The resilience of vegetation to pressures depends on the extent to which essential ecological processes have been, and can be, maintained. Resilience to current pressures is relatively high where vegetation is largely intact on a landscape scale, connectivity between landscape elements has been maintained, and levels of disturbance are within ecological thresholds.
Therefore, land managed for nature conservation generally has a relatively high level of resilience, although this may be affected by pressures that are difficult to manage, such as invasive species. Conversely, in much of the intensive land-use zone, and increasingly in peri-urban and coastal zones where most vegetation occurs as disconnected remnants, resilience is likely to be poor or diminishing because of both legacy effects and current pressures. Proactive restoration may be necessary to rebuild resilience in these landscapes.125
Measures to improve the resilience of biodiversity (see Chapter 8: Biodiversity) also apply more generally to vegetation. A set of principles has emerged to foster resilience in landscapes managed for production; these also apply to landscapes fragmented by other forms of development.53 The principles encompass both pattern and process-oriented management strategies:
Landscapes should include structurally characteristic patches of native vegetation, corridors and stepping stones between them, a structurally complex matrix, and buffers around sensitive areas. Management should maintain a diversity of species within and across functional groups. Highly focused management actions may be required to maintain keystone species and threatened species, and to control invasive species. Fischer et al.126
Implementation of these principles has also been discussed in the context of strategies that will improve the resilience of Australian ecosystems to climate change. As noted in Section 3.1, recent assessments52,127 suggest that climate change may cause profound changes in the character and spatial distribution of many Australian vegetation communities. Some communities—such as those at higher elevations in the wet tropics—are at risk of disappearing completely.
Partly for this reason, the maintenance or re-creation of vegetation corridors that provide connectivity across landscapes is one of the most important means of improving the resilience of vegetation to both current and future pressures, as long as the potential drawbacks of corridors, such as facilitating the movement of invasive species, are managed.126 Aspirations and initiatives to establish connectivity on a large scale in Australian landscapes have been described by Worboys and Pulsford128 (Box 5.1), and are represented in Figure 5.32.
Other components of the management strategies identified by Fischer et al.126 include maintaining vegetation composition, structure and regeneration processes; managing key and threatened plant and animal species; and managing threatening processes such as invasive species and inappropriate fire regimes. Implementation of each of these is necessary to improve the resilience of vegetation to current and future pressures, including climate change.52