此物種詳細資訊 Northern Territory
來源： Mack and Lonsdale, 2002
Mimosa pigra was probably introduced to the Northern Territory, Australia, at the Darwin Botanic Gardens in the 20 years prior to 1891, either accidentally in seed samples, or intentionally, as a curiosity, because of its sensitive leaves (Miller and Lonsdale 1987, in Walden et al. 1999).
It is now one of the worst environmental weeds in Australia. It causes dense infestations that may either reduce biodiversity or compete with pasture grasses and hinder livestock access to water. It poses great a threat to the pastoral and tourism industries. The plant thrives in seasonally inundated areas and has invaded paper-bark (Melaleuca sp.) swamp-forests. In the Northern Territory it covers more than 800 square km.
In northern Australia the recommended strategy for controlling mimosa is to prevent initial invasion of the weed, eradicate small infestations by physical or chemical means and, for large infestations adopt an integrated approach involving biological control, herbicide application, mechanical removal, fire and pasture management. A typical integrated control program would include appropriate survey and mapping, chemical control, mechanical control, and burning. Mechanical chaining and rolling of dead stems to compact the fuel may assist burning, or be a useful step before spraying with herbicides. The area should then be protected from grazing and fire for at least one year to allow the pasture to establish. Any regenerating mimosa plants should be spot treated and when livestock are introduced, grazing pressures should be closely monitored (Walden et al. 1999). Managing grazing so as to encourage native vegetation to establish has the effect of increasing the competitive pressures imposed on mimosa, limiting its ability to invade. For example, culling feral water buffalo (part of the Brucellosis and Tuberculosis Eradication Campaign) allowed floodplain grasses to regenerate (Holding Undated).
To date, eleven species have been released, including nine species of insects and two species of pathogenic fungi (Rea 1998, in Walden et al. 1999). All have established in the field except for the most recently released seed-feeding insects, Sibinia fastigiata and Chalcodermus serripes, for which it is too early to confirm establishment (Walden et al. 1999). Five are persisting: the stem-mining moths (Neurostrota gunniella and Carmenta mimosa), the seed-feeding bruchid (Acanthoscelides puniceus), the flower-feeding weevil (Coelocephalapion pigrae), and the root breeding leaf beetle (Malacorhinus irregularis). The root breeding leaf beetle is heavily damaging seedlings in at least one site. Apparently, bulldozing large sites into smaller blocks may increase the impact of the biological control agents by improving their spread (Holding Undated). Although the agents released collectively damage vegetative and reproductive parts of the plant, mature leaves and roots remain largely undamaged. For this reason, biological control is not sufficient to achieve total control of mimosa and other control measures are necessary. Selection of further biological control agents is currently focusing on identifying agents that attack the mature leaves or roots of M. pigra (Walden et al. 1999).
Chemical control (via aerial application) is costly. In Australia it is most effective in the wet season, however it rarely kills all plants and there is some regeneration from the seed bank. In addition, chemical control is of limited use for mimosa infestations in paper-bark swamps (Holding Undated). The herbicide tebuthiuron has been used widely in the Northern Territory of Australia for control of the wetland weed M. pigra since the late 1980s. A risk assessment of tebuthiuron concluded that it represents a signficant and prolonged risk to native freshwater plant species, particularly phytoplankton and floating macrophytes, while not presenting any great risk to vertebrates or freshwater invertebrates. However the known ecological and economic impacts caused by M. pigra probably outweigh the overall ecological risks of tebuthiuron (van Dam et al. 1999).
棲地改變: The yellow-billed Egret (Mesophoyx intermedia) is listed as Least Concern (LC) in the IUCN Red List of Threatened Species. Its habitat in the Northern Territory of Australia is under threat due to burning, grazing and the spread of invasive alien plants Mimosa pigra and Salvinia molesta. The introduced feral buffalo (Bubalus bubalis) is also a threat causing breakes in the levees leading to salt intrusion and accumulation of salt settlement (BirdLife International 2009).
經濟 /民生: In northern Australia, as early as 1981, the economic effects of dense mimosa infestations started to affect the tourist industry (due to decreased access to wetlands) (Miller et al. 1981, in Walden et al. 1999).
最後修改 ： 30/05/2006 3:10:55 p.m.