Threatened ecological communities
Ecological communities are groups of plants and animals that occur together in a particular area. Any given ecological community may be distinguished from others by its set of characteristic species and the area in which it occurs. Ecological communities are complex, so correct diagnosis often requires specialist advice. The places they occur are typically characterised by a set of environmental conditions which define their suitable habitats. For example, the soil types, landforms and climatic conditions of a particular area.
What is a threatened ecological community?
The NSW Threatened Species Conservation Act 1995 (TSC Act) defines an ecological community as ‘an assemblage of species occupying a particular area’.
Ecological communities can be listed under the TSC Act as critically endangered, endangered or vulnerable, depending on their risk of extinction.
An ecological community may be considered threatened under the Threatened Species Conservation Regulation 2010 for one of three main reasons
- its distribution has been significantly reduced
- its distribution is so restricted the whole community is susceptible to significant threats, or
- the ecological function of the community is undergoing a significant decline
Reductions in distribution are typically related to historical and/or current clearing for development. Distribution may also be restricted through naturally rare environmental conditions that are essential to the community. Declines in the ecological function of a community may result from change in community structure,change in species composition,disruption of ecological processes,invasion and establishment of exotic species,or habitat degradation orfragmentation.
Consequently, many ecological communities have been cleared or degraded to such an extent that only a small amount of their original area resembles or functions in its natural state.
Why identify and manage threatened ecological communities?
By listing an ecological community as threatened, all component species of that community are also protected. This approach enables a more efficient use of limited resources than the single-species approach. It also overcomes bias towards charismatic species, protects both undiscovered species and the biological processes critical to maintaining a healthy environment.
What about degraded sites?
Much of the natural environment in NSW has been modified by human activities, fire and invading weeds and pests. Threatened ecological communities are often highly fragmented and most remnants show evidence of disturbance and degradation to varying degrees. The degree can be influenced by
However, the retained values of such remnants are often highly context-dependent. For example, smaller remnants may be in better condition and display greater resilience to future threats compared to some larger remnants.
A remnant can be part of a threatened ecological community with or without trees. Trees may be present as a canopy with little visible native ground-layer, or characteristic tree species may have been removed, leaving only the ground-layer component of the ecological community.
Degraded areas of native vegetation may still retain considerable conservation value. They may provide habitat critical to the survival of native plants and animals including threatened species. Such areas can often be rehabilitated and contribute to the recovery of the threatened ecological community.
Individual trees may provide an important resource to threatened animals, which are part of the ecological community. For example, large older trees may support a diverse and abundant array of insects and the animals that feed on them. They often have numerous hollows, cracks or fissures that provide shelter and nesting sites. Or they might act as ‘stepping-stones’ for fauna moving between larger, more complex remnants across an otherwise cleared landscape. Standing dead trees also provide critical shelter for fauna. In many landscapes, these important habitat resources are now more common in the form of isolated trees rather than in patches of vegetation.
Search for a threatened ecological community
You can view detailed profiles of each threatened ecological community. Search by keyword or geographic distribution.
Page last updated: 06 August 2012
