Vegetation

2011

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

Box 5.2  Connectivity conservation in Australian landscapes

Connectivity conservation is an increasingly important conservation approach to land use and management, in Australia as elsewhere. Connectivity conservation areas interconnect protected areas, help maintain large-scale natural Australian landscapes and ecosystem processes, and are a natural and critical partner in biodiversity conservation to the National Reserve System. These areas are a critical conservation response to climate change. They provide opportunities for species to move, interact, adapt and evolve as higher temperatures and changed rainfall patterns cause ecosystem shifts at a landscape scale.

By 2011, seven large-scale connectivity conservation areas had been initiated to help protect the integrity and resilience of many Australian ecosystems. Major large-scale connectivity conservation areas are found in the east (the 2800-kilometre Great Eastern Ranges Corridor); in the north and north west (the 3000-kilometre Northern Australia Tropical Savannah Lands Corridor, including the Kimberley Landscape Conservation Area); the south west (the 1000-kilometre Gondwana Link); and through the centre (the 3500-kilometre Trans-Australia Ecolink Corridor) of the Australian continent. Other important large-scale corridors are located in the borderlands of South Australia, Victoria and New South Wales (Habitat 141) and in the Victorian alps (Biolinks).

The connectivity areas have been initiated by grass roots organisations, nongovernment conservation organisations, governments or a combination of these. The connectivity areas are managed to varying degrees. A central guiding vision has provided management direction, with management actions helping to maintain biodiversity and critical ecosystem processes, and respond to threats. Management has also included strategies for retaining opportunities for long-distance biological movements, retaining the integrity of hydro-ecological systems, sustaining resilience to global climate change, minimising human disturbances at local and regional scales, and protecting opportunities for species interactions and maintaining evolutionary processes. Connectivity conservation management frameworks are providing a systematic approach to conservation assessment, planning and management, and over time will include evaluation of effectiveness.

Governance of these large-scale corridors has favoured decentralised approaches that include multiple partnerships, and a shared vision has been developed for the corridor as a whole and within component links. This is important, given the needs of local areas relative to the entire corridor. On-ground management has been achieved through conservation programs and multiple individual efforts. The positive involvement of people from all walks of life in connectivity conservation work has been a small social phenomenon that can only be expected to grow, and reflects important changes in attitudes to the environment throughout the community. A connectivity conservation management approach, however, requires reliable resourcing, and supportive planning and policies, to consolidate its role in facilitating biodiversity conservation.

Source: Worboys & Pulsford128

The discussion in Section 4 of this chapter, and the corresponding discussion in Chapter 8: Biodiversity reviewed the effectiveness of current approaches to managing Australia’s land environment. In essence, we are succeeding in managing some parts of our land environment and some of our production systems for resilient outcomes. In others, however, our efforts seem to be having little impact, and the resilience of the land environment will decline unless our management changes or becomes more effective. Ultimately, the outcomes of our management strategies will determine the outlook for Australia’s land environment, which we discuss in Section 7.

Kanowski P, McKenzie N (2011). Land: Vegetation. In: Australia state of the environment 2011, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/science/soe/2011-report/5-land/5-resilience/5-2-vegetation, DOI 10.4226/94/58b6585f94911