What is a Threatened Ecological Community?

In NSW, ecological communities can be listed as Threatened Ecological Communities under the Threatened Species Conservation Act, 1995, in the categories of, Critically Endangered, Endangered or Vulnerable, depending on their risk of extinction. Ecological communities can also be listed as nationally threatened under the Commonwealths Environment Protection and Biodiversity Conservation Act, 1999.

How do Ecological Communities become threatened?

An ecological community may become threatened if it:

1. Undergoes a very large to moderate reduction in its geographic distribution;
2. Is geographically restricted and under pressure from a threatening process; or
3. Undergoes a very large to moderate reduction in ecological functioning.

The ecological functioning of an ecological community involves the processes that transfer energy and materials within that system. These include nutrient, oxygen and water cycles and flows. A reduction in this functioning may be indicated by any of the following:

1. change in community structure,
2. change in species composition,
3. disruption of ecological processes,
4. invasion and establishment of exotic species,
5. degradation of habitat, or
6. fragmentation of habitat.

A loss in ecological functioning or geographic distribution may occur for many reasons including pastoral and agricultural development, urban and infrastructure development, changed and inappropriate fire regimes, and other biotic or abiotic changes. For these reasons 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.

Some ecological communities such as the endangered ecological community, White Box-Yellow Box-Blakely’s Red Gum Woodland, have undergone such a large reduction in its ecological functioning and geographic distribution that less than 0.5% of its occurrence is estimated to retain pre-European levels of species diversity and composition. The loss of individual species in these communities or further reductions in their overall extent have a compounding effect on other species in the community as they lose their habitat, or their habitat is reduced or modified so that it is no longer adequate for them to reproduce and continue their life cycle.

An example of a community that has been listed due to threats facing it because of a restricted geographic distribution is the Hygrocybeae Community of Lane Cove Bushland Park. It is an assemblage of more than 20 fungi from the family Hygrophoraceae that is restricted to a core zone along the Gore Creek catchment in the Lane Cove Local Government Area in Sydney.

A nomination can be put by any member of the public to the NSW Scientific Committee to determine whether the level of threat facing the particular ecological community is sufficient to warrant protection under the law. For more information on the listing process for ecological communities (as well as species and populations) that have been nominated for listing under the Threatened Species Conservation Act 1995 click here.

For more information on nationally listed Threatened Ecological Communities see: http://www.environment.gov.au/biodiversity/threatened/index.html