Resilience is the ability of the environment to withstand or recover from a shock or disturbance. Although the concept of resilience was developed and is mainly used in relation to ecosystems, it is a valuable concept across the environment and in environmental management. Effective environmental management aims to maximise the health or adaptability of the environment to improve its resilience to current, ongoing and future pressures. In SoE 2016, each thematic report discusses what resilience means for that theme.

Resilience concepts can potentially help us to recognise that, although some level of change is inevitable and normal, change that is too frequent or too rapid can lead to abrupt changes in the environment that may be very difficult or impossible to reverse.

The terms ‘tipping points’ and ‘boundaries’ are often used in relation to abrupt and irreversible changes. A tipping point can be regarded as an ecological threshold beyond which major change becomes inevitable. A boundary is a human-determined value that sets the distance from a tipping point that a society is prepared to maintain (see Rockström et al. 2009).

In general terms, Australia’s natural and cultural systems can be considered resilient in terms of resisting and recovering from shocks and disturbance, including the natural variability and change of the environment for which Australia is well known. For example, Australia’s biodiversity is renowned for its ability to deal with very significant variability (fire, extended periods of dry or wet, extreme weather events such as cyclones). During the past few decades, we have learnt more about the multitude of strategies that different species employ to provide resilience to change.

However, the extent to which Australia’s natural and cultural systems will continue to demonstrate resilience in the face of trends and shocks remains to be seen. Although Australia’s biodiversity is well adapted to past change, including a certain frequency of extreme climate events, it may not be well adapted to future rates of environmental change. The reduced quality and connectivity of the habitat of many species may further diminish their resilience to such change.

Evidence shows that some tipping points have already been passed in Australia. For example, researchers in southern Western Australia have documented change in the structure and composition of Australian temperate reef communities, which, in the past 5 years, have lost their defining kelp forests and become dominated by persistent seaweed turfs (Wernberg et al. 2016).

Healthy ecosystems are better able to replace lost organisms with the next generation, and areas of high biodiversity are more likely to contain species that can withstand a particular disturbance. Bleached coral reefs have recently fully recovered in remote areas that are free from other human pressures (Gilmour et al. 2013), but the same cannot be said for reefs exposed to heavy human use.

The cumulative impact of multiple pressures may also affect the resilience of the environment. A system may be resilient in the face of one or a few pressures, but this may break down as pressures of different types and magnitudes accumulate, or as tipping points are passed. Management actions, such as environmental watering, reduction of invasive species and management of competition, may only have a significant beneficial impact on resilience if they are undertaken at a sufficient scale and with appropriate timing to address the pressures. The eradication of cats, rabbits, rats and mice from Macquarie Island is an example of actions that were sufficient to completely remove invasive species and allow ecosystem recovery.

Science and investments by governments, combined with the efforts of landowners, communities and environment organisations working on-ground, are identifying opportunities for managing the Australian environment in ways that retain or rebuild the resilience needed to cope with future pressures. Examples include the following:

• The National Landcare Programme supports actions by communities working in conjunction with land managers and policy-makers to restore habitat and ecosystems, increase the conservation estate, identify and protect refuges, and restore connectivity to degraded landscapes.
• The Murray–Darling Basin Plan is helping to manage resilience in one of our most significant inland water resource basins by ensuring that water resources are not overallocated or overused, thereby providing a buffer for changing conditions.
• The large and expanding Indigenous Protected Areas estate builds capacity within Indigenous communities to manage land and sea Country in ways that benefit both the wellbeing of their community and biodiversity.

Structured scenarios and active adaptive management are 2 useful tools for building resilience that are sometimes used by planners, communities and decision-makers (Folke et al. 2002).

Scenario exercises that produce projections or if–then case studies (e.g. if we follow scenario A, then the expected outcome for the future is B) can help to assess potential impacts of change on socio-ecological systems (Evans et al. 2015), and to identify policies and management actions that might attain or avoid particular future outcomes (Folke et al. 2002).

Adaptive management is informed by on-ground observations of the effectiveness of actions. Adaptive management is suited to building or maintaining resilience because it acknowledges that all systems are subject to variability and change, is flexible, encourages learning through evaluation, and promotes the capacity to innovate in light of evolving understanding and circumstances (see Folke et al. 2002).