The is within the and is the largest being assessed by the Bioregional Assessment Programme. The Galilee occupies diverse environments from the mountains of the Great Dividing Range through a large area of semi-arid and arid inland Australia to the shores of Kati Thanda – Lake Eyre. Key features of the Galilee PAE are its large area, sparse human population density and unpredictable rainfall resulting in natural and human systems driven by resource pulses and boom-bust dynamics. Low human population density results in the natural vegetation being relatively intact. Dominant land use in the PAE is grazing of sheep and cattle on natural pastures (grazing natural vegetation). Other land uses are nature conservation, production forestry (confined to the wetter east-central edge of the PAE) and other minimal use. There is no pasture modification or intensive agricultural production within the PAE. Urban settlement is limited in extent.
As a of its size and diversity, the Galilee PAE contains a large number and diverse range of that span ecological, sociocultural and economic values. As addressed for this Assessment, the subregion has over 4400 assets that comprise over 800,000 individual spatially discrete elements (companion product 1.3 for the Galilee subregion ()). Many of these assets are large in extent; for example, Diamantina National Park, a park in south-west Queensland, has an area of 507,000 ha.
For purposes, a landscape classification was developed to characterise the nature of water dependency among these assets. Specifically, landscape classification is used to characterise the diverse range of into a smaller number of classes for further analysis. It is based on key landscape properties related to patterns in geology, geomorphology, hydrology and ecology. The aim of the landscape classification is to systematically define geographical areas into classes based on similarity in physical and/or biological and hydrological characteristics. The landscape classification includes all natural and human in the PAE. This section describes the methodology and used to arrive at the landscape classification for ecosystems within the Galilee PAE.
The landscape classification developed in this product provides a mechanism by which receptor impact modelling (product 2.7) can be undertaken on a large (>4000) number of assets. The rationale for this process is that a represents a water-dependent ecosystem that has a characteristic hydrological regime. As part of the landscape classification process in this product, the landscape classes are classified into . Landscape groups are sets of landscape classes that share hydrological properties. Subsequent in the BA process, the landscape groups are amalgamated into larger entities to enable receptor impact modelling (product 2.7) to take place. There is no direct interaction between landscape classes and hydrological modelling, either or , in the BA . Not all of the landscape classes defined in this product will be affected by the in the Galilee subregion (refer to Section 2.3.4).
Multiple classification methodologies have been developed to provide consistent and functionally relevant representations of water-dependent ecosystems. An Australian example is the Australian National Aquatic Ecosystem (ANAE) classification framework. The approach outlined here has built on, and integrated, these existing classification systems. It has used predominantly existing classes within data associated with aquatic and (GDEs), remnant vegetation and land use mapping. The landscape classification was carried out on data layers consisting of polygons (e.g. remnant vegetation, wetlands), lines (stream network) and points ( and spring complexes).
18.104.22.168.1.1 Classification and typology of landscape elements (polygons)
The approach taken was developed in close collaboration, and with strong guidance, from experts that have extensive experience with the landscapes of the both in Queensland and SA. These experts have contributed to the development of similar classification systems such as the ANAE (). The classification and typology were developed and refined following a six-step approach that is summarised in Table 3.
The classification is based on five elements derived from the ANAE. The first division is based on topography and is at level 2 (landscape scale) of the ANAE structure. The Galilee PAE is divided into floodplain and non-floodplain areas based on the Land Zones of Queensland (). All polygons that are Land Zone 3 have been classified as ‘floodplain’ with all other land zones classified as ‘non-floodplain’. Land Zone 3 is defined as recent Quaternary alluvial systems or, in simpler terms, alluvial river and creek flats (Queensland Herbarium, ). Land Zone 3 includes inland lakes and associated wave-built lunettes (dunes). The national topographic data from Geoscience Australia () were used to define floodplains in SA as lands that are subject to inundation, marine swamps, swamps or saline coastal flats. This division allows broad classification of the landscape components that might be influenced by flooding regimes that are more likely to support water-dependent biota.
The next division is based on landform and is at ANAE level 3 (system). Polygons were divided into ‘wetland’ and ‘non-wetland’. Wetlands were classified as either ‘estuarine’, ‘lacustrine’, ‘palustrine’ or ‘riverine’ based on the wetland class field in the Queensland wetland mapping (DSITIA, ) and in the SA GDE classification (SA Department for Water, ).
- water source (groundwater/non-groundwater dependent)
- water type (brackish or saline/fresh)
- water availability (permanent/near-permanent (wet greater than 80% of time)/intermittent or ephemeral).
Water availability and water type were inferred from Queensland wetland and mapping . Water type was determined from Queensland wetland mapping for wetlands and from GDE mapping for non-wetlands. Attribution of water source is based on the predominant water source (e.g. if predominantly groundwater, it is classified as such). Combined categories were not used.
In addition to the five elements of the classification derived from the ANAE, an additional variable was used that identified a polygon as either remnant or non-remnant vegetation. This distinction is based on the Queensland remnant Regional Ecosystem (RE) mapping from 2013 (Queensland Herbarium, ). This approach separates relatively intact landscapes from ‘human-modified’ landscapes. This distinction has important for defining where important habitats and biota may occur when considering and their likely distribution.
Table 3 Summary of the seven steps undertaken to develop and refine a classification and then a typology of landscape classes in the Galilee preliminary assessment extent (PAE)
The rule sets applied to the databases to undertake these tasks are summarised in Table 4.
A spatially complete layer of all classed polygons was produced by running a topological overlay of the datasets such that a new polygon dataset was produced, which retained the features of all the input layers. were defined using the five elements from the ANAE structure (Table 5) with their nomenclature reflecting key water-dependency attributes. For example, an area classified as ‘remnant’, ‘non-floodplain’, ‘wetland’, ‘disconnected, ‘saline’ has the landscape class: ‘Non-floodplain disconnected saline wetland, remnant vegetation’. In other words, this area is not on a floodplain and is dependent and associated with a saline wetland.
Table 4 Landscape classification rule sets used for the landscape elements (polygons) in the Queensland portion of the Galilee preliminary assessment extent (PAE)
22.214.171.124.1.2 Classification and typology of the stream network
Streams in the were classified based on their catchment position, water regime and association with (Table 5). Catchment position (i.e. upland versus lowland) is a potential strong influence on stream morphology and flow patterns. Rivers and streams can also receive significant inputs from local and regional and act as sources to support GDEs. Water regime is critical in determining suitable habitat for biota and physical features of the channel and zone.
The stream network had not previously been classified in the Galilee PAE, which meant that the Assessment team completed this part of the landscape classification. The stream network data were based on the v2 cartographic mapping of river channels derived from 1:250,000 topographic maps (Bureau of Meteorology, ). The Geofabric is a purpose-built geographic information system (GIS) that maps Australian rivers and streams and identifies how stream features are hydrologically connected. The water regime of these stream networks was also defined (‘near-permanent’ or ‘temporary’) using the Queensland pre-clearing and remnant ecosystems mapping data (Queensland Herbarium, ). Mapping data of valley bottom flatness (MrVBF) (CSIRO, ) was used to classify streams as either ‘upland’ or ‘lowland’ following methods outlined in . To determine estuarine stream systems, the term ‘tidal’ was added to the source as this identifies areas that are under a tidal influence and hence should be considered estuarine.
Table 5 Landscape classification rule sets used for the stream network polylines
126.96.36.199.1.3 Classification of springs
The logic of the landscape classification rule sets used in the is shown in Figure 19. belonging to the same have the same colour.
188.8.131.52.2.1 Typology of landscape classes
The Assessment team defined a set of that represent the main biophysical and human systems in the . This typology consists of 20 landscape classes derived from polygons, 10 landscape classes from lines (streams) and 1 landscape class from points ().
Landscape classes were classified into 11 . Each landscape group consists of one or more landscape classes. Among polygons, landscape classes were first sorted on the basis of topography (i.e. whether an area is on a floodplain or not). Below the level of topography, the landscape classes were grouped on the basis of water source and whether they are a wetland or non-wetland. Wetlands were divided into and disconnected (reliant on ). The non-wetlands are either terrestrial (i.e. groundwater dependent) or surface water-dependent areas of the landscape. In summary, in each of the two topographical categories (floodplain, non-floodplain), there were potentially four landscape groups. The landscape groups contained landscape classes that were either (i) wetland GDEs, (ii) disconnected (surface water dependent) wetland, (iii) terrestrial (non-wetland) GDEs or (iv) surface water-dependent non-wetlands (referred to in the ‘Floodplain, non-wetland’ landscape group for floodplains and the ‘Dryland’ landscape group for non-floodplains).
For streams, landscape classes were divided into two landscape groups on the basis of whether they were GDE or non-GDE.
The typology developed by the Assessment team includes aspects of existing wetland models such as those developed for Queensland that form part of the Queensland Government’s WetlandInfo website (). Similar wetland models are available for wetlands in other areas of the Galilee . These include models intended to cover the entire Lake Eyre Basin (), NSW including arid regions () and the semi-arid (northern) section of the Murray–Darling Basin (). Each suite of models was consulted in the development of the Bioregional Assessment Programme typology of landscape classes for the Galilee PAE (Table 3, step 1); however, each has strengths and weaknesses and no model covers the entire geographical area or environmental heterogeneity of the Galilee PAE. Therefore, no existing approach was considered suitable to adapt in its entirety for this Assessment. For example, the concordance of the Galilee PAE typology with that from Queensland WetlandInfo is summarised in Table 6.
Table 6 Concordance of landscape classes and landscape groups from the Galilee preliminary assessment extent classification and typology with the Queensland WetlandInfo models
GDE = groundwater-dependent ecosystem
184.108.40.206.2.2 Naming conventions for landscape classes
were named on the basis of the classification systems used for the landscape classification (refer to Table 4 and Table 5). Colloquial terminology was avoided to minimise confusion. Rather, a standard naming convention was adopted. The naming convention for polygon landscape classes (Table 7) is detailed below.
- Floodplain/non-floodplain. Of the 10 landscape classes that are non-floodplain, all but two non-floodplain landscape classes have ‘non-floodplain’ as the first word of the landscape class name. The exceptions are the two landscape classes (which are non-floodplain, non-wetlands) in the ‘Dryland’ . ‘Floodplain’ is used in the name of the six floodplain landscape classes that are ‘disconnected’ ( dependent); these are in the ‘Floodplain, non-wetland’ and ‘Floodplain, disconnected wetland’ landscape groups.
- Wetland/non-wetland. The next word in the name of each landscape class indicates if it is a wetland or not. If it is a wetland, it will either be a (‘wetland GDE’) or surface water-dependent ecosystem (‘disconnected wetland’). If the landscape class is not a wetland, the term ‘terrestrial’ appears for and ‘non-wetland’ for surface water-dependent ecosystems.
- Salinity. Saline disconnected wetlands are indicated as ‘disconnected saline wetland’. Salinity is indicated only for disconnected wetlands.
- Remnant/non-remnant. The broad habitat separation of ‘remnant’ or ‘non-remnant’ is indicated last in the landscape class name. Only the term ‘remnant vegetation’ is included in the name of the landscape class. If this does not appear, then the landscape class is ‘non-remnant vegetation’.
The stream network was defined from a smaller set of criteria. The naming conventions for streams (Table 8) follows this order: ‘temporary’ or ‘near-permanent’, then ‘lowland’, ‘upland’ or ‘estuarine’ and lastly, ‘GDE’ if dependent. .
220.127.116.11.2.3 Area of landscape classes
The typology of included two landscape classes that are non-water dependent (i.e. they support terrestrial vegetation that is not dependent; rather, it relies predominantly on including direct precipitation, flood flows from rainfall and local ). Together, these two landscape classes occupy 68.54% of the Galilee (Figure 20). The predominance of these non-water dependent categories is apparent in the map of landscape classes in the Lagoon Creek and Native Companion Creek, a series of temporary lowland drainages north of Alpha (Figure 21). Here, most of the landscape is in the ‘Dryland, remnant vegetation’ and ‘Dryland’ landscape classes with large areas of the floodplain being in the ‘Floodplain disconnected non-wetland’ and ‘Floodplain disconnected non-wetland, remnant vegetation’ landscape classes.
Of the remaining landscape classes, 26.52% of the area of the PAE consists of floodplain landscape classes, with the remaining 4.87% of the area occupied by non-floodplain, water-dependent landscape classes (Table 7).
Table 7 Typology of landscape classes in the Galilee preliminary assessment extent (PAE) based on polygons with land area and percentage of the PAE
GDE = groundwater-dependent ecosystem
Table 8 Typology of stream network classes in the Galilee preliminary assessment extent (PAE) with total length and percentage of total stream network in the PAE
GDE = groundwater-dependent ecosystem
Table 9 Number of springs in the Galilee preliminary assessment extent
Landscape class number
Inset boxes A to F show the location of Lagoon Creek and Native Companion Creek, north of Alpha, Queensland (Figure 21); Edgbaston Springs complex, north-east of Aramac, Queensland (Figure 22); Carmichael River from near Doongmabulla Springs to its confluence with the Belyando River, Queensland (Figure 23); Thomson River at Longreach, Queensland (Figure 24); Lake Galilee, Queensland (Figure 25); and Cooper Creek and Coongie Lakes, north-west of Innamincka, SA (Figure 26) respectively.
GDE = groundwater-dependent ecosystem
A floodplain can be broadly defined as that area of a landscape that occurs between a river system and the enclosing valley walls and is exposed to inundation or flooding during periods of high (). For the Lake Eyre Basin, floodplains are considered to be alluvial plains that have an average recurrence interval of 50 years or less for channelled or overbank streamflow (). Floodplain and lowland riverine areas derived from Quaternary alluvial deposits are widely distributed across the Galilee and include eight river systems including major catchments such as the Burdekin, Fitzroy, Flinders, Diamantina and Cooper river basins. The floodplains of the south-westerly flowing river systems are extremely wide; for example, in some areas the floodplain of the Cooper Creek exceeds 60 km.
‘Floodplain, non-wetland’ landscape group
Floodplains within the Galilee consist of a significant area that is classified as ‘non-wetland’. These areas of the floodplain support terrestrial vegetation that is not dependent; rather it relies predominantly on including direct precipitation, flood flows from rainfall and local . This is widespread across the Galilee PAE (Figure 20 and Figure 21).
GDE = groundwater-dependent ecosystem
‘Floodplain, wetland GDE’ landscape group
Wetland occupy a small part of the ; 0.81% of the area is covered by polygons. This includes palustrine and lacustrine wetlands around discharge . A map of the in the vicinity of Edgbaston Springs north-east of Aramac (Figure 22) illustrates the spatial distribution of wetland GDEs within the eastern portion of the PAE. Similarly, wetland GDEs occur along Carmichael River, near Doongmabulla Springs (Figure 23) in the north-west portion of the landscape.
Wetland GDEs are of extremely high importance in terms of biodiversity values. The biodiversity values for this landscape group are covered in detail under the ‘Springs’ landscape group.
GDE = groundwater-dependent ecosystem
‘Floodplain, terrestrial GDE’ landscape group
The ‘Floodplain, terrestrial GDE’ contains that have a subsurface reliance on . Landscape classes in the ‘Floodplain, terrestrial GDE’ landscape group occupy a significant portion of the Galilee (12.94%) and are widespread throughout the PAE. Particular concentrations occur close to major river systems in the south and south-west (Figure 20).
Terrestrial typically consist of terrestrial vegetation of various types (open forest, woodland, shrubland, grassland) that require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements. The plants in these landscape classes are dependent on the subsurface presence of groundwater, which is accessed via their roots at depth. Examples of terrestrial GDEs in the PAE include vegetation such as river red gum (Eucalyptus camaldulensis) open forest and coolibah (Eucalyptus coolabah) woodland.
Floodplain terrestrial GDEs in the Galilee PAE differ on the basis of water availability. The majority access intermittent subsurface groundwater.
Landscapes dominated by terrestrial GDEs are shown in the vicinity of Carmichael River and the Belyando River (Figure 23) in the east of the PAE and in the vicinity of the Thomson River (Figure 24), an inland draining system south-east of Longreach. .
Terrestrial GDEs on floodplains possibly support three threatened ecological communities listed in the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). These threatened ecological communities are:
- Brigalow (Acacia harpophylla dominant and co-dominant)
- Natural Grasslands of the Queensland Central Highlands and the northern Fitzroy Basin
- Weeping Myall Woodlands.
Groundwater dependency of these communities is yet to be established but they have been included based on the expectation that where these communities occupy floodplains interception of groundwater will occur.
Terrestrial GDEs on floodplains are likely to provide habitat for two EPBC Act-listed threatened species that occur within the Galilee PAE. These species are:
- squatter pigeon (southern) (Geophaps scripta scripta), vulnerable
- waxy cabbage palm (Livistona lanuginosa), vulnerable.
The waxy cabbage palm is part of the riparian vegetation along river channels and on floodplains on alluvial duplex soils in a small area of the Burdekin river basin that includes Doongmabulla on Carmichael River. It relies on subsurface availability of groundwater (Pettit and Dowe, 2004;). The squatter pigeon feeds and breeds in woodland that is both groundwater and dependent.
GDE = groundwater-dependent ecosystem
‘Floodplain, disconnected wetland’ landscape group
The ‘Floodplain, disconnected wetland’ includes all floodplain wetland that depend predominantly on such as flood flows from rainfall events, direct precipitation and local . These wetlands are usually separated from the underlying by an ; if seepage does occur it is not the main source of water. Because most of the Galilee is within regions of low and unpredictable rainfall, most of these wetlands are temporary. This landscape group includes both saline (here referring to both brackish and saline, >3000 mg/L total dissolved solids) and freshwater landscape classes. Landforms included are lacustrine and palustrine. Saline disconnected wetlands include lakes and swamps. Saline swamps commonly form on the fringing dunes of saline claypans. These saline systems are closed hydrologically – a lack of regular freshwater flushing can lead to very high salinity.
A landscape dominated by the ‘Floodplain, disconnected wetland’ landscape group is Lake Galilee (Figure 25), a terminal wetland fed by about 20 temporary lowland streams in the east of the PAE. The area consists of a mixture of saline and freshwater disconnected wetlands. Another floodplain landscape that is dominated by disconnected wetlands is Cooper Creek in the vicinity of Coongie Lakes (Figure 26), in the arid zone of SA. This dominance of disconnected wetland in the lower reaches of the Cooper system contrasts with the terrestrial that dominate upstream at the Thomson River immediately south-east of Longreach (Figure 24) and the easterly flowing Carmichael River and Belyando River (Figure 23).
Remnant vegetation associated with disconnected wetlands includes woodland of river red gum, coolibah or river cooba (Acacia stenophylla); and shrubland of lignum (Muehlenbeckia florulenta) and northern bluebush (Chenopodium auricomum). Chenopod shrublands are common on some saline disconnected wetlands and include samphire (Halosarcia spp.), saltbushes and bluebushes.
Waterholes are included in this landscape group. Waterholes are of considerable importance because they continue to hold water once flow in river channels ceases. Thus waterholes act as refuges for aquatic biota when natural fragmentation occurs during dry periods and play a key role in sustaining assemblage dynamics (Arthington et al., 2010; ). Waterholes may or may not interact with groundwater depending on the level of substrate and on depth to groundwater. Most waterholes in the Diamantina and Cooper river systems are not groundwater dependent (). Although surface water-dependent waterholes lose water through evaporation, suspended clays that settle out after flow events form a bottom seal that minimises seepage losses.
This landscape group supports an EPBC Act-listed threatened ecological community, ‘Coolibah – Black Box Woodlands of the Darling Riverine Plains and the Brigalow Belt South Bioregions’ (). The threatened ecological community is classified as surface water dependent and occurs on floodplains in the south-east portion of the .
The ‘Floodplain, disconnected wetland’ landscape group is likely to provide habitat for four EPBC Act-listed threatened species that occur within the Galilee PAE. These species are:
- Australian painted snipe (Rostratula australis), endangered
- ornamental snake (Denisonia maculata), vulnerable
- squatter pigeon (southern), vulnerable
- star finch (eastern) (Neochmia ruficauda ruficauda), endangered.
The Australian painted snipe depends on shallow freshwater wetlands, including floodplain lakes and swamps, in which to feed and breed. The squatter pigeon feeds and breeds in woodland that is both surface water and groundwater dependent and depends on a daily uptake of water — most of which is likely to come from disconnected wetlands on floodplains. The star finch occupies swamps and other wetlands on floodplains. The ornamental snake occupies river channels and adjacent floodplains with cracking clay soils and feeds on frogs in and around wetlands.
A further four are water dependent but do not occur on floodplains (Table 7). The land zones that support these landscape groups include clay plains, loamy and sandy plains, inland dunefields, and fine-grained and coarse-grained sedimentary rocks. The occurrence of these non-floodplain land zones is variable across the . Extensive areas of duricrusts (Land Zone 7) occur throughout the Galilee PAE with concentrations along the eastern margins and in the south-west corner. In the north-east and central eastern parts of the PAE the geology mainly comprises intrusive igneous rock and sedimentary rock. In contrast, inland dunefields (Land Zone 6) are confined to the extreme south-west of the PAE.
‘Dryland’ landscape group
Drylands are those areas of the landscape that are not on the floodplain and are not wetlands. Water comes from rainfall and local and its availability is unpredictable. Most of the Galilee is semi-arid or arid, with a mean annual rainfall of less than 500 mm (companion product 1.1 for the Galilee subregion (Evans et al., 2014, Figure 11)). It is only the eastern margin of the PAE that receives greater than 500 mm of rainfall on average annually. Rainfall within the PAE and throughout arid and semi-arid northern Australia is highly unpredictable (van Etten, 2010) and occurs in discrete pulses. As a , land systems such as drylands, which depend on rainfall and local runoff for water availability, experience irruptive pulses in primary productivity and support a biota that undergoes boom-bust population dynamics.
Most of the Galilee PAE is dryland and most of this area supports remnant vegetation. A wide range of vegetation types occur including Mitchell grass (Astrebla) tussock grassland, spinifex (Triodia) hummock grassland, Eucalyptus open forest and woodland, and Acacia (including Mulga and Brigalow) open woodland and shrubland.
The ‘Dryland, remnant vegetation’ provides habitat for EPBC Act-listed threatened ecological communities including ‘Brigalow (Acacia harpophylla dominant and co-dominant)’ and ‘Weeping Myall Woodlands’.
‘Non-floodplain, wetland GDE’ landscape group
The two in the ‘Non-floodplain, wetland GDE’ occupy a very small area of the . Non-floodplain wetland occur where sedimentary layers outcrop at or near the surface especially where there are sandstone ranges.
In the central and western regions of the Galilee PAE, sand dunefields (sand ridges) are an important source of , which supports non-floodplain wetland GDEs. These dunefields can store groundwater in local, intermediate or regional groundwater flow systems and also in perched formed by layers of relatively impermeable clay-dominated material. Palustrine, lacustrine and riverine wetlands on the edge of inland sand dunefields may be present because of the surface expression of this groundwater.
‘Non-floodplain, terrestrial GDE’ landscape group
The details of in the ‘Non-floodplain, terrestrial GDE’ are similar to the landscape classes in the ‘Floodplain, terrestrial GDE’ landscape group; however, the former landscape group occupies a smaller area of the (3.39%) (Table 7). Terrestrial are typically terrestrial vegetation of various types (open-forest, woodland, shrubland, grassland) that require access to on a permanent or intermittent basis to meet all or some of their water requirements. In the case of non-floodplain environments, terrestrial GDEs tend to be on loamy or sandy plains or inland sand dunefields (sand ridges), which are largely composed of unconsolidated sand deposited by aeolian processes (wind). These landscape classes are dependent on the subsurface presence of groundwater, which is accessed via their roots at depth. On inland sand dunefields, groundwater is available from unconsolidated sedimentary from which terrestrial vegetation typically accesses water through the capillary zone above the .
‘Non-floodplain, disconnected wetland’ landscape group
The ‘Non-floodplain disconnected wetland’ includes all non-floodplain that depend on such as flood flows from rainfall events. Landforms included are lacustrine and palustrine. Also included are riverine elements such as waterholes. This landscape group includes saline/brackish and freshwater wetlands with water availability being usually non-permanent or near-permanent, with rare examples of permanency. Landscape classes in the ‘Non-floodplain, disconnected wetland’ landscape group make up 1.43% of the , with the most common landscape class being ‘Non-floodplain disconnected saline wetland’ (1.25% of the PAE) (Table 7).
Rockholes are a type of wetland only present in the ‘Non-floodplain, disconnected wetland’ landscape group. Rockholes are natural hollows in rocky landscapes that form by fracturing and weathering of rock and which store water from local (). Typically, rockholes occur in sandstone and granite ranges within the Galilee PAE. As with other wetlands in this landscape group, most rockholes are non-permanent; however, a small number are known to be permanent, replenished by small rainfall events ().
Gilgai is another type of non-floodplain, disconnected wetland. Gilgais occur within the clay plains land zone and consist of shrink-swell and cracking clay soils that form depressions. Gilgai microrelief occurs when the layers of clay soil shrink and swell during alternate drying and wetting cycles. Gilgai depressions fill with water during and after rain resulting in a landscape containing several shallow wetlands.
Landscapes in the ‘Non-floodplain, disconnected wetland’ landscape group potentially provide habitat for four EPBC Act-listed threatened species that occur within the Galilee PAE. These species are:
- Australian painted snipe, endangered
- squatter pigeon (southern), vulnerable
- star finch (eastern), endangered
- Lawrencia buchananensis, vulnerable.
Lawrencia buchananensis grows only on the fringes of Lake Buchanan and Lake Constant. The species may be surface water dependent but this is not known for sure.
The streams within the are divided into two : ‘Streams, GDE’ and ‘Streams, non-GDE’ (Table 8).
‘Streams, GDE’ landscape group
Riverine occur in both lowland and upland streams. The most common in this group is ‘Temporary, lowland GDE stream’. Stream GDEs may occur in streams with gaining or variable gaining/losing . These streams receive from upward leakage from sandstone aquifers such as the Hooray Sandstone, Clematis-Warang Sandstone and Ronlow beds (companion product 1.1 for the Galilee subregion (Evans et al., 2014, p. 113)). This – connectivity is highest where Galilee Basin strata outcrop along the eastern margin of the and involve rivers such as the Belyando River.
‘Streams, non-GDE’ landscape group
Streams in the ‘Streams, non-GDE’ occur in both upland and lowland areas. The low and unpredictable rainfall across most of the Galilee has resulted in this landscape group being dominated by streams that are temporary. Specifically, the ‘Temporary, lowland stream’ makes up 83.12% of the total stream network, whereas the ‘Near-permanent, lowland stream’ landscape class is only 0.03%.
‘Springs’ landscape group
The ‘Springs’ (Table 9) includes both discharge and recharge springs. Discharge springs occur where escapes to the surface under hydrostatic pressure from cracks and faults in the confining bedrock. Discharge spring wetlands in the Galilee occur on recently deposited alluvia and fine-grained sedimentary rocks (shales). The area of discharge spring wetlands is generally small, mostly less than 0.05 ha, but with a small number of more than 1 ha wetlands (). Vegetation varies from site to site depending on moisture, but generally supports a ground layer of grasses, sedges and/or a mat of herbs.
This landscape group supports a threatened ecological community listed in the EPBC Act, ‘The community of native species dependent on natural discharge of groundwater from the Great Artesian Basin’. This threatened ecological community occurs in parts of NSW, elsewhere in Queensland and within the Galilee PAE in Queensland and SA (). It includes three species of EPBC Act-listed threatened freshwater fish: the redfin blue eye (Scaturiginichthys vermeilipinnis), Edgbaston goby (Chlamydogobius squamigenus) and Elizabeth Springs goby (Chlamydogobius micropterus). The redfin blue eye is endangered and the Edgbaston goby is vulnerable. Both occur, often together, in springs within the Barcaldine supergroup at Edgbaston Station and, in the case of the Edgbaston goby, Crossmoor Station on the Thomson River. The range of the redfin blue eye is four springs – approximately 0.3 ha, whereas the Edgbaston Goby occupies 11 springs. The Elizabeth Springs goby is endangered and occurs within the Galilee PAE at the Elizabeth Springs complex and Spring Creek ().
The endangered mat-forming herb, salt pipewort (Eriocaulon carsonii), also occurs within discharge springs of the Galilee PAE in Queensland and SA. Another endangered herb, blue devil (Eryngium fontanum), is confined to two spring complexes within this landscape group ().
Recharge springs occur in upland areas within the PAE. An example is recharge springs from sandstone . These springs and associated wetlands are dependent on groundwater and occur where sediments that form an aquifer are outcropping ().
18.104.22.168.3.5 Modified landscapes
As mentioned in Section 22.214.171.124, very little of the includes modified landscapes. In this respect, the differs from most of the other being assessed by the Bioregional Assessment Programme. The PAE does not include any dryland cropping or horticulture, irrigated cropping or horticulture, grazing of modified pastures or intensive horticulture or animal production. The main on water-dependent ecosystems from human activity is the placement of to provide water at the surface for livestock. Bores rely on and in the past have had a significant negative impact on within the PAE (Fensham and Fairfax, 2003; ). Urban settlement is very limited in extent and the towns that exist have a low population size. These towns rely on groundwater and via bores and river offtakes.
Product Finalisation date
- 2.3.1 Methods
- 2.3.2 Summary of key system components, processes and interactions
- 2.3.3 Ecosystems
- 2.3.4 Baseline and coal resource development pathway
- 2.3.5 Conceptual model of causal pathways
- Currency of scientific results
- Contributors to the Technical Programme
- About this technical product