Independence Group Sustainability Report 2019

trust in accordance with the Australian Government Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act). The trust, known as the Great Victoria Desert Biodiversity Trust, was established by the Tropicana Joint Venture to deliver lasting net-environmental benefit to the Great Victoria Desert through the provision of funds connected to the offsets strategy. The trust represents a new structure of offset delivery and operates as a unique partnership model between industry and government. The Lake Mackay project area is 400km west-north-west of Alice Springs and sits within the Great Sandy Desert Bioregion comprised predominantly of semi-arid sand plains and sand dunes. The project is named after Lake Mackay, a vast saline lake that straddles the border of Western Australia and Northern Territory, and is the fourth largest lake in Australia, providing an important habitat for birds following flooding. While IGO’s exploration activities are not close to the lake, our practices are targeted at minimising impacts across our entire tenure. A holistic approach to complex and cumulative impacts IGO seeks to take a holistic approach to our impact management, informed by a broader perspective gained through external sensing and adherence to our internal standards. Environmental impacts are typically complex and often cumulative. Evidence gathered over the past forty years has demonstrated that the greatest impact on Australia’s native mammals comes from a combination of habitat loss, predation by feral animals, modified fire regimes and grazing. Whilst large scale land clearing in Australia is largely a thing of the past, both fire and grazing regimes have intensified substantially in recent decades in ways that have made many plant communities less complex and more open, creating conditions that are favoured by introduced species and contribute to the decline in native mammals. Other impact interactions include those between invasive plants (particularly pasture grass) and fire, which is part of a positive feedback loop. In this situation, fire encourages growth of invasive grasses, which in turn, provides more biomass and reduces the time between fires. It has also been demonstrated that fragmented woodland landscapes have more vertebrate pests than intact woodlands. Beyond local-scale impacts, climate change is predicted to exacerbate the impacts associated with habitat fragmentation and invasive species. Climate change is affecting the viability, distribution and occurrence of native species. It is well established that this is a major factor that will result in, among other things, some native species migrating to seek more favourable conditions and contracting to refuges. Climate change is also likely to affect the viability, distribution and occurrence of invasive species. The large number of introduced plant species in Australia may become invasive if changing climatic conditions favour them. Because climate change will enhance existing threats, there is a general view that the capacity of the environment to adapt to climate change will be improved if other impacts are addressed or mitigated. Land clearing and rehabilitation Land clearing is a fundamental pressure on the environment. It causes the loss, fragmentation and degradation of native habitats and ecosystems; impacts soils through erosion and loss of propagules and nutrients; and causes sedimentation and pollution of water bodies. The fragmentation and degradation of vegetation can, in turn, disrupt essential ecosystem functions such as the provision of habitats for specific species and processes such as pollination, seed dispersal and regeneration. Smaller fragments of remnant vegetation are particularly vulnerable to invasive species and fire. Half of Australia’s species currently listed as threatened under the EPBC Act are considered at risk from habitat fragmentation. This impact is compounded by the legacy of extensive historical clearing across Australia. This presents a considerable challenge for land managers because addressing historical impacts can be costly, difficult and is not always successful. Approximately 44 per cent of Australia’s forests and woodlands have been cleared since European settlement, 39 per cent was cleared before 1972. Currently IGO’s main environmental impact is land clearing. Given the current and foreseeable technologies required for exploration, we, like other explorers, need to be physically on the land to explore. We do this by conducting on-ground electromagnetic surveys, seismic surveys, surface soil sampling and drilling. This requires the creation of cleared tracks for the passage of vehicles and whilst the need for these tracks is temporary, vegetation is unavoidably removed. IGO SUSTAINABILITY REPORT 2019 — 39