At a glance
Resilience is a key underpinning principle of Australia’s Biodiversity Conservation Strategy 2010–2030, as well as state and territory, and regional biodiversity strategies. The definition of resilience in biodiversity strategies and policies is still relatively ambiguous, and needs to be more clearly quantified and articulated to measure the success of these strategies. Ecological resilience is generally defined as the ability of ecosystems to resist permanent structural change and maintain ecosystem functions.
Australia’s biodiversity is well adapted to variable climate conditions and to a certain frequency of extreme events. However, the current rate and magnitude of change in climate, compounded by other pressures, are beginning to seriously challenge the natural adaptive capacity of our biodiversity. There are many initiatives and activities being undertaken across Australia, from local to national scales, that will improve the resilience of our biodiversity to future pressures. However, there is growing evidence that some vulnerable ecosystems are undergoing permanent structural change because of extreme climate impacts, signalling a clear loss of resilience in these systems. Further work is required to understand thresholds before tipping points are reached beyond which irreversible changes to ecosystems occur.
Ecosystems globally have always experienced environmental change and natural disturbances, but the effects of human activity (e.g. land conversion, carbon emissions, invasive species) are increasing both the rate and the intensity of change. Strengthening and maintaining the resilience of biodiversity to this change is a key underpinning principle of Australia’s Biodiversity Conservation Strategy 2010–2030. The strategy identifies 3 national priorities for action to help stop decline in biodiversity. One of these is ‘Building ecosystem resilience in a changing climate by: protecting biodiversity, maintaining and re-establishing ecosystem function, and reducing threats to biodiversity’. The management of biodiversity for resilience is also increasingly embedded in state and territory, regional and local-level biodiversity strategies.
Resilience is a concept with numerous definitions in ecological sciences. Initially, the focus of resilience was on the stability of ecosystem processes and the speed with which they recover these processes following disturbance. This has gradually been replaced by a broader concept of ‘ecological resilience’, defined as the ability of ecosystems to resist regime shifts and maintain ecosystem functions, potentially through internal reorganisation (i.e. their ‘adaptive capacity’) (Oliver et al. 2015). Regime shifts are defined as large, persistent changes in the structure and function of systems, with significant impacts on the suite of ecosystem services provided by these systems.
Although much of the discussion about resilience in policy and biodiversity management is derived from a concern about the impact of climate change, changes to climate will interact with other disturbances such as land-use change, invasive species, disease and pathogens, and other agents of change, resulting in ‘threat syndromes’. Threat syndromes occur when several threats, both present and future, interact to undermine resilience and the continued persistence of certain types of biodiversity. It is most likely that changes to ecosystems and biodiversity will come about as a result of threat syndromes rather than from the operation of 1 agent (Murphy et al. 2012). Approaches to resilience that incorporate broad thinking about environmental change appear most likely to ensure good outcomes.