Preserving Biodiversity: Threats and Conservation Efforts in Rural South Australia

South Australia has increased the proportion of its land set aside for biodiversity conservation, although much work remains to be done. However, the State’s extinction debt is increasing rapidly.

Effective monitoring and adaptive management is lacking. Furthermore, efforts to estimate counterfactuals are often lacking. This makes it hard to develop conservation goals that enhance the resilience of species for the lowest cost.

Threats to Biodiversity

The State’s biodiversity values are at serious risk from a range of threats. Species and ecological communities are losing their ranges, being eliminated from their sites of occurrence, and their population sizes and numbers are declining.

These trends are caused by a range of human activities and pressures. They include clearing, habitat loss and fragmentation; water extraction; agricultural practices (including fertilisers and pesticides); land-use changes; fire; invasive species; water pollution and other human activities (e.g. urbanisation). These factors are not exclusive and can interact with each other to cause the greatest impacts on biodiversity.

For example, weeds may increase the stress on native species by crowding out their space and competing for resources. Similarly, habitat destruction by humans can make it more difficult for indigenous peoples to sustain traditional uses of natural resources (e.g. hunting and gathering). The same human activities that reduce biodiversity also contribute to its decline by reducing their resilience.

Efforts to preserve and restore biodiversity are important. However, their effects are limited by the availability of financial, technical and other resources. State Government funding for the environment has been declining in real terms over time, and is currently at around 1.0-1.5% of State budget expenditure. This is far lower than what is needed to protect and enhance the State’s biodiversity.

There are a number of steps that could be taken to improve biodiversity outcomes in South Australia. For example, revegetation and ecological restoration should be promoted with the goal of reducing the extinction risk of multiple species at once, rather than just the single species being planted. This would require better knowledge of which species are required for each ecosystem and the appropriate scale at which they need to be planted.

Other potential improvements include a greater emphasis on restoring the natural water cycles of rivers and wetlands, rather than simply pumping in water; less-intense agriculture that minimises the damage done to soil and riparian systems; and a shift towards conservation-friendly land-use practices (e.g. land-sparing approaches).

Lists of threatened species are maintained at different spatial scales. The International Union for the Conservation of Nature maintains the Red List of threatened species globally; the Commonwealth EPBC Act lists are maintained at the national level; and each State maintains its own state-based list of animal and plant species. These lists are incomplete and do not represent the full diversity of the State’s biodiversity (for example, invertebrates are not considered as animals).

Climate Change

At a broad scale, the biodiversity of South Australia’s native flora is declining. Approximately 12% of South Australia’s plant taxa are threatened with extinction. This is due to the loss and degradation of habitat, including land clearing, which represents the biggest threat to terrestrial plants in SA. However, native plant species are also being impacted by other factors such as fire, salinity, water logging, and climate change (Bradshaw 2012).

Fortunately, there are a variety of strategies that can be employed to improve biodiversity outcomes on agricultural land. These include encouraging farmers to adopt ‘land-sparing’ agricultural practices that conserve native vegetation, funding infrastructure to prevent stock grazing of remnant vegetation and riparian zones, providing support for revegetation programs on agricultural land, and improving the effectiveness of biological pest control through research and monitoring.

In addition, a range of State and Commonwealth programs are designed to improve biodiversity on private land, through conservation training and skills development, funding of environmental projects, and provision for community groups to be involved in the planning and implementation of conservation efforts. Another important aspect is facilitating the involvement of Indigenous communities in the management and protection of their traditional country. This includes facilitating the documentation and recording of Indigenous biocultural knowledge on privately owned land, as well as the establishment of Indigenous Protected Areas.

Other approaches are to encourage private landowners to enter into Heritage Agreements, which essentially set aside land for conservation purposes and guarantee that this remains the case even after a property is sold or transferred ownership. The State government is also increasing the funding, functions and independence of the Environmental Protection Agency, which can help ensure that biodiversity is considered in any decisions regarding natural resource extraction.

The simplest way to increase biodiversity is through environmental stewardship, where individuals or community groups take responsibility for managing a piece of land, such as a backyard, with the aim of conserving it. This can be done by setting up and maintaining bird nesting hollows, planting trees to attract wildlife, removing invasive species from the environment, and promoting sustainable farming practices that minimise the impact on biodiversity.

Invasive Species

Species that are not native to an ecosystem – whether plants, animals or diseases – can pose a serious threat. They may eat or parasitise native species, or outcompete them for resources, or even displace them from their habitat. They can also disrupt ecosystems and bring new diseases to humans. Invasive species are one of the main drivers of ecosystem change – they are a significant global threat to biodiversity.

Invasive species are often spread by human activities, including travel, trade, transport and agricultural practices (including inappropriate stocking rates and feeding regimes) and intentional or accidental introductions. They threaten the health and function of natural environments, the economy and human wellbeing – affecting recreation, water resources, food production, biodiversity and ecosystem services, agriculture, land values and property and cultural heritage. They can impact the survival of many native species and can have a long-term negative effect on regional economies and communities.

Several State and private organisations are doing good work on reducing the impacts of invasive species. These include promoting land-sparing approaches to agriculture that minimise the loss of native biodiversity, fostering the development of more bird-friendly pest control options and supporting ecological restoration initiatives that target areas with high levels of extinction risk. More research and funding needs to be invested in developing methods that will allow revegetation efforts to optimise the benefits of restoring and preserving existing biodiversity.

More can be done to encourage broader engagement with Aboriginal peoples in the management of land for conservation purposes and to foster awareness of Indigenous culture. The expansion of Indigenous Protected Areas has been beneficial, but there is much more to be achieved. Creating more opportunities for Aboriginal communities to participate in the planning of environmental protection strategies within National Parks would be another step forward.

Government and business leaders should ensure that all major development within National Parks is guided by principles of ‘comprehensive, adequate and representative’ reserve systems (Government of South Australia 2018). This approach allows for the inclusion of important species, communities and ecosystems that have special needs, particularly those that are mobile or migratory, and that provide natural refuges. It also ensures that reserves adequately represent the ecological communities most at risk.

Conservation Efforts

While it is important to preserve the natural ecosystems, a vital part of biodiversity conservation is engaging with local communities. This includes educating them about the importance of biodiversity and the need to protect it, and providing support for them in doing so. It also means promoting and supporting a holistic approach to land management, which promotes sustainable long-term business, healthy native species and ecosystems, and resilient communities in the face of changing environmental conditions.

In South Australia, there are a number of initiatives being undertaken to improve the conservation status of our native flora and fauna. These include the setting of measurable targets for species recovery, increasing funding for State-based biodiversity conservation programs, and fostering greater community engagement in conservation through the various State- and privately run initiatives.

However, there is concern that these efforts are not keeping pace with the actual rate of decline of biodiversity in our country. This is largely due to the fact that our listing processes for threatened species and ecological communities are not keeping up with the pace of decline, and that they have limited effectiveness in improving land management or biodiversity outcomes.

Furthermore, the large proportion of the State’s biodiversity occurring outside of formal parks and reserves means that individual land owners are the main drivers of biodiversity conservation in rural areas. This is why it is so important to encourage people to retain any areas of natural habitat on their properties, and to remove threats, e.g. through the removal of invasive plants and through the implementation of conservation-focussed agricultural practices.

A major challenge is to create more meaningful opportunities for landowners to engage with and participate in conservation activities on their properties, in particular the establishment of conservation covenants on property titles that limit the rights (e.g. to graze or clear) in a particular way. In this context, the voluntary Heritage Agreements program (Government of South Australia 2018) is one example that has some success, although it can have perverse outcomes if not managed appropriately.

The creation of new areas of natural vegetation through revegetation projects is also a crucial element in improving biodiversity conservation, but this work should be designed and executed with an eye to achieving specific, measurable conservation outcomes. This includes ensuring that new vegetation has sufficient species diversity to allow for species-specific interactions, and that the plants are a good fit with the landscape in which they are planted (as well as having the required water and nutrient budget).