Abstract: The Murray-Darling Basin is a Social-Ecological System (SES) of major importance to Australia and includes extensive wetland areas in the north western parts of New South Wales. Historical land use has been extensive grazing; during wet periods the livestock were moved out of the wetlands and moved back in as the water receded. Recent land use changes include the building of major dams for irrigation water, and this has meant a reduction in the frequency and extent of flooding, and most of the wetlands have been continually grazed. Also, machinery capable of cultivating the very heavy textured soils became available and so dryland cropping became a major enterprise. With the reduction in flooding, many of these wetland sites have been seriously degraded. In recent years lippia, Phyla canescens (Kunth) Greene has had major impacts on parts of this SES. Lippia is a perennial that grows mat-like between other species of plants and may spread to produce virtually a mono-specific stand. The domestic livestock carrying capacity of the land becomes more or less zero and the conservation value of the wetlands is also dramatically decreased. Therefore, invasion of these wetlands by lippia has had and will continue to have, a major impact on the future trajectory of the whole SES in terms of its resilience, adaptability and transformability.
Whalley, R.D.B., Price, J.N., Macdonald, M.J., Berney, P.J., 2010, The impact of Lippia on the social-ecological systems of the Gwydir Wetlands, and Macquarie Marshes in northern NSW, Conference Paper, viewed 03 April 2020, https://www.nintione.com.au/?p=3560.