Extension Act 1906, and later the Local Government Act 1906, that Municipalities and Shires/Councils were able to apply to the State Governor to declare a plant (or animal) to be noxious within their area.
It was a requirement of the Local Government Extension Act 1906 that occupiers or owners were “to extirpate and destroy the plants or animals on the land”. Notice was to be served requiring such control within three months when any noxious plant or animal was found “growing or living upon any land” and that (if)
“at the expiration of such period, the plants or animals have not been so extirpated and destroyed or reasonable efforts have not been made to so extirpate and destroy them, the council may forthwith extirpate and destroy them and any reasonable expense so incurred by a council may be recovered in any court of competent jurisdiction from the occupier, or if there is no occupier from the owner of the land” [council also had powers of entry].
Councils were required to do the same on “any land vested in or leased by it or upon any public place or reserve under its care or management”.
Similar requirements were to be enforced under the superseding New South Wales Local Government Act 1919 in that all occupiers of land with noxious plants (and animals) were required to “destroy such plants and animals and…thereafter keep the land free therefrom”. Notices for control were to be “not less than two months” and councils could enter to “destroy noxious weeds and recover costs”. A £50 fine could be applied for failure to comply.
The Local Government Act 1919 was the chief legislative instrument for the management of weeds until a revision of that Act in the early 1990’s. At that time, the noxious weed requirements were removed from the 1919 Act and placed in the New South Wales Noxious Weeds Act 1993. Since then, local control authorities (generally local government areas) have been responsible for noxious weed control functions. [The revised New South Wales Local Government Act 1993 was also tabled in parliament at the same time]. Weed management in New South Wales has been aided by subsequent legislation, for example the New South Wales Threatened Species Conservation Act 1995 and legislative amendments to the Noxious Weeds Act 1993, for example Johnson et al. (2013).
This paper summarises the first 25 years of weed declarations in New South Wales (1907-1931). A comparison between these historic declarations and those of today is made. The most common weeds declared during the period 1907-1931 are listed and the possible reasons for declaring these weeds are examined. Whether or not the continued declaration of these species has been legislatively successful is discussed.
Copies of the New South Wales Government Gazette were examined at the State (Mitchell) Library of New South Wales, in Sydney. Notices made by Local Governments, Municipalities and Shires were listed in the index of each quarterly volume: only those relating to noxious plants were recorded. The collated data were sorted to remove duplicate notices (the same species declared in the same local government areas two or more times) and to standardise common and scientific name spelling and terminology. Genera and species names were checked using RBG&DT (2009-2013) and updated as necessary.
For ease of comparison between the different Acts listed above, this paper separates the data into two sets; firstly for declarations from 1907-1918; and secondly for declarations from 1919-1931. This paper reports on the identity of the top ranked weeds declared (by number of areas declaring the weed), the total number of plants declared during each time period, the number of exotic and native species declared and, for a first at that time, which species were declared across the state. The probable reason why these species were declared is summarised and compared to current (2012) declarations contained in Weed Control Order 28 of the Noxious Weeds Act 1993.
Results and discussion
Weeds declared noxious 1907-1931
Seventy eight weed taxa were declared noxious during 1907-1918 and 119 taxa were declared during 1919-1931. Only three taxa declared noxious during the first period were not declared after 1919.
Increased problems posed by ‘new and emerging’ problem species may be one reason why many more exotic species like Ailanthus altissima (Mill.) Swingle, Anredera cordifolia (Ten.) Steenis and Chondrilla juncea L. and natives like Cassinia arcuata R.Br., Kunzea ambigua (Sm.) Druce and Sclerolaena birchii (F. Muell.) Domin were declared after 1918.
There is a high degree of similarity in the top 20 ranked species declared under the Local Government Act 1906 (Local Government Extension Act 1906) and those declared under the Local Government Act 1919 (Table 1). Xanthium spinosum L., X. occidentale Bertol., the species aggregate known as Rubus fruticosus L. and Centaurea calcitrapa L. were the most commonly declared species during both periods. The year 1920 also saw the introduction of “all of state” declarations for the two Xanthium species, Hypericum perforatum L. and Moraea collina Thunb. (probably M flaccida Sweet and M. miniata Andrews).
Comparison of weeds declared noxious 1907-1931 to 2012
Of the 26 top ranked weeds during 1907-1931, eight are no longer declared, that is Cirsium vulgare (Savi) Ten., Dittrichia graveolens L. Greuter, Arctotheca calendula (L.) Levyns, Argemone ochroleuca Sweet, Datura stramonium L., Nicotiana glauca Graham, Phytolacca octandra L. and Solanum cinereum R.Br. There are likely to be many reasons for these removals including better control measures, but also that some of these species are now present in their full geographic range and that enforced control is no longer warranted. By way of contrast, all Opuntia, Lantana and former Rubus fruticosus species are still declared and this aids ongoing control and asset protection efforts; the latter two taxa being two of the original 20 Weeds of National Significance (WoNS). With only limited exceptions, nearly all top ranked species that were declared in 1907-1931 and that were declared in 2012 were Class 4 species in 2012 (Table 1): Class 4 noxious weeds are “Locally Controlled” and “pose a threat to primary production, the environment or human health, are widely distributed to an area to which the order applies and are likely to spread in the area or another area”.
Probable reasons weeds were/are declared
With notable exceptions, most weeds were declared in 1907-1931 for the purposes of primary production. It is likely that only eight (12%) of weeds declared during 1907-1918, and 11 (9%) during 1919-1931, had environmental or partial environmental/primary production impacts.
Having said this, it is also important to note that a small but significant number of what are considered today to be environmental weeds were first declared during this period, particularly during 1907, that is Chrysanthemoides monilifera subsp. rotundata (DC.) Norl., Ulex europaeus L. and Eichhornia crassipes (Mart.) Solms, but also in 1911 with Cytisus scoparius subsp. scoparius (L.) Link, and Anredera cordifolia in 1920.
A case study involving the species aggregate that until recently was known as Rubus fruticosus best illustrates how legislation to enable the management of weeds impacting on environmental values is not a recent occurrence. While the passing of time now clouds the reason why this species aggregate was first declared in New South Wales, in the Lismore Municipality in 1907, a statement accompanying the declaration for the same taxa in the Municipality of Kiama in 1921 indicates that it was “becoming detrimental to farm and home [native?] lands”. While there is some evidence to suggest that weeds that impact on environmental values are now better managed in New South Wales, particularly under the Noxious Weeds Act 1993 and the Threatened Species Conservation Act 1995, the historical record clearly suggests that legislation was used to manage weeds that impacted the environment from as early as 1907.
Exotic and native species declarations
Native plant species have both positive and negative impacts on primary production, the environment and the community. While the negative impacts of native plants probably most impacted on primary production in the past, over-abundance of these species (often the result of human activity) is also likely to have impacted environmental values in those times.
Eight native Australian weed taxa (10%) were declared noxious during 1907-1918, while these eight and an additional eight native weeds (a total of 13%) were declared during 1919-1931. The eight taxa common to both time periods were Bursaria spinosa Cav., a Macrozamia spp., Olearia viscidula (F.Muell.) Benth., Persicaria hydropiper (L.) Delarbre, Salsola australis R.Br., Sclerolaena muricata (Moq.) Domin, Solanum cinereum and Swainsona galegifolia (Andrews) R.Br. As stated earlier, it is not clear why many of these species were declared, excepting those which had explicit primary production impacts, e.g. S. galegifolia and the Macrozamia species which almost certainly caused animal poisoning.
Has the continued declaration of weeds been successful?
Around 40% of the weeds first declared during the period 1907-1931 are still declared over 105 years later. Additionally, over half the top ranked weeds from this period now exclusively have Class 4 (Locally Controlled) declarations. This clearly indicates that the original control measures that encouraged eradication, that is initially ‘extirpation and destruction’, and later ‘destruction and keeping the land free of these weeds’ have clearly not been successful.
The primary aim of legislation relating to noxious weeds is to remove weed externalities such that spread from infested areas to non-infested areas (covering the entire geographic range of spread) has not been achieved, as the relative large number of current declarations of these species illustrates. This generalisation appears to hold true for nearly all of the top ranked weeds. The most obvious exception to the above generalisation is that of E. crassipes, which is still largely restricted to eastern New South Wales, even though relatively small infestations are well known from several areas within the Murray Darling basin.
Of those species removed from declaration, it is likely that newer forms of control, including biological control, have reduced the threats posed by the species, as have newer technologies and practices.
In conclusion, while it is true that declaration may have helped slow weed spread since 1907, two inescapable conclusions remain:
that there is a need to continue to review noxious weed declarations in New South Wales, particularly those species that are currently Class 4 (Locally Controlled) weeds to ensure that legislative outcomes are continuing to be achieved; and
that, in a climatically diverse state such as New South Wales, some weeds obviously have no boundaries as to how far they can spread.
Johnson, S.B., Blackmore, P.J. and Lisle, S.D. (2013). Noxious Weeds Act 1993 – Moving with the times. What does this mean to you? Proceedings of the 17th NSW Weeds Conference, ed. H. Wu. (Weed Society of New South Wales, Wahroonga, Sydney).
RBG&DT, Royal Botanic Gardens and Domain Trust (2009-2013). PlantNET – the plant information network system of the Royal Botanic Gardens and Domain Trust, Sydney, Australia. http://plantnet.rbgsyd.nsw.gov.au (last accessed April 2013).