1. GENERAL DEFINITIONS
A naturally occurring biological assemblage that occurs in a particular type of habitat.
Note: The scale at which ecological communities are defined will often depend on the level of
A threatened ecological community (TEC) is one which is found to fit into one of the following
Possible threatened ecological communities that do not meet survey criteria are added to DEC’s
adequately known, are rare but not threatened, or meet criteria for Near Threatened, or that have
been recently removed from the threatened list, are placed in Priority 4. These ecological
communities require regular monitoring. Conservation Dependent ecological communities are
placed in Priority 5.
An assemblage is a defined group of biological entities.
includes the abiotic factors (eg. substrate and topography), and the biotic factors.
Occurrence: a discrete example of an ecological community, separated from other examples of
the same community by more than 20 metres of a different ecological community, an artificial
surface or a totally destroyed community.
By ensuring that every discrete occurrence is recognised and recorded future changes in status
“An ecological community that has been searched for thoroughly in most likely habitats, by
Community structure is defined as follows:
“The spatial organisation, construction and arrangement of the biological elements comprising a
biological assemblage” (eg. Eucalyptus salmonophloia woodland over scattered small shrubs
over dense herbs; structure in a faunal assemblage could refer to trophic structure, eg. dominance
by feeders on detritus as distinct from feeders on live plants).
Definitions of Modification and Destruction of an ecological community:
Modification: “changes to some or all of ecological processes (including abiotic processes such
as hydrology), species composition and community structure as a
naturally or by human intervention.”
Destruction: “modification such that reestablishment of ecological processes, species
composition and community structure within the range of variability exhibited by the original
community is unlikely within the foreseeable future even with positive human intervention.”
Note: Modification and destruction are difficult concepts to quantify, and their application will
be determined by scientific judgement. Examples of modification and total destruction are cited
Modification of ecological processes: The hydrology of Toolibin Lake has been altered by
clearing of the catchment such that death of some of the original flora has occurred due to
dependence on fresh water. The system may be bought back to a semblance of the original state
by redirecting saline runoff and pumping waters of the rising underground watertable away to
restore the hydrological balance. Total destruction of downstream lakes has occurred due to
hydrology being altered to the point that few of the original flora or fauna species are able to
tolerate the level of salinity and/or water logging.
Modification of structure: The understorey of a plant community may be altered by weed
removed from the system the balance may be restored, and the original plant species better able
to compete. Total destruction may occur if additional nutrients continue to be added to the
system causing the understorey to be completely replaced by weed species, and death of
overstorey species due to inability to tolerate high nutrient levels.
Modification of species composition: Pollution may cause alteration of the invertebrate species
inhabitant species. Addition of residual highly toxic substances may cause permanent changes to
water quality, and total destruction of the community.
Threatening processes are defined as follows:
“Any process or activity that threatens to destroy or significantly modify the ecological
community and/or affect the continuing evolutionary processes within any ecological
Examples of some of the continuing threatening processes in Western Australia include: general
introduced animals; competition and displacement of native plants by introduced species;
hydrological changes; inappropriate fire regimes; diseases resulting from introduced
microorganisms; direct human exploitation and disturbance of ecological communities.
Restoration is defined as returning an ecological community to its pre-disturbance or natural
state in terms of abiotic conditions, community structure and species composition.
Rehabilitation is defined as the re-establishment of ecological attributes in a damaged ecological
community although the community will remain modified.
An ecological community that has been adequately searched for but for which no representative
occurrences have been located. The community has been found to be totally destroyed or so
extensively modified throughout its range that no occurrence of it is likely to recover its species
composition and/or structure in the foreseeable future.
An ecological community will be listed as presumed totally destroyed if there are no recent
A) Records within the last 50 years have not been confirmed despite thorough searches of
B) All occurrences recorded within the last 50 years have since been destroyed
An ecological community that has been adequately surveyed and found to have been subject to a
major contraction in area and/or that was originally of limited distribution and is facing severe
modification or destruction throughout its range in the immediate future, or is already severely
degraded throughout its range but capable of being substantially restored or rehabilitated.
An ecological community will be listed as Critically Endangered when it has been adequately
future. This will be determined on the basis of the best available information, by it meeting any
A) The estimated geographic range, and/or total area occupied, and/or number of discrete
i) geographic range, and/or total area occupied and/or number of discrete occurrences
(within approximately 10 years);
ii) modification throughout its range is continuing such that in the immediate future
B) Current distribution is limited, and one or more of the following apply (i, ii or iii):
i) geographic range and/or number of discrete occurrences, and/or area occupied is
highly restricted and the community is currently subject to known threatening
processes which are likely to result in total destruction throughout its range in the
immediate future (within approximately 10 years);
ii) there are very few occurrences, each of which is small and/or isolated and
small and/or isolated and extremely vulnerable to known threatening processes.
C) The ecological community exists only as highly modified occurrences that may be
approximately 10 years).
major contraction in area and/or was originally of limited distribution and is in danger of
significant modification throughout its range or severe modification or destruction over most of
its range in the near future.
An ecological community will be listed as Endangered when it has been adequately surveyed
future. This will be determined on the basis of the best available information by it meeting any
A) The geographic range, and/or total area occupied, and/or number of discrete
i) the estimated geographic range, and/or total area occupied and/or number of
community is likely in the short term future (within approximately 20 years);
ii) modification throughout its range is continuing such that in the short term future
substantially restored or rehabilitated.
short term future (within approximately 20 years);
ii) there are few occurrences, each of which is small and/or isolated and all or most
iii) there may be many occurrences but total area is small and all or most occurrences
C) The ecological community exists only as very modified occurrences that may be
term future (within approximately 20 years).
An ecological community that has been adequately surveyed and is found to be declining and/or
has declined in distribution and/or condition and whose ultimate security has not yet been
of higher threat in the near future if threatening processes continue or begin operating throughout
An ecological community will be listed as Vulnerable when it has been adequately surveyed and
significant modification in the medium to long-term future. This will be determined on the basis
of the best available information by it meeting any one or more of the following criteria (A, B or
A) The ecological community exists largely as modified occurrences that are likely to be
capable of being substantially restored or rehabilitated.
B) The ecological community may already be modified and would be vulnerable to
C) The ecological community may be still widespread but is believed likely to move into
impending threatening processes.
3. DEFINITIONS AND CRITERIA FOR PRIORITY ECOLOGICAL COMMUNITIES
PRIORITY ECOLOGICAL COMMUNITY LIST
Possible threatened ecological communities that do not meet survey criteria or that are not
adequately defined are added to the Priority Ecological Community Lists under Priorities 1, 2
and 3. These three categories are ranked in order of priority for survey and/or definition of the
community, and evaluation of conservation status, so that consideration can be given to their
declaration as threatened ecological communities. Ecological Communities that are adequately
known, and are rare but not threatened or meet criteria for Near Threatened, or that have been
recently removed from the threatened list, are placed in Priority 4. These ecological communities
require regular monitoring. Conservation Dependent ecological communities are placed in
Priority One: Poorly-known ecological communities
Ecological communities with apparently few, small occurrences, all or most not actively
leases) and for which current threats exist. Communities may be included if they are
comparatively well-known from one or more localities but do not meet adequacy of survey
requirements, and/or are not well defined, and appear to be under immediate threat from known
threatening processes across their range.
Priority Two: Poorly-known ecological communities
Communities that are known from few small occurrences, all or most of which are actively
forest, unallocated Crown land, water reserves, etc.) and not under imminent threat of destruction
or degradation. Communities may be included if they are comparatively well known from one or
and appear to be under threat from known threatening processes.
area of which are not under threat of habitat destruction or degradation or:
communities known from a few widespread occurrences, which are either large or within
not under imminent threat, or;
communities made up of large, and/or widespread occurrences, that may or not be
their range from processes such as grazing by domestic and/or feral stock, and
inappropriate fire regimes.
Communities may be included if they are comparatively well known from several localities but
processes exist that could affect them.
Priority Four: Ecological communities that are adequately known, rare but not threatened or
meet criteria for Near Threatened, or that have been recently removed from the threatened list.
These communities require regular monitoring.
been adequately surveyed, or for which sufficient knowledge is available, and that are
considered not currently threatened or in need of special protection, but could be if
present circumstances change. These communities are usually represented on
surveyed and that do not qualify for Conservation Dependent, but that are close to
qualifying for Vulnerable.
during the past five years.
Priority Five: Conservation Dependent ecological communities
Ecological communities that are not threatened but are subject to a specific conservation
within five years.
Under the Wildlife Conservation Act (1950), the Minister for the Environment may declare species
of special protection. Schedules 1 and 2 deal with those that are threatened and those that are
presumed extinct, respectively.
Taxa which have been adequately searched for and are deemed to be in the wild either rare, in
(Schedule 1 under the Wildlife Conservation Act 1950).
Threatened Flora (Schedule 1) are further ranked by the Department according to their level of
CR: Critically Endangered – considered to be facing an extremely high risk of extinction in