6 – Developing the desert – potential effects on wildlife 71 channels could increase the persistence of introduced house mice, native rodents such as long-haired rats, brown snakes, and many species of mosquitoes and other biting insects. For example, dense populations of the highly venomous eastern brown snake (Pseudonaja textilis) use burrows in the banks of irrigation canals in the Murrumbidgee Irrigation Area (Whitaker and Shine 2003), where the snakes feed on house mice, and move over much of the agricultural landscape during warm months of the year. Dense populations of native and introduced species of rodents have also established in irrigated regions of south-east Asia (Aplin et al. 2003), damaging crops and livelihoods. Increased reliability of water and concentration of food in cropping areas can also be invasion hubs for feral pigs, cane toads (Letnic et al. 2014) and other invasive species (Letnic et al. 2015). Irrigation areas could also promote establishment of tropical disease organisms. Scenario 2: Fixation of bust-period conditions Depletion of ground and surface waters will prolong dry conditions, reducing opportunities for aquatic organisms to breed (see Chapters 3–5). Vegetation will be stressed woody plants reliant on deep water will die and the lack of shade and refuge they provide will have flow-on effects for the remaining flora and fauna (Wardle et al. 2015). Loss or fragmentation of refuge habitats from surface mining activities will reduce the utility of these habitats as refuges. Over time, reduced numbers of refuge-dependent organisms will lead to losses of their local populations. Managing the effects of irrigation and mining Monitoring how irrigation and mining affect animals, plants and other organisms at local and regional scales is essential, if these activities proceed across the Lake Eyre Basin, with clear trigger points identified if any indicators fall outside previously agreed norms. There is, at present, very little indication that regional policy and planning documents understand the importance of such evaluation (e.g. Northern Australia Land and Water Taskforce 2009 Australian Government 2014). Changes in land use would also need to be coordinated across industries. For example, water remoteness is a well-established concept in managing rangeland pastoralism, as it provides relief from grazing pressure (Fensham and Fairfax 2008). Therefore, any new water points or larger irrigated areas arising from development would need to be considered in the landscape context. We are still discovering the full extent of the dynamics of arid Australia, as witnessed by the extreme years in 2010–11. The intense ‘greening’ in these years led to unprecedented irruptions of small mammals, invertebrates and frog populations, migrations of species outside their known ranges, novel interactions among species, and greatly increased risks of predation and wildfire (Wardle et al. 2013). The greening also formed a major carbon sink, with an extraordinary 60% of global carbon being taken up by the growth of vegetation in Australia’s arid interior (Poulter et al. 2014). Managing broad-scale developments under such dynamic conditions will not be easy. What we can expect is for the already erratic dynamics of the Lake Eyre Basin to increase due to global climate change (Greenville et al. 2012 Greenville et al. 2013).
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