Describing the

Barmah Forest Ramsar Site ecological character description

A Victorian Government initiative A Victorian Government initiative Published by the Victorian Government Department of Sustainability and Environment Melbourne, October 2008 © The State of Victoria Department of Sustainability and Environment (DSE) 2008 This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968 . Authorised by the Victorian Government, 8 Nicholson Street, East Melbourne. ISBN 978-1-74208-770-2 For more information contact the DSE Customer Service Centre 136 186 This Barmah Forest Ramsar Site ecological character description was prepared using the ‘Framework for describing the ecological character of Ramsar ’, and formed part B of this report which was published by DSE, in January 2005.

This report was prepared with the financial support of the Australian Government under the Natural Heritage Trust

Acknowledgments The Barmah Ramsar Site ecological character description developed by the Department of Sustainability and Environment with the assistance of a project steering committee. Project steering committee Janet Holmes and Julia Reed (Victorian Government Department of Sustainability and Environment), Sarah Young and Lisa Evans (Australian Government Department of Environment and Heritage), Wayne Tennant and Keith Ward (Goulburn Broken Catchment Management Authority) and Bruce Wehner (Parks Victoria): Lisa Lowe of Sinclair Knight Mertz analysed flow data for the project. Flow data Flow data for the Murray River at Tocumwal was provided by Murray-Darling Basin Commission and River Murray . The Department of Sustainability and Environment acknowledges that neither the Murray-Darling Basin Commission nor River Murray Water has any responsibility in terms of the accuracy, interpretation or use of the data. Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.

Cover page: Ibis colony at Barmah Forest. DSE.

TABLE OF CONTENTS

1. Ecological character description details ...... 1 2. services for the Barmah Forest Ramsar Site...... 2 3. Ecosystem services to be used as the basis for the ecological character description...... 3 4. Description of ecosystem services and identification of related components...... 3 4.1 control ...... 5 4.2 recharge...... 6 4.3 Supports all four of the freshwater types in Victoria...... 7 4.4 Supports depleted wetland types...... 8 4.5 Supports representative vegetation communities ...... 8 4.6 Supports a large variety of communities...... 10 4.7 Supports the largest Red Gum forest in (together with Millewa Forest in NSW) ...... 11 4.8 Part of a large natural floodplain system (together with Millewa Forest in NSW) ...... 12 4.9 Supports the most extensive area of Moira Grass plains in Victoria ...... 12 4.10 Provides for waterbirds ...... 13 4.11 Supports a high diversity of ...... 14 4.12 Supports threatened species ...... 15 4.13 Provides one of Victoria’s largest waterfowl breeding areas, particularly for Australian White Ibis and Straw- necked Ibis ...... 15 4.14 Supports an of waterbirds ...... 17 4.15 Summary of components and processes that maintain ecosystem services ...... 18 5. Specified components ...... 20 5.1 Connectivity of surface : operation of regulators ...... 20 5.2 Capacity of the Millewa Choke and the Barmah Choke...... 21 5.3 Groundwater levels ...... 21 5.4 Hydrogeology ...... 21 5.5 Wetland depth...... 22 5.6.1 Hydrology - flooding requirements for wetlands ...... 22 5.6.2 Hydrology - flooding requirements for vegetation associations...... 23 5.6.3 Hydrology - flooding requirements for waterbird breeding and abundance...... 26 5.6.4 Hydrology - flooding requirements to provide drought refuge for waterbirds...... 28 5.6.5 Hydrology – to support a large natural floodplain ...... 28 5.7 for breeding waterbirds...... 29 6. Conclusions ...... 29 References ...... 31 Appendix 1. Threatened species of flora and fauna...... 33 Appendix 2 . Breeding records for colonially nesting waterbirds 1961-1982 ...... 36

Description of the ecological character of Barmah Forest Ramsar Site

1. Ecological character description details DescribingTable 1 provides introductory details the regarding the ecological character description for the Barmah Forest Ramsar Site.

Table 1. Details of the ecological character description for Barmah Forest Ramsar Site.

Site name Barmah Forest Location The Barmah Forest Ramsar site is located on the Murray River floodplain in the State of Victoria, approximately 225 kilometers north of Melbourne. Area 29,516 hectares (Source: RAMSAR_100 layer in DSE GIS Corporate Library) Date of listing as a Ramsar site 15 December 1982 Date for which the description The description is for the Ramsar Site at the of listing in 1982. of ecological character applies Management authorities Parks Victoria and the Department of Sustainability and Environment Status of description This is the first description of the ecological character of Barmah Forest Ramsar Site. Name of compiler Janet Holmes Senior Policy Officer and Natural Division Department of Sustainability and Environment East Melbourne. Victoria. 3002. Email: [email protected] Date of compilation August 2004 Reference for Ramsar Barmah Forest Ramsar Information Sheet, May 1999 . Department of Information Sheet Sustainability and Environment website: http://www.dse.vic.gov.au/DSE/nrence.nsf/LinkView/97E95CB32619 DC20CA2572A00011BEF13D4353ED718B354CCA2572A00012817A Reference for management Department of Sustainability and Environment (2003a) Barmah Forest plan Ramsar Site Strategic Management Plan . Department of Sustainability and Environment. East Melbourne.

Describing the ecological character of Barmah Forest Ramsar Site 1 A Victorian Government initiative 2. Ecosystem services for the Barmah Forest Ramsar Site The ecosystem services for the Barmah Forest Ramsar Site are listed in Table 2. The primary source of the information for each ecosystem service is indicated.

Table 2. Ecosystem services for the Barmah Forest Ramsar Site.

Ecosystem service Source Timber production 1 Cattle grazing 1 Apiculture 1 Flood control 1 Groundwater recharge 1 Recreational fishing and bait collecting 1 Hunting of waterfowl and pest 1 Picnics, outings, touring, cycling, horse riding and bushwalking 1 Nature observation 1 Scenic values 1 Aboriginal cultural heritage 1 Historic relics and reflecting events associated with European settlement 1 Educational values 1 Research into forest and floodplain and hydrology 1 Organic carbon storage 1 Nutrient cycling 1 High productivity 3 Supports all four of the freshwater wetland types in Victoria 1 Supports depleted wetland types in Victoria 1 Supports vegetation communities representative of the Murray Fans bioregion 2 Supports a large variety of communities 4 Supports a high diversity of species 1 Supports threatened species 1 Part of a large natural floodplain system (together with the adjoining Millewa Forest in NSW) 1 Supports the largest Red Gum forest in Australia (together with the adjoining Millewa Forest in 1 NSW) Supports the most extensive area of Moira Grass plains in Victoria 1 Supports migratory waterbirds listed under the Commonwealth Environment Protection and 1 Biodiversity Conservation Act 1999 Supports an abundance of waterbirds 1 Provides one of Victoria’s largest waterfowl breeding areas, particularly for Australian White 1 Ibis and Straw-necked Ibis Provides drought refuge for waterbirds 1

Sources 1. Ramsar site management plan: (DSE, 2003a) 2. Chesterfield et al. (1984), DSE (2003b) 3. Directory: Environment Australia (2001) 4. RIS: Barmah Forest Ramsar Information Sheet. (DSE,1999)

Knowledge gaps relating to other ecosystem services • The role of Barmah forest in nutrient and retention and maintenance for the River Murray is uncertain and limited information is available. A small-scale project has been done on sediment by Thoms and Walker (1990). • It has not been documented or tested as to whether Barmah Forest stabilizes local conditions. • Very little information exists on the role of Barmah Forest in the maintenance and production of native so the values for native fish are not known. • There is no specific information about the role of birds at Barmah in controlling pests on neighbouring farmland. Local farmers’ value role of ibis and some duck species in controlling pests of irrigated pastures.

Describing the ecological character of Barmah Forest Ramsar Site 2 3. Ecosystem services to be used as the basis for the ecological character description Barmah Forest was listed as meeting the following of the pre-1999 Ramsar criteria: 1a, 2b, 3a, 3b, 3c (Barmah Forest Ramsar Information Sheet, May 1999). These equate to the current Ramsar criteria: 1, 3, 5, 6. • Criterion 1 : A wetland should be considered internationally important if it contains a representative, rare, or unique example of a natural or near-natural wetland type found within the appropriate biogeographic region. • Criterion 3 : A wetland should be considered internationally important if it supports populations of and/or species important for maintaining the biological diversity of a particular biogeographic region. • Criterion 5 : A wetland should be considered internationally important if it regularly supports 20,000 or more waterbirds. • Criterion 6 : A wetland should be considered internationally important if it regularly supports 1% of the individuals in a of one species or subspecies of waterbird. The ecosystem services listed in Table 3 will be used as the basis for the ecological character description for Barmah Forest Ramsar Site. They include services that relate to the above criteria and three additional services that relate to Ramsar criteria 2 and 4, for which the site is not listed. Table 3. Ecosystem services to be used for the ecological character description of Barmah Forest Ramsar Site.

Ecosystem services that relate to the Ramsar criteria for listing Barmah Forest as a Ramsar Site Ecosystem service Ramsar criteria Flood control 1 Groundwater recharge 1 Supports all four of the freshwater wetland types in Victoria 1 Part of a large natural floodplain system (together with the adjoining Millewa Forest in NSW) 1 Supports the largest Red Gum forest in Australia (together with the adjoining Millewa Forest 1, 3 in NSW) Supports vegetation communities representative of the Murray Fans bioregion 3 Supports a large variety of communities 3 Supports a high diversity of species 3 Supports the most extensive area of Moira Grass plains in Victoria 3 Provides one of Victoria’s largest waterfowl breeding areas, particularly for Australian White 3, 6 Ibis and Straw-necked Ibis Supports an abundance of waterbirds 5 Ecosystem services that relate to the Ramsar criteria 2 and 4 (not criteria for which the site is listed) Supports threatened species 2 Provides drought refuge for waterbirds 4 Supports depleted wetland types 2

4. Description of ecosystem services and identification of related components This section describes, in specific terms, each of the ecosystem services selected as the basis for the ecological character description. It also identifies the ecological components and processes that are critical in supporting each service and indicates which components and processes will be further specified in the ecological character description. For ecosystem services that are not subject to a high degree of variability, the ecosystem services are specified as they were at or as close as possible to the time of listing in 1982, depending on the availability of data. For services which are subject to a high degree of natural variation and for which hydrology is critical (waterbird drought refuge, abundance and breeding), the baseline description for the ecosystem services is based on the state of the services as they were in the period 1961-1982

Describing the ecological character of Barmah Forest Ramsar Site 3 inclusive. This period has been selected because it was a period over which the level of regulation of the Murray River was reasonably stable leading up to the listing of the Ramsar site in 1982. The Murray River is the source of floodwaters in Barmah Forest. The Murray River has been subjected to increasing levels of regulation and diversion of water for agriculture since Hume Dam was first completed in 1934. The extension to Hume Dam was completed in 1961. The level of regulation remained the same until Dartmouth Dam was commissioned in 1979. The construction of Dartmouth Dam did not change the flood regime for at least ten years because there was a period of above average rainfall in the catchment which produced (Leitch, 1988). However there was a gradual increase in diversions during the period 1961-1982. Flows in the Murray River for the period of record are shown in Figure 1. The period 1961-1982 also encompassed a wide range of natural variation with both and major floods occurring. It was also the period in which waterbird values began to be better documented for Barmah Forest. An explanation is provided of how each component or process maintains the service. Components that are to be further specified in the ecological character description are identified. Ecological processes are not specified as there is very little information on the relationship between the ecosystem services and ecological processes. Unless otherwise stated, data for flows in the Murray provided in this description are for flows measured at Tocumwal.

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Figure 1. Flows for the Murray River at Tocumwal 1908-2004. Four time periods are coloured separately: 1. 1908-1934 (blue): from the commencement of records to the completion of Hume Dam; 2. 1935-1960 (red): from the completion of Hume Dam until its enlargement; 3. 1961-1982 (green): from the enlargement of Hume Dam to the listing of the Ramsar site; and 4. 1983-2004 (black): from the listing of the Ramsar site to 2004.

Describing the ecological character of Barmah Forest Ramsar Site 4 4.1 Flood control The ecosystem service is the natural control and amelioration of flooding in the Murray River downstream of Barmah Forest. Barmah Forest begins to flood at moderately low river flows (Leitch, 1988). Flood peaks are reduced in the Murray River downstream of Barmah Forest as floodwaters, restricted by the capacity of the Millewa and Barmah Chokes in the Murray River channel, flow out across the Barmah-Millewa floodplain or are diverted to the Edwards River. Floodwaters in Barmah Forest that do not infiltrate the , replenish deeper wetlands or are not used by vegetation, drain back into the Murray downstream of the Barmah Choke at Barmah Lake. This delays the flood but prolongs the period of higher flows, albeit at attenuated levels, downstream. The service has not been quantified for this description because it is unlikely to change unless the capacity of the Barmah or Millewa Choke changes. The method for determining change in the level of flood control provided by the forest would involve using existing Murray River flow data to compare flood characteristics directly upstream (at Tocumwal or Yarrawonga) and downstream (at Barmah or Torrumbarry) of Barmah Forest. Recommended comparisons are for the peak and duration of a range of flood sizes upstream and downstream using spell analysis, or the frequency of floods of a certain size upstream and downstream using flow exceedance curves for the winter/spring period. Floods from tributaries to the Murray between Barmah Forest and the gauging station would need to be subtracted. A change in ecological character for this service would be signalled by a permanent change in the peak and duration of floods downstream of Barmah Forest for floods of a given size.

Component or How the component or process maintains the service process Capacity of The restricted capacity of Millewa Choke and Barmah Choke in the Murray River Millewa Choke channel causes the Barmah Forest to flood when the daily flow exceeds approximately and Barmah 11,000 ML/day. Flooding of Barmah Forest, together with that in Millewa Forest and Choke any diversions to the Edwards System, reduces and delays flood peaks downstream. This component is specified in Section 5. Floodplain The topography of the floodplain is an important factor in determining the volume of topography water that is retained on the floodplain and the volume that drains back into the river downstream of Barmah Choke. Ground levels in the forest fall ten metres from east to west. The gradient is uniform over the majority of the floodplain but flattens significantly in the west (Maunsell, 1992). Detailed information about floodplain topography was not available in 1982 and the relationships between topography and water storage or movement are only known in general terms. This component is not further specified. Vegetation Vegetation cover influences the rate of flood recession by slowing floodwaters. It also cover influences the amount of water returned to the river, as use water directly. Gross changes in vegetation cover (for example, due to clearing) will not take place in the foreseeable future, as the forest is managed as a natural system for conservation and/or sustainable use under legislation and policy. Vegetation communities are described in Section 4.5. More detailed information is not available on vegetation cover and this component is not specified. Soil type Soil type determines the capacity of soil to take up moisture during floods. The level of soil moisture influences the volume of water that drains back into the river as the flood recedes. on the floodplain are relatively uniform and consist of grey clays and grey sands (Rees, 2000). There are localised areas of sandy soils. Soil type is unlikely to undergo short or medium term changes and is not specified further in the description of ecological character. Hydrogeology Some floodwater will infiltrate to the . However there is no specific information on the rate and volume of aquifer recharge and, therefore, this is not specified in the description of ecological character. However, a description of the hydrogeology is provided in Section 5.

Describing the ecological character of Barmah Forest Ramsar Site 5 4.2 Groundwater recharge There is evidence suggesting that the shallow aquifer (the Upper Shepparton Formation) underlying Barmah Forest is recharged during floods (SKM, unpub.). Recharge of the groundwater when the forest is not flooded appears to be localised with surface water features not influencing the groundwater to a great degree (SKM, unpub.). When water levels are high in the Murray River there is potential for the river to recharge the adjacent groundwater system, particularly in the vicinity of the Barmah Choke where surface waters back up in the river. Conversely, if water levels are low there may be potential for groundwater discharge to the river (SKM, unpub.). The relative importance of other factors in recharging the Upper Shepparton Formation in Barmah Forest is understood in broad terms but has not been quantified. Such factors include potential for lateral movement of water in the Upper Shepparton Formation towards the forest from the groundwater mound under the Murray Valley Area (MVIA) and vertical recharge of the Upper Shepparton Formation from deeper regional if pressure in those aquifers exceeds those in the Upper Shepparton Formation. Groundwater pumping from the deep aquifer is undertaken and reduces pressure (SKM, unpub.). No data is available to determine the volume and rate of recharge directly. However, groundwater monitoring has been conducted since 1984. Bores have been established in and adjacent to the forest at 98 locations (SKM, unpub.). A 1984-1987 study by the Rural Water Commission (1988) indicated that the water tables in Barmah Forest were generally low (11-14 metres below the surface) except adjacent to the river where a perched was present along the Murray River. Pressure levels in deep aquifers were higher than those in shallow water tables in some parts of the forest indicating that deep seepage into the underlying aquifers was no longer occurring and it was predicted that this may result in a rise in the water table level and salt accumulation in the Upper Shepparton Formation. The adjacent MVIA had a water table generally within two metres of the surface. The mound under the MVIA extended to the edge of the Forest. In Barmah Forest, water levels in the Upper Shepparton Formation were in a state of equilibrium where inputs to groundwater were balanced by transpiration. SKM (unpub.) reports on reviews of groundwater monitoring in 1988, 1989, 1994, 1995 and 1999 as well as on the results of monitoring data up to May 2003. SKM (unpub.) reported an increasing trend in groundwater levels in the Upper Shepparton Formation in the period 1978- 1994/95, followed by a decreasing trend from 1994/95 to 2003. In August 2002, groundwater levels were generally between 8 and 16 metres below the surface in Barmah Forest. The critical components in maintaining the level of groundwater recharge are indicated below. However, there is no quantitative information on the relationship between groundwater recharge and the components that maintain the service. Components such as hydrogeology and size of the floodplain are unlikely to change. Vegetation cover is unlikely to influence the rate of recharge significantly as most recharge occurs when excess waters are available during floods. However, transpiration by Red Gums is thought to be a factor in maintaining lower groundwater levels in the Upper Shepparton Formation in Barmah Forest relative to those in the aquifer in adjacent cleared dryland and irrigation areas (SKM, unpub). Roberts and Marston (2000) cite Bren (unpub.) and Bacon et al. (1993) as stating that Red Gums have some roots (‘sinkers’) that penetrate more than ten metres into the sub soil to reach sandy aquifers. A significant change in Red Gum distribution is unlikely. It is suggested that it is more appropriate to continue to monitor groundwater tables in the forest and adjacent areas than to monitor groundwater recharge or the components that maintain this service. A change in the ecological character for this service would be signalled by a significant change in the depth of the water table. SKM (unpub) state that if groundwater levels were to rise within five metres of the surface, management of groundwater would be required.

Describing the ecological character of Barmah Forest Ramsar Site 6

Component or How the component or process maintains the service process Hydrology Floodwaters are the major source of water for recharging the Upper Shepparton Formation aquifer in Barmah Forest. Therefore, the frequency, magnitude and duration of flooding are some of the main factors likely to influence groundwater levels in the forest. The direct relationship between the flood regime and recharge is unknown and therefore, hydrology is not specified in relation to this service. Hydrogeology The Upper Shepparton Formation generally consist of lower permeability clay and clayey silts with lenses of high permeability sands (SKM, in prep.). Such lenses facilitate recharge of the aquifer during floods. A description of the hydrogeology of the forest and surrounding areas is provided in Section 5.

4.3 Supports all four of the freshwater wetland types in Victoria Barmah Forest supports 26,958 hectares of freshwater wetlands representing all of the four freshwater wetland categories. This represents 91.3% of the Ramsar site. Freshwater wetlands in Barmah Forest constitute 8.7% of the total area of natural freshwater wetlands in Victoria. Wetland types were classified and mapped in Barmah Forest in 1993 and 1994 (Martin O’Brien, pers. comm.) using the Victorian system developed by Corrick and Norman (1980) based on water depth, duration of inundation after filling and . This system identifies eight categories, including four categories for freshwater wetlands. The data is stored on the DSE Corporate GIS layer WETLAND_1994. The extent and category of wetlands is considered not to have changed significantly since the Ramsar site was listed in 1982. Therefore, data from this layer is used to specify the ecosystem service. The area of wetland categories in Barmah Forest is shown in Table 4. Their distribution can be obtained from the GIS layer. A change in the ecological character of the Ramsar site with regard to this service would be signalled by a change in the distribution or decrease in the area of the wetland categories. Each wetland category is further divided into subcategories based largely on dominant vegetation. The subcategories information is not used in the description of ecological character because dominant vegetation may have changed between the date of listing in 1982 and the time the wetlands were classified and mapped in 1993/94. The condition of the wetlands has not been assessed using a standardised method. When such a method is available, regular assessment of wetland condition is recommended.

Table 4. Area of wetland categories in Barmah Forest Ramsar Site and Victoria. (Source: WETLAND_1994 DSE GIS Corporate Library).

Wetland category Area in Barmah Area of remaining Proportion of the area Forest ramsar Site natural wetlands in of remaining natural Victoria wetlands in Victoria Freshwater Meadow 18,499 115,066 16.1 Shallow Freshwater 7,285 52,639 13.8 Deep 879 54,175 1.6 Permanent Open Freshwater 295 86,679 0.3 All wetlands 26,958 308,559 8.7

Component or How the component or process maintains the service process Wetland depth The topography of the floodplain determines the potential depth of inundation of wetland areas by floodwaters. Depth also influences duration of inundation with deep wetlands taking longer to dry than shallow ones after filling. Depth classes and period of inundation are specified for each wetland type in Section 5. Hydrology If there was to be a permanent loss of large floods, wetlands that are only inundated in such floods would cease to function as wetlands. The frequency of large floods is specified in Section 5.

Describing the ecological character of Barmah Forest Ramsar Site 7

Component or How the component or process maintains the service process Salinity Wetlands are classed as saline if salinity exceeds 3,000 mg/L throughout the year (DCE and Office of the Environment 1992). Wetlands in the Barmah Forest are filled from from the Murray River. Salinity levels are unlikely to exceed 3000 mg/l in this reach of the River. In 1994/95, mean salinity was 57 µS/cm (approximately 2040 mg/L) downstream of Yarrawonga Weir (Crabb, 1997). SKM (unpub.) state that there is no immediate threat of high groundwater levels in the forest and any consequent salinity problems. This component is not specified further.

4.4 Supports depleted wetland types Freshwater meadows and shallow freshwater are two of the most depleted wetland categories in Victoria with only 57% of the original area of freshwater meadows and 40% of the original area of shallow freshwater marshes remaining (NRE 1997). Barmah Forest supports significant proportions of the remaining wetlands of each type: 16% of the remaining natural freshwater meadows and 13.8% of the remaining shallow freshwater marshes (Table 4). A change in the ecological character of the Ramsar site with regard to this service would be signalled by a decrease in the area of freshwater meadows or shallow freshwater marshes. The components that maintain the depleted wetland types are the same as those that support the four freshwater wetland types.

4.5 Supports representative vegetation communities The vegetation communities at Barmah Forest are representative of wetland vegetation communities in the Murray Fans bioregion in which Barmah Forest Ramsar Site is located. The following description of the Murray Fans Bioregion has been adapted from DSE (2003b). The Murray Fans bioregion is located on the Victorian edge of the Murray River and covers 421,000 hectares of the northern riverine plain. It stretches from Yarrawonga in the east, downstream to Boundary Bend in the north-west. The Murray Fans bioregion is a floodplain of alluvial fan-shaped deposits along the Murray River typified by Barmah and Gunbower forests. This floodplain displays numerous ox-bows and meander scrolls, as well as many source- bordering dunes (typically supporting drier, highly localised vegetation formations). Flanking the floodplain is a terrace of better-drained riverine plain, sometimes also including wind- blown dunes. The natural vegetation of the floodplain consists largely of seasonally flooded River Red Gum communities along the major streams, anabranches and billabongs, with Black Box/Lignum woodlands on the less regularly watered fringes of the and watercourses and Black Box Chenopod woodlands or saltbush communities on sites which do not normally receive floodwaters. Woodlands on the better-drained riverine plain and dunes are dominated by River Red Gum and box eucalypt species, Buloke and cypress-pine species, or some mix of these, with a shrub layer often dominated by wattle or saltbush species. Vegetation description and mapping of Barmah Forest was based on ground survey in 1979 (Chesterfield et al. 1984, Chesterfield, 1986). This is the best benchmark for describing the distribution of the vegetation at the time of Ramsar listing in 1982. The area mapped by Chesterfield et al. coincides almost exactly with the Barmah Forest Ramsar Site. The only difference is that Chesterfield et al. map a narrow strip of land approximately 20 hectares in area along the Murray River adjacent to the Yielima freehold block which is not part of the Ramsar site. The area and proportion of the forest occupied by each association is provided in Table 5. A map of the distribution is available in Chesterfield et al. (1984) and Chesterfield (1986).

Describing the ecological character of Barmah Forest Ramsar Site 8 Table 5. Vegetation associations of Barmah Forest. Sources: Chesterfield et al. 1984, Chesterfield, 1986, Ward (1991)* and Leitch (1988)**. The area of vegetation associations has been calculated using percentages from Ward (1991) and the total area of the forest (29,516 hectares) from the GIS RAMSAR_100 layer in the DSE GIS Corporate Library. Ward attributes figures for the percentage of forest area occupied by each vegetation association to Chesterfield (1986), although Chesterfield (1986) and Chesterfield et al. (1984) do not provide percentage estimates for every vegetation association and, for some associations, provide slightly different percentages. The percentages and areas provided should be treated as approximate.

Structural Overstorey Height Understorey dominant species % of Area type dominant species (m) Barmah (ha) Forest* Rushland Giant Rush <3.0 1.8 531 Juncus ingens Grassland Moira Grass <0.5 5.2 1535 Pseudoraphis spinescens Open Red Gum 33 Moira Grass 13.8 4073 Forest – Eucalyptus Woodland camaldulensis Open Red Gum 31 Disturbed areas of wallaby grasses now 1.9 561 Forest – dominated by numerous introductions Woodland Open Red Gum 28 Terete Culm-sedge (Hollow Sedge) Carex 21.7 6405 Forest – tereticaulis in association with Woodland Wallaby Grass Amphibromus spp. And Warrego Summer Grass Setaria jubiflora Open Red Gum 28 Terete Culm-sedge 10.8 3188 Forest – Woodland Open Red Gum 28 Common Spike-rush Eleocharis acuta in 5.7 1682 Forest – association & mosaic with Swamp Woodland Wallaby Grass & Warrego Summer Grass Open Red Gum 28 Warrego Summer Grass 19.4 5726 Forest – Woodland Open Red Gum 25 Wallaby grasses 2.0 590 Forest - Woodland Open Red Gum 22 Swamp Wallaby and Brown-back Wallaby 9.6 2834 Forest - Grass Austrodanthonia duttoniana in Woodland association and mosaic with Common Spike-rush Open Red Gum 1-15** Moira Grass and Common Spike-rush 4.3 1269 Forest - Woodland Woodland Yellow Box E. 20 Gold-dust Wattle Acacia acinacea , 3.2 945 -Open melliodora , Grey wallaby-grasses and numerous Woodland Box E. microcarpa introductions Woodland Black Box E. 18 Wallaby Grasses, Saloop Einadia hastata , 0.4 118 -Open largiflorens Prickly Salwort Salsola tragus and Woodland numerous introductions

Current vegetation mapping of ecological vegetation classes (EVCs) in Barmah Forest has indicated that the structural types and dominant overstorey species are likely to have been mapped accurately by Chesterfield et al. However, there is less certainty regarding the accuracy of the understorey mapping (Keith Ward pers. comm.). For understorey species, it may not be valid to compare the mapping by Chesterfield et al. to that for the EVCs when they are completed. In monitoring for change, allowance must be made for the precision and accuracy of the original mapping and any differences in the method being used for comparison. A change in ecological character for this service since the time of listing as a Ramsar site would be signalled by a change in the distribution or area of dominant overstorey species mapped by

Describing the ecological character of Barmah Forest Ramsar Site 9 Chesterfield (1986). To monitor to detect change in ecological character in relation to vegetation communities, it would be useful to relate EVCs to Chesterfield’s vegetation associations. The condition of vegetation communities in Barmah Forest is also important in determining ecological change. The effects on vegetation condition from a history of timber harvesting, grazing by introduced livestock and invasion by exotic species are documented in general terms (for example, in DSE, 2003a). A quantitative benchmark for vegetation condition is not available for 1982 when the forest was listed as a Ramsar site. A ‘habitat hectares’ method was recently developed for assessing vegetation condition (Parkes et al., 2003). Regular assessment of vegetation condition is recommended using the Victorian habitat hectares method to detect future changes.

Component or How the component or process maintains the service process Floodplain The topography of the floodplain is one of the factors that determine flora topography distribution. ‘Small differences in elevation can influence vegetation by determining flood frequency and duration’ (Chesterfield et al. 1984). Detailed information about floodplain topography was not available in 1982, so this component is not specified. A digital elevation model was recently completed for Barmah Forest which provides a sub-metre representation of the floodplain surface which is accurate to within 15 centimetres. This could be used as the baseline for monitoring any future changes in floodplain topography and exploring the relationship between vegetation distribution and topography. Hydrology The flooding regime is another important determinant of the distribution of vegetation associations. The seasonality, frequency, duration and magnitude of floods are all important in determining plant distribution. Each of the overstorey dominants in the vegetation associations mapped by Chesterfield et al. (1984) has different flooding requirements which are specified in Section 5. Soil type Soil type is less important in determining vegetation distribution than topography and flooding regime. Soils on the floodplain are relatively uniform and consist of grey clays and grey sands (Rees, 2000). There are localised areas of sandy soils which support different understorey vegetation because of better drainage properties (Keith Ward pers. comm.). Yellow Box is restricted to uncommon sandy soils above flood level (Chesterfield et al., 1984). Soil type is unlikely to undergo short or medium term changes and is not specified further in the description of ecological character. Natural Connectivity within the wetland is important in determining which parts of the forest connectivity of are inundated during particular floods. The pattern of surface water connectivity at a surface waters broad-scale within the forest is unlikely to have changed significantly since the forest was listed as a Ramsar site. Effluent creeks which leave the Murray River and flow through the Barmah Forest are mapped in detail on large-scale topographic maps of the area. Natural connectivity is likely to continue to undergo local changes due to sedimentation and erosion processes (Maunsell 1992). Some creeks within the forest were blocked in the past to facilitate access for timber harvesting. Such obstructions would have disrupted connectivity at the local scale. These have now largely been removed. No detailed information is available to set a baseline for 1982. Natural connectivity of surface waters is not further specified. Connectivity In the 1930s and 1940s, regulators were installed on several of the distributary creeks (regulators) that flow into Barmah Forest at the point where they leave the Murray River. Regulators are used to exclude unseasonal summer flows at flows up to 11,000 ML/day. The exclusion of summer flooding is important in maintaining the balance between the distribution of communities dominated by Moira Grass, Red Gum and Giant Rush (Ward, 1991). Regulators are also used for controlled watering of parts of the forest when flows surplus to irrigation needs or environmental flows are available. The operation of regulators is specified in Section 5.

4.6 Supports a large variety of communities Barmah Forest supports 13 vegetation associations (Table 5). A change in this service would be signalled by a loss of a vegetation community or the substantial decrease in extent or decline in condition of a community.

Describing the ecological character of Barmah Forest Ramsar Site 10 The components that maintain the representative vegetation communities are the same as those that support this service.

4.7 Supports the largest Red Gum forest in Australia (together with Millewa Forest in NSW) The Barmah Forest and the adjacent Millewa Forest in NSW cover about 68,000 hectares and are dominated by Red Gum E. camaldulensis . The Barmah Forest Ramsar site covers 29,517 hectares (DSE GIS Corporate Library RAMSAR_100 layer). Chesterfield (1986) identified 89.2% of the forest as dominated by Red Gum vegetation associations. This is an area of 26,328 hectares based on the total area of the Ramsar site from the GIS layer and the data in Table 5. The distribution and area of the vegetation associations dominated by Red Gum in this mapping differs somewhat from the distribution and area of wetlands dominated by Red Gum mapped by Corrick in 1993/1994 and recorded on the WETLAND_1994 GIS layer in the DSE GIS Corporate Library. It is unknown if this represents change as the two surveys used different methods. Chesterfield used ground survey methods while 1993/1994 wetland mapping used a variety of sources including air photographs, forestry maps and ground truthing (Andrew Corrick pers. comm.). To detect change in ecological character for this service, allowance must be made for the precision and accuracy of the mapping by Chesterfield et al. (1984), the 1993/94 wetland mapping and the any differences in the method being used for comparison. The condition of the Red Gum forest is also important. Condition could be measured using the habitat hectares method (Parkes et al. 2003). A change in ecological character for this service would be signalled by a decrease in area or decline in condition of the vegetation associations dominated by Red Gum. However, invasion by Red Gum of vegetation associations with other dominants, such as Moira Grass, would also be considered an adverse change.

Component or How the component or process maintains the service process Floodplain The topography of the floodplain is one of the factors that determine Red Gum topography distribution. Topography influences the potential soil moisture regime and potential depth of inundation during floods. It also influences duration of inundation with deep areas taking longer to dry than shallow ones. Detailed information about floodplain topography was not available in 1982, so this component is not specified. The recently completed digital elevation model for Barmah Forest could be used as the baseline for monitoring any future changes in floodplain topography. Hydrology The seasonality, frequency, duration and magnitude of floods are all important in determining the distribution of Red Gum associations. Leitch (1988) indicates that flooding frequency and duration is important in determining Red Gum height and understorey distribution. He indicates that Red Gum Forest on the drier parts of the floodplain would become stressed if flood frequency and duration declines significantly from natural conditions. The flooding requirements for Red Gum are specified in Section 5. Connectivity of Connectivity within the wetland is important in determining which parts of the forest surface waters are inundated during particular floods. The pattern of surface water connectivity at a broad-scale within the forest is unlikely to have changed significantly since the forest was listed as a Ramsar site and is not further specified. The operation of regulators (as described in Section 5) is unlikely to reduce Red Gum area or distribution because moderate and large floods are not excluded. Groundwater Survival of Red Gums during extended dry periods is influenced by the availability of levels groundwater (Roberts and Marston, 2000). In some situations Red Gums may be largely dependent on groundwater (Roberts and Marston, 2000). Chesterfield (1986) quotes Dexter (1978) as stating that highly productive Red Gum forest adjacent to the Murray River is considered to be watered by groundwater. Groundwater levels are specified in Section 5.

Describing the ecological character of Barmah Forest Ramsar Site 11 4.8 Part of a large natural floodplain system (together with Millewa Forest in NSW) In geomorphological terms, the floodplain is defined by the topography which determines the maximum extent of flooding. In ecological terms, the extent of the floodplain is defined by the extent of flood-dependent communities. This was 28,376 hectares in Barmah Forest when surveyed in 1979 (Chesterfield 1986). Flood-dependent communities include all the vegetation associations in Table 2 except the association dominated by Yellow Box and Grey Box. The naturalness of the floodplain relates to the fact that the floodplain supports indigenous vegetation communities representative of the Murray Fans bioregion, as outlined in Section 4.5. A change in this ecosystem service would be signalled by a decrease in the extent of floodplain communities, particularly invasion by Yellow Box-Grey Box associations on the driest parts of the floodplain.

Component or How the component or process maintains the service process Floodplain The topography of the floodplain determines the maximum extent of flooding. A topography reduction in the size of the floodplain is unlikely to occur except through very long- term geomorphological processes. A levee along the southern perimeter of Barmah Forest confines floodwaters to Barmah Forest and protects adjacent private property from flooding. Changes to the levee or further construction of floodplain levees has not occurred and is unlikely to be undertaken (Keith Ward pers. comm.) and, therefore, the physical size of the floodplain is unlikely to change. Hydrology The flood regime, especially the duration and the frequency of large floods, are important in determining the distribution of flood-dependent communities. If there was to be a permanent loss of large floods, the area of flood dependent communities would decrease and species that are not flood tolerant would encroach onto previously flooded areas. However, Leitch (1988) states that Red Gum forest is unlikely to transform into communities dominated by Yellow Box and Grey Box forest because regulation has had little effect on the frequency of large floods. Any temporary encroachment of non-tolerant species would be unlikely to survive large floods. The frequency of large floods is specified in Section 5.

4.9 Supports the most extensive area of Moira Grass plains in Victoria Moira Grass dominated 5.2% (1,535 hectares) of the Barmah Forest Ramsar site in 1979 (Table 2). Chesterfield (1986) states that the percentage of the forest dominated by Moira Grass in 1930 was 13.5%. Leitch (1988) attributes the decline to river regulation which commenced when Hume Dam was completed in 1934. A change in ecological character for this service would be signalled by a continued decrease in area of the Moira Grass plain accompanied by the encroachment of Giant Rush and regeneration of Red Gum in the areas that Chesterfield et al. (1984) mapped as being dominated by Moira Grass.

Component or How the component or process maintains the service process Floodplain The topography of the floodplain determines potential water depth which influences topography Moira Grass distribution. Moira Grass requires a water depth of at least 0.5 metres and tolerates depth of water up to two metres (Ward 1991). A depth of at least 0.5 metres is required to kill Red Gum seedlings that have established in areas dominated by Moira Grass and to prevent premature nodal rooting of Moira Grass in the substrate. Detailed information about floodplain topography was not available in 1982, so this component is not specified. A digital elevation model was recently completed for Barmah Forest which provides a sub-metre representation of the floodplain surface which is accurate to within 15 centimetres. This could be used as the baseline for monitoring any future changes in depth for areas dominated by Moira Grass.

Describing the ecological character of Barmah Forest Ramsar Site 12

Component or How the component or process maintains the service process Sedimentation Sedimentation has the potential to decrease depth, favouring Red Gum establishment in areas dominated by Moira Grass. Ward (1991) cites a study by Thoms and Walker (1990) which concluded that there was a relatively high rate of sedimentation in the Moira Grass community at War Plain (2.18 cm/year). However, Maunsell (1992) questioned the conclusion of Thoms and Walker and suggested that sedimentation rates are possibly between 1.6 - 3.8 mm/year. Given the uncertainty regarding sedimentation, this component is not specified. Hydrology The seasonality and duration of floods are important in determining Moira Grass distribution. Prolonged flooding into summer can favour the growth of Upright Milfoil which tends to precipitate sediment from floodwaters at a higher rate than Moira Grass because of its greater hydraulic roughness. The flooding requirements of Moira Grass are specified in Section 5. Competition Competition from both Red Gum and Giant Rush are considered to have resulted in the decrease in the area dominated by Moira Grass. Of the 4,050 hectares of Moira Grass plains present in 1930, Chesterfield (1986) estimated that 1200 hectares had been lost to Red Gum regeneration and 1200 hectares to Giant Rush. Successful competition by Moira Grass in relation to these species relates to favourable depth and hydrological regime. These are specified rather than competition for which there are no detailed quantitative data.

4.10 Provides drought refuge for waterbirds In the years leading up to the listing of the Ramsar site in 1982, droughts affected south eastern Australia in 1963-68, 1972-73 and 1982-1983 (BoM undated). Records of waterbirds in the Victorian Wildlife Atlas (DSE 2004a) show reasonable numbers of waterbirds in the forest and some breeding during the 1963-1968 and 1972-73 droughts (Table 6). Records in October 1982 show very low counts for waterbird species present (DSE 2004b). Table 6. Records of 100 or more waterbirds during drought periods. Source DSE (2004b).

Date of count Common Name Scientific Name Count 25/08/1963 Grey Teal Anas gracilis 500 25/08/1963 Pacific Black Duck Anas superciliosa 400 5/10/1963 Grey Teal Anas gracilis 200 1/01/1964 Little Pied Cormorant Phalacrocorax melanoleucos 250 (breeding) 10/12/1964 Black Swan Cygnus atratus 300 2/02/1965 Australian Wood Duck Chenonetta jubata 150 1/01/1973 Little Pied Cormorant Phalacrocorax melanoleucos 200 (breeding)

It is not possible to establish a benchmark for the use of Barmah Forest by waterbirds as a drought refuge because systematic waterbird surveys during periods of drought are not available. Also droughts are not readily defined and are variable in their physical extent, duration and severity. However, the potential of Barmah Forest to provide drought refuge for waterbirds is related to the fact that, due to the topography of Barmah Forest, flooding commences at relatively low river flows which means the forest floods frequently. To detect a change in this service it will be necessary to monitor the frequency of flooding.

Component or How the component or process maintains the service process Capacity of The restricted capacity of Millewa Choke and Barmah Choke in the Murray River Millewa Choke channel causes the Barmah Forest to flood when the daily flow exceeds approximately and Barmah 11,000 ML per day. This component is specified in Section 5. Choke Hydrology The potential for Barmah Forest to flood at low river levels increases the chance of waterbird habitat being available during droughts. A change would be signalled by a decrease in the frequency of floods as compared to the period 1961-1982. This is specified in Section 5.

Describing the ecological character of Barmah Forest Ramsar Site 13

Component or How the component or process maintains the service process Connectivity of The operation of regulators on the effluent creeks that distribute water into the forest surface water from the Murray River is aimed at preventing loss of regulated flow into the forest, (regulators) which can occur at low river flows of 6,000 ML/day (Maunsell, 1992). Regulators are generally closed to exclude floodwaters from the forest at flows up to about 11,000 ML/day during the irrigation . Before regulators were installed, the likelihood of flooding during droughts would have been higher. However, regulators also prevent unseasonable summer and autumn flooding in the forest. Regulators were present before the Ramsar site was listed and their general operation has not changed. This component is not further specified in relation to this service.

4.11 Supports a high diversity of species As of August 2004, 381 indigenous flora species and 221 indigenous vertebrate fauna species had been recorded on the Victorian Flora Information System (DSE 2004b) and the Victorian Wildlife Atlas (DSE 2004a) for Barmah Forest Ramsar Site. Loyn et al. (2002) reports an additional 58 fauna species but these may include records from adjacent areas outside the forest. The current number of species recorded at Barmah Forest from the Flora Information System and Wildlife Atlas is used as the benchmark for species diversity for the Ramsar site. Current records have been used because the data for species diversity up until the end of 1982, when Barmah Forest was listed as a Ramsar site, appear not to be comprehensive. This is attributed to the fact that many fewer records were added to the databases before 1982 than after, rather than to an influx of species, which is unlikely. Before 1982, only 113 flora species and 134 vertebrate fauna species had been recorded. Current records for fauna in the Wildlife Atlas include those from reasonably comprehensive fauna surveys of the forest between 1977 and 2000, particularly those described by Loyn et al. (2002). Flora data are likely to be reasonably comprehensive as well with 474 observations recorded from the forest up until August 2004. Chesterfield et al. (1984) lists 325 native flora species for observations between 1977 and 1980 but these were not all added to the Flora Information System. A change in the ecological character for this ecosystem service would be signalled by a decrease in the number of species from the current numbers. Data on abundance would also be useful in future monitoring to detect decline in abundance for individual species. To detect change in species diversity, monitoring of species would need to be done systematically in representative and related to events, particularly flooding. The recommended for fauna survey are late spring and early summer and/or winter (Loyn pers comm.)

Component or How the component or process maintains the service process Floodplain The topography of the floodplain is one of the factors that determine flora habitat. topography ‘Small differences in elevation can influence vegetation by determining flood frequency and duration’ (Chesterfield et al. 1984). Topography is also a factor in providing fauna habitat related to the potential depth and duration of floodwaters. Detailed information about floodplain topography was not available in 1982, so this component is not specified. Hydrology The flooding regime is another determinant of habitat, for flora and fauna species. The seasonality, frequency, duration and magnitude of floods are all important in determining species diversity. Flooding determines water depth and period of inundation which influences plant establishment and survival and provides physical habitat for aquatic fauna species. Flooding promotes primary productivity and provides triggers for flora and fauna reproduction. Flooding requirements for the whole suite of species found in Barmah Forest are not known. For the purposes of this ecological character description, it is assumed that the flooding regime required to support the species that dominate the vegetation associations identified by Chesterfield (1986) will support overall species diversity. The flooding requirements for these species are specified in Section 5.

Describing the ecological character of Barmah Forest Ramsar Site 14

Component or How the component or process maintains the service process Soil type Soil type influences flora species distribution. Soils on the floodplain are relatively uniform and consist of grey clays and grey sands (Rees, 2000). There are localised areas of sandy soils. Soil type is unlikely to undergo short or medium term changes and, therefore, any changes in the composition of vegetation are unlikely to relate to changes in soil type. This component is not further specified in the description of ecological character. Vegetation Barmah Forest supports natural vegetation communities (Table 2). Large intact natural cover areas have the capacity to support larger number of species than small fragmented areas. Gross changes in vegetation cover and fragmentation (for example, due to clearing) will not take place in the foreseeable future, as the forest is managed as a natural system for conservation and/or sustainable use under legislation and policy. This component is not specified.

4.12 Supports threatened species The strategic management plan for Barmah Forest Ramsar Site (DSE 2003a) lists 32 threatened flora species and 49 threatened fauna species (Appendix 1). Species recorded up until 2003 are used as the benchmark for this ecosystem service. Data on the Victorian Flora Information System (DSE, 2004b) and the Victorian Wildlife Atlas (DSE, 2004a), from where this threatened species list was derived, do not record several of these species up until the end of 1982 when the forest was listed as a Ramsar site. This is attributed to many fewer flora and fauna records being added to the databases before 1982 rather than an influx of threatened species or previously common species having since become threatened, which is unlikely. All these species will need to continue to be represented to maintain ecological character with regard to this ecosystem service. Threatened species could be monitored as part of general flora and fauna monitoring programs as suggested in Section 4.11 or through targeted monitoring for threatened species in line with the Victorian Flora and Fauna Guarantee Act 1988 action statements or programs specified in recovery plans. The components that maintain the high diversity of species are likely to be the same as those that support this service in general terms. Additional components for individual species are not specified.

4.13 Provides one of Victoria’s largest waterfowl breeding areas, particularly for Australian White Ibis and Straw-necked Ibis Chesterfield et al. (1984) consider that the main significance of Barmah Forest for waterbirds is as a breeding area, especially for colonially nesting species such as ibis. This ecosystem service is specified in relation to colonially nesting species. Records of breeding for all waterbird species is not comprehensive. However, it can be assumed that conditions that lead to breeding by colonially nesting waterbirds are likely to lead to breeding by most other waterbird species. For colonially nesting species in Victoria, an extensive literature review was undertaken in 1993 to identify all existing records and place them on a DSE Wetlands Database and the Victorian Wildlife Atlas (DSE, 2004a). All breeding records where a date (or month), location and species could be ascertained were added to the DSE Wetlands Database and Wildlife Atlas (Martin O’Brien pers. comm.). In some cases, actual counts were not available. Chesterfield et al. (1984) provides additional reports of breeding that were not added to the Wildlife Atlas because of lack of data on time or species. Notably, Chesterfield et al. (1984) cited reports of very high numbers of breeding ibis (mainly Straw-necked Ibis) in 1974/75. Table 7 indicates the years in which the 15 colonially nesting species were recorded breeding in the period 1961-1982. Full records from the Victorian Wildlife Atlas and Chesterfield et al. (1984) are provided in Appendix 2. All records of breeding by colonially nesting waterbirds where months or dates were recorded were in spring or summer, except for records of breeding egrets in March 1967.

Describing the ecological character of Barmah Forest Ramsar Site 15 Table 7. Years when breeding of colonially nesting waterbird species in Barmah Forest has been reported. See Appendix 2 for a full list of breeding records, including sources of information. No breeding of these species was reported in 1961-1963, 1965, 1971-1972, 1975-1977 and 1980-1982.

Species 1964 1966 1967 1968 1969 1970 1973 1974 1978 1979 Australian White Ibis Y Y Y Y Straw-necked Ibis Y Y Y Y Egrets Y Y Great Egret Y Y Y Intermediate Egret Y Y Little Egret Y Y Great Cormorant Y Y Y Y Y Little Black Cormorant Y Y Y Y Little Pied Cormorant Y Y Y Y Y Y Y Y Pied Cormorant Y Nankeen Night Heron Y Y Y Royal Spoonbill Y Whiskered Tern Y Y Y White-necked Heron Y Y Y Yellow-billed Spoonbill Y Y

For Australian White Ibis and Straw-necked Ibis, records may not be comprehensive. Chesterfield et al. (1984) report that ‘ibis have apparently bred in every year when the forest was flooded in spring’. Loyn et al. (2002) reports that hundreds of thousands bred in the major floods of 1973-1975 and, in subsequent years, hundreds or thousands of pairs have bred. Recorded counts for ibis are provided in Appendix 2. Egrets have not been recorded breeding in Barmah Forest since 1969. Breeding has continued to be recorded in the adjacent Millewa Forest in New South Wales into the 1990s for all three egret species (Leslie, 2001). Barmah Forest is listed under Ramsar Criterion 6 because it regularly supports 1% of the population of Australian White Ibis and Straw-necked Ibis. (2002) estimate the Australian population of Australian White Ibis as <70,000 and Straw-necked Ibis as 500,000. For the period 1961-1982, Barmah Forest is known to have supported 1% of the population of Australia White Ibis in 1973, 1978/79, 1979/80 and possibly in 1974/75 (Appendix 2). Barmah Forest supported more than 1% of the population of Straw-necked Ibis in 1974/75 (Appendix 2). It is possible 1% of the population of both species may have been supported in other years during this period when large floods occurred (for example, 1964, 1970 and 1981) but were not recorded. A change in ecological character in relation to the breeding of colonially nesting waterbirds would be signalled by a significant reduction in the frequency of successful breeding events for any of the species listed in Table 7. It would also be signalled by a significant reduction (for example, by an order of magnitude) in the number of each species of ibis, egrets or cormorant regularly breeding when compared with the numbers recorded in Appendix 2. The Ramsar site should continue to support at least 1% of the national population of Australian White Ibis and Straw-necked Ibis to continue to meet Ramsar Criterion 6. In assessing ecological change, it would be important to take into account natural long term climatic variation. The population of the species over its range in south-eastern Australia and the availability of alternative breeding options in south-eastern Australia may also determine whether or not breeding occurs in Barmah Forest, even if flood conditions appear suitable. These factors should also be taken into account when assessing change.

Describing the ecological character of Barmah Forest Ramsar Site 16

Component or How the component or process maintains the service process Hydrology The seasonality, magnitude and duration of floods are all important in influencing successful breeding of colonially nesting waterbirds. Frequency of suitable floods is important to assist in maintaining populations. The breeding requirements for colonially nesting waterbirds are specified in Section 5. Connectivity of Regulators can be used to direct flows to specific wetlands to maintain waterbird surface water breeding events when flooding required to sustain breeding activity does not occur. (regulators) The operation of regulators is further specified in Section 5. Habitat The presence of suitable habitat is essential to allow breeding to take place. This includes suitable nest sites and foraging areas. The requirements for individual species are specified in Section 5. Productivity The level of productivity is important in ensuring that there is sufficient food available for waterbirds to lay and rear young. No specific data is available for productivity in relation to waterbird breeding at Barmah Forest so this process is not specified. However, litter inputs, organic matter decay, nutrient release and population levels are closely linked to the drying and flooding cycle on floodplains (Leslie, 2001).

4.14 Supports an abundance of waterbirds There is insufficient recorded waterbird abundance data for Barmah Forest for 1961-1982 to establish a baseline for waterbird abundance. This relates to the lack of comprehensive surveys and systematic recording of data, except for the work of Chesterfield et al. (1984) between 1977 and 1980. Also, waterbird surveys are difficult when the forest is flooded. Chesterfield et al. reported results of waterbird counts in Barmah Forest between August 1977 and November 1980. The results of these counts are summarised in Table 8. Breeding counts for colonially nesting waterbirds in the period 1961 to 1982 inclusive are presented in Appendix 2. However, a search of the Victorian Wildlife Atlas (DSE, 2004a) for the same period revealed only five additional records of counts over 100 for four additional waterbird species. There are no waterbird records on the Wildlife Atlas for the major floods in 1973-1975. Despite the lack of systematic data, Barmah Forest Ramsar Site is considered an important area for waterbirds given the extensive area of forested wetland which is regularly flooded providing both feeding and breeding habitat (Chesterfield et al., 1984). An anecdotal report of 100,000 or more breeding Straw-necked Ibis and Australian White Ibis in the floods of 1974 and 1975 is provided by Chesterfield et al. (1984). The Ramsar Information Sheet for the NSW Central Murray State Forests Ramsar Site,( State Forests of NSW & NSW National Parks and Wildlife Service, unpub.), which includes Millewa Forest adjacent to Barmah, indicates that more than 10,000 pairs of breeding ibis were recorded in Barmah Forest in 2000/01 and that the waterbird census for the Barmah-Millewa Forest would have exceeded 100,000 waterbirds. Barmah Forest is listed under Ramsar Criterion 5 because it regularly supports 20,000 or more waterbirds. Conditions that lead to breeding by ibis are likely to lead to waterbird abundance generally. Floods of the magnitude that led to high numbers of ibis in 1974/75 and 2000/01 occurred on six occasions in the period 1961-1982 and five occasions since 1982 (Figure 1). Therefore, it is considered very likely that Barmah Forest continues to meet Ramsar criterion 5. A survey of waterbirds during each flood (for example, by air) is recommended to establish a useful long-term data set for this ecosystem service. Conditions that lead to breeding by colonially nesting waterbirds are likely to promote waterbird abundance generally. Therefore, the components of hydrology and productivity that maintain breeding waterbirds (Section 4.13) are considered to be very similar to those that would be required to support this service.

Describing the ecological character of Barmah Forest Ramsar Site 17 Table 8 . Summary of waterbird counts recorded between 1977 and 1980 in Barmah Forest (Chesterfield et al., 1984).

Nov Apr Aug Oct- Jan- Jul Aug Oct Dec- Aug 1977 1978 1978 Nov Feb 1979 1979 1979 Jan 1980 1978 1979 1979 Barmah Lake 416 425 >548 320 >6829 122 1135 126 1174 31 and War Plain Rest of 165 119 >750 >868 >1819 542 253 3758 761 53 Barmah Forest Total 581 544 >129 >118 >864 664 1388 3884 1935 84 waterbird 8 8 8 count for Barmah Forest Total no. of 16 16 20 22 25 21 20 27 24 9 species for Barmah Forest

4.15 Summary of components and processes that maintain ecosystem services A summary of the components and processes that are critical in maintaining the ecosystem services selected as the basis for the ecological character description is presented in Table 9.

Describing the ecological character of Barmah Forest Ramsar Site 18 Table 9. Components and processes critical in maintaining the ecosystem services selected for the ecological description of Barmah Forest Ramsar Site (shaded boxes). Those that are further specified in the ecological character description are indicated as follows: Yes: specified, No: not specified.

Component/ Process

Ecosystem service Capacity of Millewa Millewa of Capacity Chokes Barmah and Hydrogeology depth Wetland Hydrology Connectivity (regulators) levels Groundwater Habitat cover Vegetation type Soil Salinity topography Floodplain Productivity (natural) Connectivity Sedimentation Competition Flood control Yes Yes No No No

Groundwater Yes No recharge

Supports all four Yes Yes No of the freshwater wetland types in Victoria Supports depleted Yes Yes No wetland types

Supports Yes Yes No No No vegetation communities representative of the Murray Fans bioregion Supports a large Yes Yes No No No variety of communities Supports the Yes Yes No No largest Red Gum forest in Australia Part of a large Yes No natural floodplain system Supports the most Yes No No No extensive area of Moira Grass plains in Victoria Provides drought Yes Yes No refuge for waterbirds Supports a high Yes No No No diversity of species Supports Yes No No No threatened species

Provides one of Yes Yes Yes No Victoria’s largest waterfowl breeding areas Supports an Yes No abundance of waterbirds

Describing the ecological character of Barmah Forest Ramsar Site 19 5. Specified components This section provides descriptions of the components that are specified for the ecological character description of Barmah Forest Ramsar Site.

5.1 Connectivity of surface waters: operation of regulators Services to which the component relates • Supports representative vegetation communities • Supports a large variety of communities • Provides one of Victoria’s largest waterfowl breeding areas, particularly for Australian White Ibis and Straw-necked Ibis Regulators were installed on several creeks in the 1930s and 1940s where they leave the Murray River. The original procedures for regulator operation, developed in the 1950s and 1960s, were aimed at preventing loss of regulated flow into the forest, which can occur at low river flows of 6,000 ML per day (Maunsell, 1992). Regulators are generally closed to exclude floodwaters from the forest at flows up to about 11,000 ML/day (channel capacity) during the irrigation season (August to May ). This is so that the maximum volume of water can be delivered downstream. It also prevents unseasonal flooding in summer and autumn. Some regulators that were not previously watertight admitted a low flow during the irrigation season creating deep, open water wetlands (Leitch, 1988). They were made watertight in the 1970s and 1980s. They were only opened to maintain flood levels in ibis rookeries while birds were breeding or to pass excessive flows into the forest when the maximum capacity of the river channel was exceeded due to the rejection of ordered irrigation water due to local rain (Leitch, 1988). Such events are known as ‘rain rejection’ flows. Measures are being taken to prevent unseasonal flooding due to rain rejection flows by diverting excess flows elsewhere. If flows exceed 11,000 ML/day, action is taken to prevent overtopping of the river bank and subsequent erosion. Excess water can be diverted along the Mulwala Canal in New South Wales or diverted into the forest by opening regulators (Ward et al., 1992). For flows larger than 18,000 ML per day, fully open regulators no longer control bank overtopping and water floods out into the forest unimpeded (Maunsell, 1992). Regulators provide flexibility for use of the existing environmental water allocation for the Barmah-Millewa Forests and any future allocations under the Living Murray Initiative. A reduction in the frequency of the floods required to induce waterbird breeding has occurred since regulation of the Murray River. Leslie (2001) suggests that this may not be significant if waterbirds were able to reproduce successfully every time they were induced to breed. The duration of flooding, which Leslie considers to be a crucial factor in reproductive success, could be prolonged by opening specific regulators and directing environmental flows to nesting colonies and foraging areas when river flows are not high enough to sustain general forest flooding. Similarly, regulators could be used to direct water to specific parts of the forest to meet watering requirements for vegetation associations. A change in the rules for the operation of regulators is unlikely but has the potential to lead to a change in ecological character. Any such proposal should be assessed in relation to the impact on related ecosystem services.

Describing the ecological character of Barmah Forest Ramsar Site 20 5.2 Capacity of the Millewa Choke and the Barmah Choke Services to which the component relates: • Flood control • Provides drought refuge for waterbirds The Murray River is restricted near Picnic Point by the Millewa Choke which has a capacity of 10,600 ML per day and further downstream by the Barmah Choke which has a capacity 8,600 ML per day. At flows between about 8,600 and 10,600 ML per day, water is diverted into the Edwards River and Gulpa Creek. Flows over about 11,000 ML per day start to flood out into Barmah Forest. A change in the capacity of the chokes could have a significant impact on the level of flood control downstream in the Murray River, depending on the amount of change in capacity. An increase in the capacity of the chokes would reduce the likelihood of small floods entering the forest and reduce the capacity of the forest to provide drought refuge for waterbirds.

5.3 Groundwater levels Service to which the component relates: • Supports the largest Red Gum forest in Australia (together with Millewa Forest in NSW) A 1984-1987 study by the Rural Water Commission (1988) indicated that the water tables in Barmah Forest were generally low (11-14 metres below the surface) except adjacent to the river where a perched water table was present along the Murray River. Groundwater levels more than ten metres below the surface are likely to be unavailable to Red Gums. Shallow water tables may mobilise salt and increase salinity. SKM (unpub.) state that if groundwater levels were to rise within five metres of the forest surface, management of groundwater would be required. Changes in groundwater levels are likely and continued monitoring is recommended (see Section 4.2).

5.4 Hydrogeology Services to which the component relates: • Flood control • Groundwater recharge The following description of the hydrogeology of Barmah Forest and the surrounding region is from SKM (unpub.). The Barmah Forest is underlain by the following hydrogeological units. 1. The Coonambidgal Formation which dominates the surface geology and consists of relative shallow deposits of clay, sand and sandy clay. The Coonambidgal Formation formed from the deposits of recent streams and postdates the underlying Shepparton Formation. 2. The Shepparton Formation which is between 80 and 120 metres thick. It consists of thin, irregular and discontinuous sand and gravel beds that vary from isolated ribbon-like bodies to semi-continuous sheets. The Upper Shepparton Formation is composed of low permeability clay and clayey silts with lenses of high permeability sands. The Lower Shepparton Formation sediments have sand layers of high permeability and may have good hydraulic connections with the underlying Calivil Formation. 3. Unconsolidated sediments around 120 metres below the surface from the Renmark Group (basal aquifer system in the Murray basin) and Calivil Formation (the Deep Lead aquifer system). 4. Palaeozoic age bedrock greater than 180 metres below the surface with transmissivity and yield an order of magnitude smaller than overlying unconsolidated aquifer systems. The hydrogeology of the forest and surrounding areas is unlikely to undergo change and monitoring of groundwater levels rather than the hydrogeology is recommended.

Describing the ecological character of Barmah Forest Ramsar Site 21 5.5 Wetland depth Services to which the component relates: • Supports all four of the freshwater wetland types in Victoria • Supports depleted wetland types Wetlands were classified according to their depth and period of inundation in 1993/94. These are specified for each of the wetland categories in Barmah Forest in Table 10. A change in category would result from a significant change in maximum depth of a wetland. This could possibly take place over time due to sedimentation. A digital elevation model was recently completed for Barmah Forest which provides a sub-metre representation of the floodplain surface which is accurate to within 15 centimetres. However, data from the model is not readily available to date. The digital elevation model could be used to determine if there has been any change in wetland depth class since the wetlands were mapped in 1993/94.

Table 10. Depth and duration for freshwater categories found in Barmah Forest. Sources: DCE and Office of the Environment (1992) and DSE Corporate Geospatial Data Library WETLAND_1994 layer*.

Wetland category Depth (m) Duration of inundation Freshwater meadow < 0.3 < 4 months/year Shallow freshwater marsh < 0.5 < 8 months/year Deep freshwater marsh < 2.0 Generally remain inundated throughout the Usually deeper than 1.0 year but may dry occasionally. Permanent Open <0.5* Retain water for longer than 12 months, Freshwater Usually deeper than 1.0 however they can have periods of drying.

Barmah Forest supports wetland in two permanent open freshwater subcategories: shallow permanent open freshwater and reed-dominated. The literature variously states that shallow permanent open freshwater wetlands may be <2, <3 or <5 metres deep. Andrew Corrick (pers. comm.) advises that 0.5 metres is the most appropriate figure to use.

5.6.1 Hydrology - flooding requirements for wetlands Services to which the component relates: • Supports all four of the freshwater wetland types in Victoria • Supports depleted wetland types • Part of a large natural floodplain system (together with Millewa Forest in NSW) Approximately 90% of Barmah Forest is classed as wetland. Therefore, to fill wetlands, floods must be of sufficient size to inundate most of the floodplain. A flood of 60,000 ML/day is required to flood the whole forest (Keith Ward pers. comm.). Relatively frequent floods over 60,000 ML/day lasting more than a month would prevent permanent encroachment onto the floodplain of vegetation that is not flood tolerant. Floods of this magnitude continue to occur regularly (Figure 2). A change in ecological character would occur if such large floods declined in frequency.

Describing the ecological character of Barmah Forest Ramsar Site 22

30 Number of Events Average Duration of Events (days) rage rage 25

20

15

duration of the event event of the duration 10

5 Number of events greater than 60,000 ML/day and ave and ML/day 60,000 than greater of events Number

0 1910 - 1919 1920 - 1929 1930 - 1939 1940 - 1949 1950-1959 1960 - 1969 1970 - 1979 1980 - 1989 1990 - 1999

Figure 2. The frequency and average duration of floods over 60,000 ML/day in each decade for which records are available. Data are from Tocumwal.

5.6.2 Hydrology - flooding requirements for vegetation associations Services to which the component relates: • Supports representative vegetation communities • Supports a large variety of communities • Supports the largest Red Gum forest in Australia (together with Millewa Forest in NSW) • Supports the most extensive area of Moira Grass plains in Victoria • Supports a high diversity of species • Supports threatened species Leitch (1988) and Maunsell (1992) provided information on the flooding requirements for the vegetation associations mapped by Chesterfield et al. (1984) (Table 11). To maintain the status of the vegetation communities as they were at the time of Ramsar site listing in 1982, the area occupied by each association, as mapped by Chesterfield et al. (1984), will need to continue to be flooded in line with the requirements for the dominant species outlined in Table 11. It is assumed that maintaining the flooding requirements of the vegetation communities would also assist in maintaining species diversity and threatened species. A digital elevation model covering Barmah Forest was recently completed and is being used to develop a hydraulic model for the forest. The hydraulic model will allow the accurate mapping of inundation in relation to river flows (actual or simulated). It is proposed that the distribution of ecological vegetation classes (EVCs), which are currently being mapped, will be used in conjunction with the hydraulic model. This would allow monitoring of the flooding regime of the vegetation communities. It will be possible to identify where flooding requirements for a particular community are not being met. However, further work is required to relate the new EVCs to Chesterfield’s vegetation associations and revise flooding requirements so they relate

Describing the ecological character of Barmah Forest Ramsar Site 23 to EVCs (or groups of EVCs). Further studies may also be required to refine the understanding of flood requirements for particular EVCs. The history of flooding for the Murray River at Tocumwal indicates that the flood regime has changed since regulation (Figure 3). Flooding of the forest has occurred at flows of about 11,000 ML/day since the installation of regulators on distributary creeks. Since 1982, flows of 11,000 ML/day have been exceeded 50% of the time. This is greater than for the time before regulation, the time from the completion of Hume Dam to its enlargement and the time from the enlargement of Hume Dam till the time of Ramsar listing. However, flows of 20,000 ML/day are now exceeded for a lower percentage of time (Figure 3). The number of flooding events has been increasing (Figure 4), but this is due to an increase in the number of smaller floods and these have a decreased duration (Figure 4). The area and distribution of individual vegetation communities can be expected to continue to respond to this shift in the flood regime, as such responses can take decades. It can be concluded that these changes in flood regime will continue to affect all the vegetation communities on the floodplain, since the changes are greatest for flows in the range from which forest flooding commences (11,000 ML/day) to the flow required to inundate the whole floodplain (60,000 ML/day) (Figure 2). An increase in both frequency and duration for floods in the range of about 15,000-60,000 ML/day is likely to be necessary to maintain ecological character as it was at the time of Ramsar listing in 1982. Any further decline in the frequency or duration such floods would be of concern.

Table 11. Flooding requirements of vegetation associations. Sources: Maunsell (1992), Ward et al. (1992)# and Roberts and Marston* (2000).

% of Vegetation association Frequency Duration Ideal cycle of Maximum forest (number. (months) wetting and period of years in drying between 10) flooding (months) 1.8 Giant Rush 7-10 2-30 May – January 21 5.2* Moira Grass 10 5-7 (at July-December. 23 0.5-2.0 Rapid flood metres recession required depth)# after mid-summer # 13.8 Red Gum and Moira Grass 7-10 1-18 August to 23-24 4.3 Red Gum and Moira Grass and December Common Spike-rush 21.7 Red Gum and Terete Culm-sedge 5-10 1-18 August to 31-42 and grasses December 10.8 Red Gum and Terete Culm-sedge 5.7 Red Gum and Common Spike-rush 19.4 Red Gum and Warrego Summer Grass 2.0 Red Gum and Wallaby grasses 9.6 Red Gum and Swamp Wallaby and 3-10 0.5-18 August to 42 Brown-back Wallaby Grass December 0.4 Black Box 0-3* 0-1 August to March 40-42 3.2 Yellow Box-Grey Box 1.9 Disturbed sites with introduced - - - 44 species

Describing the ecological character of Barmah Forest Ramsar Site 24 105

1908-1934

1934-1960

104

1961-1982 Flow (ML/day)

1983-2004 103

0 10 20 30 40 50 60 70 80 90 100 Time Exceeded (%)

Figure 3. Flow exceedance curves for the Murray River at Tocumwal for four time periods: 5. 1908-1934 (blue): from the commencement of records to the completion of Hume Dam; 6. 1935-1960 (red): from the completion of Hume Dam until its enlargement; 7. 1961-1982 (green): from the enlargement of Hume Dam to the listing of the Ramsar site; and 8. 1983-2004 (black): from the listing of the Ramsar site to 2004.

100 Number of Events Average Duration of Events (days) 90

80 June to December to June

70

60

50

40

30 and average duration of the event the of averageand duration

20

10

0 Number of events greater than 11,000 greaterbetween ML/day events than of Number 1910 - 1919 1920 - 1929 1930 - 1939 1940 - 1949 1950-1959 1960 - 1969 1970 - 1979 1980 - 1989 1990 - 1999

Figure 4. Frequency and duration of June to December flows >11,000 ML/day at Tocumwal.

Describing the ecological character of Barmah Forest Ramsar Site 25 5.6.3 Hydrology - flooding requirements for waterbird breeding and abundance Services to which the component relates: • Provides one of Victoria’s largest waterfowl breeding areas, particularly for Australian White Ibis and Straw-necked Ibis • Supports an abundance of waterbirds The flooding requirements for successful colonially nesting waterbird breeding in Barmah Forest are summarised in Table 12. A change in this component would be indicated by a decrease in the frequency of floods that meet these requirements from the frequency recorded in the period 1961-1982, leading up to Ramsar site listing. A comparison of the flow data for the Murray at Tocumwal (Figure 5) and the record of years in which colonially nesting waterbirds have bred (Table 7) indicates that a flood peak of about 20,000 ML/day (or 606 GL/month) or greater is required to induce breeding. There are some anomalies in the data. Breeding was recorded in December 1967 when flows had been relatively low for some time. It was not recorded in 1981 when a period of high flows occurred. For most colonial waterbirds were recorded breeding, floods of 20,000 ML/day did not continue for long periods, but were often closely followed by another peak (Figure 6). Successive flooding above 20,000 ML/day probably ensured that flooding durations were adequate for breeding. The first flood peak often occurred in early winter. These relationships should be investigated more fully so that environmental flows can be used to maximise the chance of waterbird breeding success and maintain the level of waterbird breeding that occurred in 1961-1982.

Table 12. The flooding requirements for successful breeding by colonially nesting waterbird species in Barmah Forest. Source: O’Connor (pers. comm.)*, Leslie (2001)#.

Aspect of Requirements flood regime Seasonality • A flood pulse is required in September or October (or rarely November) to induce breeding.# • High stable water levels should continue for two months after the flood pulse with a gradual recession.# Water depth • Breeding is induced provided nest sites are sufficiently inundated#. • Rapid recession of floodwaters should be avoided. A sudden change in water depth of 0.3 metres under nest sites or in foraging areas is likely to lead to abandonment of breeding#. Magnitude • Floods must inundate both nesting and foraging areas#. • Much higher flows are required for successful breeding of egrets than for ibis. • A flood of at least 20,000 ML/day is considered necessary to induce breeding of colonially nesting waterbirds*. • However, in Barmah, ibis have bred successfully at specific locations (Boals Deadwoods) without widespread flooding. This was achieved by water being directed to the nesting area via a regulator at river flows of less than 11,000 ML/day.* Duration of • Flooding is required for up to 3.5 months after egg laying. A period before this is flooding also required for birds to prepare behaviourally, hormonally and nutritionally. Nest sites and foraging areas need to be inundated for at least 5 months#. Frequency • Frequency of flood events necessary to induce successful breeding events should reflect that which would occur under natural conditions#. The opportunity for successful breeding must occur within the lifespan of a species (20-25 years in some species with mean wild survival of 8-10 years)#.

Describing the ecological character of Barmah Forest Ramsar Site 26 2.5E+06

2.0E+06

1.5E+06

Flow (ML/month) 1.0E+06

5.0E+05

0 Jan-61 Jan-63 Jan-65 Jan-67 Jan-69 Jan-71 Jan-73 Jan-75 Jan-77 Jan-79 Jan-81

Figure 5. Flows at Tocumwal for the period 1961-1982. Flows are expressed in ML/month. The dotted line marks the average flow of 20,000 ML/day for one month (606,000 ML/month).

Flows greater than 20,000ML/day for 1961-1982

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

1982 Jan Feb M ar A pr May Jun Jul A ug Sep Oct N ov D ec

Figure 6. Duration of flows > 20,000 ML/day at Tocumwal for the period 1961-1982.

Describing the ecological character of Barmah Forest Ramsar Site 27 5.6.4 Hydrology - flooding requirements to provide drought refuge for waterbirds Services to which the component relates: • Provides drought refuge for waterbirds The availability of waterbird habitat is important throughout the year to provide drought refuge. Figure 7 shows that the number of flooding events have increased at Barmah Forest over the period of record. However the average duration of events has declined. Flooding between June and December is more likely to lead to breeding. Several flooding events between June and December occurred in the period leading up to listing of the Ramsar site (Figure 4). Data indicate that there is little likelihood of decline in the frequency of floods from the frequency in the period 1961-1982. However, a continuation of the apparent long term trend in declining flood duration would be of concern.

90 Number of Events rage Average Duration of Events (days) 80

70

60

50

40

duration of the event 30

20

10

Number of events greater than 11,000 ML/day and ave 0 1910 - 1919 1920 - 1929 1930 - 1939 1940 - 1949 1950-1959 1960 - 1969 1970 - 1979 1980 - 1989 1990 - 1999

Figure 7. Frequency and duration of flows >11,000 ML/day at Tocumwal.

5.6.5 Hydrology – to support a large natural floodplain Service to which the component relates: • Part of a large natural floodplain system (together with Millewa Forest in NSW) To fill wetlands, floods must be of sufficient size to inundate most of the floodplain. A flood of 60,000 ML/day is required to flood the whole forest (Keith Ward pers. comm.). Floods of this magnitude continue to occur regularly (Figure 2). There has been very little change in the time that flows have exceeded 60,000 ML/day since regulation (Figure 2). A change in ecological character would occur if such large floods declined in frequency or duration.

Describing the ecological character of Barmah Forest Ramsar Site 28 5.7 Habitat for breeding waterbirds Services to which the component relates: • Provides one of Victoria’s largest waterfowl breeding areas, particularly for Australian White Ibis and Straw-necked Ibis Nesting habitat requirements for colonially nesting waterbirds are summarised in Table 13. A change in this component would be signalled by a loss or significant decrease the availability of suitable nesting sites. Availability of foraging habitat is also important for successful breeding. This varies for species but, in general terms, is dependent on large areas of wetland habitat being flooded or availability of food in other nearby areas, for example in irrigation areas. Foraging habitat has not been specified further but its availability outside the Barmah-Millewa Forest should be investigated if a decline in waterbird breeding success occurs when nesting and foraging conditions in Barmah appear to be suitable. Table 13 . Nesting habitat requirements for colonially nesting waterbird species in Barmah Forest. Source: Loyn et al. (2002)*, Leitch (1988)**, Leslie (2001)# and Chesterfield et al. (1984)##.

Species or species Requirements group Ibis • Beds of Giant Rush or reeds* • Can also nest in trees# • Develop an attachment to traditional nest sites but also have the flexibility to colonise new nest sites if traditional sites become unsuitable#. Nesting locations in Barmah Forest for the period 1961-1982 are documented in Appendix 2. Royal Spoonbill • Emergent macrophytes# Egrets • Living Red Gum#. • Red Gums surrounding open swamps ** • Develop an attachment to traditional nest sites. They may not to colonise new nest sites if traditional sites become unsuitable#. Nesting locations in Barmah Forest for the period 1961-1982 are documented in Appendix 2. Little Pied Cormorant • Living Red Gum# Little Black Cormorant Pied Cormorant • Dead or Living Red Gum# Great Cormorant Yellow-billed Spoonbill • Tall Red Gums beside creeks##. White-necked Heron • Living Red Gum#. Whiskered Tern • On floating macrophytes#.

6. Conclusions In preparing the ecological character description for Barmah Forest Ramsar Site, most of the ecosystem services that were selected were able to be specified quantitatively. However, some could only be quantified in general terms. For example, species lists were available for species diversity and threatened species but data on the abundance and frequency of occurrence of individual species was not available. Data were not available to describe groundwater recharge or the service of supporting an abundance of waterbirds. Comprehensive waterbird breeding records were available for colonially nesting species, but not for other species. It is recommended that programs for monitoring species diversity and abundance are established with particular attention to monitoring waterbird abundance and breeding. Monitoring of groundwater levels is recommended rather that monitoring groundwater recharge. There is also a need to relate the vegetation associations described by Chesterfield et al. (1984) to EVCs, once these are completed. This will be necessary to monitor for changes in vegetation since 1982.

Describing the ecological character of Barmah Forest Ramsar Site 29 Hydrology was critical in maintaining most of the ecosystem services. It was generally possible to identify the aspects of hydrology which are of most importance in maintaining each of the services. For maintaining vegetation associations as they were in 1982, it is not likely to be adequate to maintain the hydrological pattern in the period leading up to Ramsar listing as changes in vegetation may take decades. Meeting flooding requirements for the associations will probably require a return to a more natural regime and monitoring is recommended. Further investigation of the relationship between hydrology and waterbird breeding is also recommended. The operation of regulators has been important in determining the connectivity of surface waters and, therefore, the local hydrology of parts of the floodplain. Regulator operation had caused some adverse change in the period leading up to Ramsar site listing, particularly in relation to unseasonal flooding from rain rejection flows. The arrangements for rain rejection flows are being addressed. Regulators also provide a degree of flexibility in maintaining flooding requirements for vegetation and waterbird breeding using the existing environmental water allocation for Barmah and Millewa forests and any future allocations under the Living Murray Initiative. Topography was also important for maintaining many of the ecosystem services. For 1982, topography could not be described at the fine level of detail which is ecologically meaningful. The recent digital elevation model provides the best benchmark for the Ramsar site, even though local changes in topography may have taken place since 1982. The digital elevation model will also be of value in constructing a hydraulic model for the floodplain that can be related to vegetation distribution. This will facilitate future monitoring of hydrology in relation to vegetation flooding requirements. The hydraulic model will also be valuable for monitoring if flooding requirements for waterbird breeding are being met. Monitoring of components that are unlikely to undergo change, such as hydrogeology and soil type, is not considered a priority. The Barmah and Millewa Chokes are unlikely to change naturally in the short term. However, there was a previous attempt to increase their capacity and any such proposal in the future should be assessed for the impact in ecological character on the Ramsar site.

Describing the ecological character of Barmah Forest Ramsar Site 30 References Bacon, P.E., Stone, C., Binns, D.L., Leslie, D.J. and Edwards, D.W. 1993. Relationships between water availability and Eucalyptus camaldulensis growth in a riparian forest . J. Hydrology 150 : 541-561.

Bureau of Meteorology. n.d. Living With Drought. http://www.bom.gov.au/climate/drought/livedrought.shtml

Chesterfield, E. 1986. Changes in the vegetation of the river red gum forests at Barmah, Victoria. Australian Forestry , 49 : 4-15.

Chesterfield, E. A., Loyn, R. H. and Macfarlane, M. A. 1984. Flora and fauna of Barmah State Forest and their management . Forests Commission of Victoria. Victoria.

Corrick, A.H. and Norman, F.I. 1980. Wetlands of Victoria 1. Wetlands and waterbirds of the Snowy River and Gippsland Lakes Catchment. Proc. R. Soc. Vict. 91 : 1 – 15.

Crabb, P. 1997. Murray-Darling Basin Resources. Murray Darling Basin Commission. Canberra.

Department of Conservation and Environment and Office of the Environment. 1992. An Assessment of Victoria’s Wetlands. Department of Conservation and Environment, East Melbourne.

Department of Natural Resources and Environment. 1997. Victoria’s Biodiversity. Directions in Management . Department of Natural Resources and Environment. East Melbourne.

Department of Sustainability and Environment 1999. Barmah Forest Ramsar Information Sheet. Department of Sustainability and Environment. East Melbourne. http://www.dse.vic.gov.au/DSE/nrence.nsf/LinkView/97E95CB32619DC20CA2572A00011BEF13D435 3ED718B354CCA2572A00012817A

Department of Sustainability and Environment. 2003a. Barmah Forest Ramsar Site Strategic Management Plan . Department of Sustainability and Environment. East Melbourne. http://www.dse.vic.gov.au/DSE/nrence.nsf/LinkView/97E95CB32619DC20CA2572A00011BEF13D4353ED 718B354CCA2572A00012817A

Department of Sustainability and Environment. 2003b. Biodiversity Action Planning: Landscape Plans for the Goulburn Broken CMA – Shepparton Irrigation Region – North Zones. Department of Sustainability and Environment. East Melbourne.

Department of Sustainability and Environment. 2004a. Atlas of Victorian Wildlife . Department of Sustainability and Environment, Victoria.

Department of Sustainability and Environment. 2004b. Victorian Flora Information System . Department of Natural Resources and Environment, Victoria.

Dexter, B.D. 1978. Silviculture of the River Red Gum forests of the central Murray floodplain. Proc. Roy. Soc. Vic. 90 : 175-194.

Environment Australia. 2001. A Directory of Important Wetlands of Australia. Third Edition. Environment Australia, Canberra.

Leitch, C. 1988. Towards a Strategy for Managing the Flooding of Barmah Forest. Conservation Forests and Lands. Benalla.

Leslie, D. 2001. Effect of river management on colonially-nesting waterbirds in the Barmah-Millewa Forest, south-eastern Australia. Regul. Rivers: Res. Mgmt . 17 : 21-36.

Describing the ecological character of Barmah Forest Ramsar Site 31 Loyn, R.H., Lumsden, L.F., and Ward, K.A., 2002. Vertebrate fauna of Barmah Forest, a large forest of River Red Gum Eucalyptus camaldulensis on the floodplain of the Murray River. Victorian Naturalist 119: 114-132.

Maunsell Pty Ltd. 1992. Barmah-Millewa Forest Water Management Plan . Murray-Darling Basin Commission.

Rees, D. 2000. Land Systems of Victoria. January 2000 Edition 3. Centre for Land Protection Research. Technical Report No. 56. Department of Natural Resources and Environment. Victoria.

Parkes, D., Newell, G. and Cheal, D. 2003 Assessing the quality of native vegetation: The “habitat- hectares” approach . Ecological Management and Restoration, Volume 4 supplement, pp.S29-S38.

Roberts, J., Young, B., Marston, F. 2000. Water regime of wetland and floodplain plants in the Murray- Darling Basin: A source book of ecological knowledge. CSIRO Land and Water. Technical Report 30/00. October 2000. Canberra.

Rural Water Commission of Victoria. (RWC). 1988. The Hydrogeology of the Barmah Forest . Investigations Report No. 1988/32. Rural Water Commission. Victoria.

Sinclair Knight Mertz. (SKM). Unpub. Barmah Forest Groundwater Monitoring Review to May 2003. Draft State Forests of NSW and NSW National Parks and Wildlife Service. 2002 NSW Central Murray State Forests Ramsar Information Sheet. http://www.environment.gov.au/cgi-bin/wetlands/report.pl?smode=RAMSAR&ramsar_refcodelist=64

Thoms, M.C. and Walker, K.F. 1990. Sedimentation in Barmah Forest . Unpublished Report, River Murray Laboratory, University of Adelaide, Adelaide.

Ward. K 1991. Investigation of the Flood Requirements of the Moira Grass Plains in Barmah Forest, Victoria . Department of Conservation and Natural Resources. Shepparton.

Ward, K., Leitch, C., Loyd, L. and Atkins, B. 1992. Interim Water Management Strategy for Barmah Forest, Victoria. Department of Conservation and Environment. Shepparton.

Wetlands International. 2002. Waterbird Population Estimates - Third Edition. Wetlands International Global Series No. 12. Wageningen, The Netherlands.

Describing the ecological character of Barmah Forest Ramsar Site 32 Appendix 1. Threatened species of flora and fauna Source: DSE (2003a).

FLORA Common Name Scientific Name FFG Listed Status in Status in Victoria Australia Austral Trefoil Lotus australis k Bluish Raspwort Haloragis glauca f. glauca k Buloke Allocasuarina luehmannii L Buloke Mistletoe Amyema linophylla ssp. Orientale v Button Rush Lipocarpha microcephala v Common Joyweed Alternanthera nodiflora k Corkscrew Spear-grass Austrostipa setacea r Downs Nutgrass Cyperus bifax v Dwarf Bitter-cress Rorippa eustylis r Dwarf Brooklime Gratiola pumilo r K Fat Spectacles Menkea crassa L e Forde Poa Poa fordeana k Hypsela Hypsela tridens k Leafy Templetonia Templetonia stenophylla r Matted Water-starwort Callitriche sonderi k Mountain Swainson-pea Swainsona recta L e E Mueller Daisy Brachyscome muelleroides L e V Narrow-leaf Sida Sida trichopoda r River Swamp Wallaby-grass Amphibromus fluitans k V Silky Browntop Eulalia aurea r Slender Bitter-cress Cardamine tenuifolia k Slender Sunray Rhodanthe stricta L e Slender Tick-trefoil Desmodium varians k Small Scurf-pea Cullen parvum L e E Smooth Minuria Minuria integerrima r Summer Fringe-sedge Fimbristylis aestivalis k Twiggy Sida Sida intricata v Umbrella Wattle Acacia oswaldii v Violet Swainson-pea Swainsona adenophylla e Woolly Buttons Leiocarpa panaetioides r Yelka Cyperus victoriensis k Yellow-tongue Daisy Brachyscome chrysoglossa L v FAUNA Common name Scientific name FFG Listed Status in Status in Victoria Australia Mammals Brush-tailed Phascogale Phascogale tapoatafa L, A Vul Large-footed Myotis Myotis macropus LR Squirrel Glider Petaurus norfolcensis L, A End Birds Australasian Bittern Botaurus poiciloptilus L End Australasian Shoveler Anas rhynchotis Vul Azure Kingfisher Alcedo azurea LR Barking Owl Ninox connivens L, A End Black-chinned Honeyeater Melithreptus gularis LR Blue-billed Duck Oxyura australis L, A End Brolga Grus rubicunda L Vul Brown Quail Coturnix ypsilophora LR Brown Treecreeper Climacteris picumnus LR Diamond Dove Geopelia cuneata LR Diamond Firetail Stagonopleura guttata L Vul Glossy Ibis Plegadis falcinellus LR Great Egret Ardea alba L Vul Grey-crowned Babbler Pomatostomus temporalis L, A End Hardhead Aythya australis Vul Hooded Robin Melanodryas cucullata L LR Intermediate Egret Ardea intermedia L Cen

Describing the ecological character of Barmah Forest Ramsar Site 33 FAUNA continued Common name Scientific name FFG Listed Status in Status in Victoria Australia Latham’s Snipe Gallinago hardwickii LR Little Bittern Ixobrychus minutus L End Little Egret Egretta garzetta L End Masked Owl Tyto novaehollandiae L End Musk Duck Biziura lobata Vul Nankeen Night Heron Nycticorax caledonicus LR Painted Honeyeater Grantiella picta L Vul Pied Cormorant Phalacrocorax varius LR Royal Spoonbill Platalea regia Vul Spotted Harrier Circus assimilis LR Superb Parrot Polytelis swainsonii L, A End V Whiskered Tern Chlidonias hybridus LR White-bellied Sea-Eagle Haliaeetus leucogaster L, A Vul Reptiles Bandy Bandy Vermicella annulata L LR Carpet Python Morelia spilota metcalfei L End Eastern Bearded Dragon Pogona barbata DD Tree Goanna Varanus varius Vul Amphibians Barking Marsh Frog Limnodynastes fletcheri DD Bibron’s Toadlet Pseudophryne bibronii End Fish Bluenose (Trout) Cod Maccullochella macquariensis L, L#, A Cen E Crimson-spotted Rainbowfish Melanotaenia fluviatilis L, L# DD Flat-headed Galaxias* Galaxias rostratus L# DD Freshwater Catfish Tandanus tandanus L, L# End Golden Perch Macquaria ambigua L# Vul Macquarie Perch Macquaria australasica L, L# End CE Murray Cod Maccullochella peelii peelii L, L# End River Blackfish Gadopsis marmoratus DD Silver Perch Bidyanus bidyanus L, L# Cen Murray Spiny Cray** Euastacus armatus L DD FFG Listed L Listed under the Flora and Fauna Guarantee Act 1988 . L# Listed under the Flora and Fauna Guarantee Act 1988 as part of the Lowland Riverine Fish Community of the Southern Murray-Darling Basin. A An action statement has been prepared for the management of this species. Status in Victoria (flora) e Endangered in Victoria, ie. Rare and at risk of disappearing from the wild state if present land use and other causal factors continue. v Vulnerable in Victoria, ie. Rare, not presently endangered but likely to become so soon due to continued depletion, or which largely occur on sites likely to experience changes in land use which threaten the survival of the species. k species poorly known, suspected of being in one of the above categories. r Plants which are rare in Victoria but which are not considered otherwise threatened. This category indicates relatively few known stands.

Describing the ecological character of Barmah Forest Ramsar Site 34 Status in Victoria (fauna) Cen Critically Endangered: A that is facing an extremely high risk of extinction in the wild in the immediate future.

End Endangered: A taxon that is not Critically Endangered but is facing a very high risk of extinction in the wild in the immediate future. Vul Vulnerable: A taxon that is not Critically Endangered or Endangered but is facing a high risk of extinction in the wild in the medium-term future. LR Lower Risk – near threatened: A taxon that has been evaluated, does not satisfy the criteria for any of the threatened categories, but which is close to qualifying for Vulnerable. In practice, these species are most likely to move into a threatened category should current declines continue or catastrophes befall the species. DD Data Deficient – A taxon where there is inadequate information to make a direct or indirect assessment of its risk of extinction based on its distribution or population status. Listing of taxa in this category indicates that more information is required and acknowledges the possibility that future investigation will show that a threatened classification is appropriate. Status in Australia under the EPBC Act 1999.

Status in Australia under the EPBC Act 1999 CE A native species is eligible to be included in the critically endangered category at a particular time if, at that time, it is facing an extremely high risk of extinction in the wild in the immediate future, as determined in accordance with the prescribed criteria. E A native species is eligible to be included in the endangered category at a particular time if, at that time: (a) it is not critically endangered; and (b) it is facing a very high risk of extinction in the wild in the near future, as determined in accordance with the prescribed criteria. V A native species is eligible to be included in the vulnerable category at a particular time if, at that time: (a) it is not critically endangered or endangered; and (b) it is facing a high risk of extinction in the wild in the medium-term future, as determined in accordance with the prescribed criteria.

Describing the ecological character of Barmah Forest Ramsar Site 35 Appendix 2 . Breeding records for colonially nesting waterbirds 1961-1982 Sources: # Victorian Wildlife Atlas (DSE 2004a); and * Chesterfield et al. (1984).

Species/group Date/time Count Latitude Longitude Locality Source (E=estimate) (NR=not recorded) Egrets 1964 NR Black Swamp * Whiskered Tern Dec 1964 200 nests (E) 35°56’25” 144°59’33” # Great Cormorant Dec 1964 20 nests 35°56’25” 144°59’33” # Little Pied Cormorant Dec 1964 250 nests (E) 35°51’52” 145°03’38” Duck Hole # Plain Egrets Spring 1966 NR Bullock * Creek Little Egret Mar 1967 NR 35°54’40” 144°59’00” # Great Egret Mar 1967 NR 35°54’40” 144°59’00” # Intermediate Egret Mar 1967 NR 35°54’40” 144°59’00” # Little Black Cormorant Dec 1967 NR 35°54’43” 144°58’56” # Little Black Cormorant Dec 1967 100 nests (E) 35°54’56” 144°58’40” # Little Egret Dec 1967 NR 35°54’56” 144°58’40” # Great Egret Dec 1967 250 nests (E) 35°54’56” 144°58’40” # Little Pied Cormorant Dec 1967 100 nests (E) 35°54’56” 144°58’40” # Intermediate Egret Dec 1967 250 nests (E) 35°54’56” 144°58’40” # Nankeen Night Heron Dec 1967 15 nests (E) 35°54’56” 144°58’40” # Great Cormorant Dec 1967 20 nests (E) 35°56’25” 144°59’33” # Little Pied Cormorant Dec 1967 1000 nests (E) 35°54’30” 145°02’26” Tarma # Lagoon Great Cormorant Dec 1967 NR 35°54’30” 145°02’26” Tarma # Lagoon Great Cormorant Dec 1968 NR 35°54’30” 145°02’26” Tarma # Lagoon Little Pied Cormorant Dec 1968 1000 nests (E) 35°54’30” 145°02’26” Tarma # Lagoon Great Egret 6/12/1968 NR 35°54’40” 144°59’00” # Nankeen Night Heron 6/12/1968 NR 35°54’40” 144°59’00” # Whiskered Tern 6/12/1968 NR 35°54’40” 144°59’00” # Little Pied Cormorant Dec 1969 NR 35°54’14” 144°58’33” # Little Black Cormorant Dec 1969 100 nests (E) 35°54’43” 144°58’56” # Pied Cormorant Dec 1969 100 nests (E) 35°54’43” 144°58’56” # Great Egret Dec 1969 250 nests (E) 35°54’56” 144°58’40” # Intermediate Egret Dec 1969 250 nests (E) 35°54’56” 144°58’40” # Little Black Cormorant Dec 1969 100 nests (E) 35°54’56” 144°58’40” # Little Egret Dec 1969 15 nests (E) 35°54’56” 144°58’40” # Little Pied Cormorant Dec 1969 100 nests (E) 35°54’56” 144°58’40” # Nankeen Night Heron Dec 1969 250 nests (E) 35°54’56” 144°58’40” # Great Cormorant Dec 1969 20 nests (E) 35°56’25” 144°59’33” # Great Cormorant Dec 1969 NR 35°54’30” 145°02’26” Tarma # Lagoon Little Pied Cormorant Dec 1969 1000 nests (E) 35°54’30” 145°02’26” Tarma # Lagoon Pied Cormorant Dec 1969 100 nests (E) 35°51’52” 145°03’38” Duck Hole # Plain Little Pied Cormorant Dec 1969 200 nests (E) 35°51’52” 145°03’38” Duck Hole # Plain White-necked Heron 1970 NR Smith’s * Creek Yellow-billed Spoonbill 29/11/1970 10 nests (E) 35°54’09” 145°08’38” # Royal Spoonbill Dec 1970 NR 35°55’40” 145°04’37” # White-necked Heron Dec 1970 NR 35°55’40” 145°04’37” # Little Pied Cormorant Dec 1973 200 nests (E) 35°55’48” 144°58’47” # Straw-necked Ibis Dec 1973 25 nests (E) 35°52’04” 144°58’57” # Straw-necked Ibis Dec 1973 1000 nests (E) 35°51’47” 145°01’42” Boals # Deadwoods Australian White Ibis Dec 1973 1000 nests (E) 35°51’47” 145°01’42” Boals #

Describing the ecological character of Barmah Forest Ramsar Site 36 Deadwoods Species/group Date/time Count Latitude Longitude Locality Source (E=estimate) (NR=not recorded) White-necked Heron 12/01/1974 NR 35°50’55” 145°24’41” # Great Cormorant Dec 1974 NR 35°54’30” 145°02’26” Tarma # Lagoon Little Black Cormorant Dec 1974 NR 35°54’30” 145°02’26” Tarma # Lagoon Little Pied Cormorant 1974 2000-3000 pairs Tarma * Lagoon Australian White Ibis 1974 and >100,000 (mainly Boals * and Straw-necked Ibis* 1975 floods Straw-necked Ibis), Deadwoods (uncertain count) and Top Island Whiskered Tern 18/01/1979 NR 35°56’25” 144°59’33” # Australian White Ibis 1978-79 >150 adults Reedy * Australian White Ibis 1978-79 400 nesting adults Boals * Deadwoods Australian White Ibis 1978-79 200 nesting adults Top * Island/Ross’ Swamp Australian White Ibis 1978-79 350 adults, 100 Pig Hole * nests Little Pied Cormorant Oct 1978 100 Island * Lagoon Little Pied Cormorant Oct 1979 105 Island * Lagoon Little Black Cormorant Oct 1979 3 nests (uncertain Island * identification) Lagoon Yellow-billed Spoonbill Oct 1979 1 nest (uncertain Budgee Creek * identification) White-necked Heron Oct 1979 1 nest (uncertain Budgee Creek * identification) Australian White Ibis 1979-80 300 adults, 220 Reedy * nests Australian White Ibis 1979-80 600 nesting adults Boals * Deadwoods Australian White Ibis 1979-80 30 adults , 30 Lower Pig * nests Hole Straw-necked Ibis 1978-79 >1000 nesting Boals * adults Deadwoods Straw-necked Ibis 1979-80 1500 nesting Boals * adults Deadwoods Straw-necked Ibis 1979-80 130 nesting adults Top * Island/Pig Hole

Describing the ecological character of Barmah Forest Ramsar Site 37