Victorian Riverina
Bioregion: Victorian Riverina

The Bioregional Landscape
The Natural Capital of the Landscape
Land Management Themes
Biodiversity Condition
Management Responses
Tables and Charts for the Victorian Riverina

The Bioregional Landscape
The Victorian Riverina bioregion covers approximately 24 000 square kilometres of the northern Victorian riverine plain, from Rutherglen in the east to Swan Hill and the Avoca River in the west. The southern and eastern boundary of the bioregion occurs at an elevation of about 150 metres. Rainfall ranges from 350 mm per annum in the west to an average of 600 mm per annum in the east.

The majority of the Victorian Riverina falls within the riverine plains land system which is characterised by flat to gently undulating land on recent unconsolidated sediments with evidence of former stream channels. Additional land systems include wide flood plain areas associated with major river systems including the Avoca, Loddon, Campaspe, Goulburn, Ovens and Murray rivers. Isolated areas of low hills also occur within the region, predominantly east of the Goulburn River and south of the Broken Creek.

At the time of European settlement, the Wembawemba, Barababaraba Jodajoda, and Way Wurru were the Aboriginal peoples living along the Murray River, from the area around Swan Hill in the west to present day Albury in the east, while areas of the plains further south from the Murray River were home to the Ngurai-illam wurrung and the Daung wurrung. Kow swamp was of great importance as a meeting site, as was Barmah Lakes. In the warmer months people congregated along the rivers, where fish weirs and traps provided an important food source; in the cooler parts of the year the population moved away from the major water bodies and dispersed in smaller groups through the plains area.

Grasslands and Grassy Woodlands once covered much of the Riverina but are now restricted to small but significant areas of public and private land. Major environmental features include the Barmah and Gunbower forests, the Kerang Lakes and Corop Lakes systems and the Murray River environment including the Gunbower Creek. These areas also comprise the major public land blocks within the region and provide a range of values for fauna, flora, recreation and tourism. Agriculture is the dominant land use with approximately 90 per cent of the land in private ownership. Major irrigation areas including the Shepparton Irrigation Region, the Rochester Irrigation District and the Torrumbarry Irrigation Region have been developed. Major townships in the area include Swan Hill, Kerang, Charlton, Echuca, Benalla, Wangaratta and Rutherglen, with Shepparton being the largest centre. Catchment Management Authorities include the North Central and Goulburn Broken, and to a lesser extent the North East. Fifteen local government areas occur either wholly or partly within the Victorian Riverina bioregion.

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The Natural Capital of the Landscape
Plains Grassy Woodland Complexes, Grassland Complexes, and Riverine Grassy Woodland Complexes are the three dominant BVTs in the bioregion. The Plains and Riverine Grassy Woodland Complexes are characterised by low density tree cover dominated by River Red Gum, Black Box, other box eucalypt species and/or Buloke and native Callitris pines. The shrubby layer, when present, included species such as Lightwood, Golden Wattle, Gold-dust Wattle and saltbushes. The Grassland BVT is dominated by Wallaby and Spear grasses with a mixture of herbs from the daisy, saltbush and pea families. Grassland Complexes and Grassy Woodland Complexes originally dominated much of the Riverina but are now largely fragmented. Since European settlement in the bioregion, these communities have been severely degraded and now only small remnant areas remain, with little protected on public land.

The bioregion supports numerous rare or threatened vertebrate species, and over 800 species of native vascular plants, of which over 70 are rare or threatened. Numbers of invertebrate fauna and non-vascular plants are not known.

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Land Management Themes
The open grassland plains and Grassy Woodlands in the Victorian Riverina Bioregion were settled and developed early. After the 1860s vast areas of land were cleared or modified to make way for cropping and pasture development. Later, around the turn of the century, large-scale irrigation schemes for the production of fodder crops, cereals and fruits were established on the Campaspe, Goulburn, Loddon and Murray rivers.

Problems of salinity and water logging were evident soon after irrigation began (as early as 1910) in the Kerang area. Vegetation clearance in the south has also had salinity impacts, contributing to rising water tables and saline discharge areas. Irrigation activities have resulted in increased salinity levels in the Murray River, due to the export of salt to the river. Much of this intensive agricultural land management has also resulted in increased nutrients in wetlands and rivers and tree decline through water logging, salinisation and insect attack. The greatest challenge facing natural resource managers in the Victorian Riverina is the development of land and water management regimes that can reduce, halt and then reverse the degradation of land occurring through changed hydrological regimes and salinisation. This degradation threatens both biodiversity and agricultural productivity in the bioregion.

Fertile soils coupled with a secure water supply made most of the area suitable for intensive agriculture. As a consequence, there is very little public land within the bioregion. Extensive strips of public land adjacent to rivers still exist — regular flooding meant that they were not suitable for intensive farming, though much of this area is grazed.

The larger River Red Gum forest blocks found in the Barmah, Gunbower and the Goulburn river areas have been intensively harvested since early settlement for timber products including sleepers, sawlogs and firewood. The composition and structure of the vegetation within these forest blocks has been substantially altered, resulting in a much younger, and in places, denser forest. These structural and age class changes have dramatically affected the diversity and abundance of faunal species, particularly those that are hollow-dependent. Changed flooding regimes and grazing in these areas has also modified the vegetation structure and composition.

All natural ecosystems in the Victorian Riverina have been depleted or highly modified, with only isolated vegetation patches remaining. Grasslands have been the most severely degraded with less than 1 per cent remaining, much of which is found on freehold land. Wetland systems within the bioregion have been altered due to changes in their hydrological cycle (restricted natural wetting and drying phases) and land management practices.

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Biodiversity Condition
Once the major habitat covering many thousands of square kilometres of the Victorian Riverina, native grassy woodlands and grasslands are now reduced to a tiny percentage of their original distribution. Northern Plains Grasslands have been listed as a threatened community under Schedule 2 of the Flora and Fauna Guarantee Act 1988. They are threatened by cultivation for cropping and irrigation, as well as inappropriate grazing regimes.

Inappropriate use of fire, weed invasion, and increased use of nutrients and chemicals also impact on the vegetation quality. Flora diversity and structure can be affected by poor management and these have important implications for rare or threatened fauna species. Many threatened plant species are now restricted to narrow road or rail reserves and their conservation will depend on the sympathetic management of these areas. A number of tools including Land for Wildlife and Public Authority Management Agreements are already in place to promote the protection of these areas on private and other public land, and some significant sites are protected under these arrangements.

Grassy Woodland Complexes, located on the more fertile soils, were targeted for development for agriculture. This broad-scale clearing has resulted in a landscape composed of isolated (often senescing) trees, with little or no native understorey and a sprinkling of small remnants. Many of these remnants are too small or isolated to support viable populations of fauna. Temperate woodlands such as these have been identified as being amongst the most endangered and poorly conserved vegetation types. Faunal species still found within this bioregion include ground dwelling and arboreal mammals including Yellow-footed Antechinus, Fat-tailed Dunnart and Lesser Long-eared Bat. Reptiles (Bearded Dragon, Olive Legless Lizard, Striped Skink, Eastern Brown Snake, and Woodland Blind Snake), Amphibians (Southern Bullfrog, Common Spade-foot Toad and the Spotted Marsh Frog) were all found within the area.

Remnant forests and woodlands are confined mainly to rivers and floodplains, with isolated pockets scattered throughout the region. Large River Red Gum forests including Barmah and Gunbower Forest are under threat from changed flooding regimes and a reduction in floodplain inundation. Intensive management of Red Gum forests for timber production has resulted in a reduction in the amount of mature remnant forest. Hollow-dependent species such as the Barking Owl, Carpet Python, Superb Parrot and Regent Parrot are in decline across the region. Loss of woody debris ground cover has affected fauna such as the Bush Stone-curlew, and the altered water regime has significantly reduced the number of colonially nesting water birds.

The lake systems, particularly the Ramsar listed wetlands, are important for waterbird conservation. The Kerang Lakes system (Ramsar listed) contains ibis colonies and the protection of colony breeding and roosting sites is very important for the conservation of a range of water birds, of which there are over 50 species recorded. The two major wetland systems within this bioregion, Kerang Lakes and Corop Wetlands, have been largely degraded by inappropriate management and altered water regimes resulting in an absence of flushing flows and increased salinity. The increased salinity has caused large-scale tree death in these wetlands and the diversity and abundance of fauna and flora species have been dramatically reduced. Shallow wetlands including freshwater meadows and shallow freshwater marshes have been significantly reduced both in number and size, which has particular significance for faunal species that require shallow wetland habitat for breeding or nesting, such as the Brolga. Most of the permanent deep wetlands remain, but riparian vegetation and water quality (especially in the Kerang Lakes area) have been much reduced.

The major impacts of European settlement included vast areas of land being cleared or modified to make way for pasture and cropping, and later, intensive irrigation resulting in species extinction, vegetation decline and fragmentation, erosion, salinity and a loss in biodiversity. Rising water tables associated with changed land practices and irrigation have resulted in alteration of the natural vegetation patterns and a dominance of salt tolerant species.

Pest plants and animals are widespread and have a serious impact upon the region. Introduced weeds, both agricultural and environmental, have reduced productivity and encroached upon the small, fragmented areas of remnant native vegetation. Pest animals including foxes, feral cats and starlings and carp prey upon or compete with native fauna for food and habitat. Rabbits and hares affect both agricultural productivity and reduce the recruitment and diversity of native flora.

Of the 99 known threatened species and undetermined number of threatened ecological communities in this bioregion there are:

• 67 listed vertebrates and plants, of which 18 have Action Statements;
• no listed invertebrates;
• one listed community, which does not have an Action Statement.

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Management Responses
The extensive depletion and fragmentation of many of the bioregion’s ecosystems means that the remaining areas are highly significant for biodiversity conservation. Regional Catchment Strategies have been prepared for the North Central and Goulburn Broken Catchment Management Authorities. These strategies have identified the importance of biodiversity to the Victorian Riverina region and a number of actions have been identified for implementation. Key strategic actions to protect and enhance the regional biodiversity have been identified in catchment salinity management plans, the draft conservation program for native grasslands and grassy woodlands, the draft Mid-Murray Forest Management Plan and catchment action plans produced by Trust for Nature. Many Shires within the region have roadside management plans and are beginning to address biodiversity protection in the revised Planning Schemes.

Given the large proportion of private land in the Victorian Riverina bioregion and the scattered small conservation reserves, biodiversity conservation will rely heavily on the owners and managers of private land and the network of road and rail reserves and other public land. Priorities for retention and rehabilitation should be directed towards those BVTs that are depleted (Riverine Grassy Woodland Complexes) and highly depleted (Plains Grassy Woodland Complexes, Grassland Complexes and Wimmera-Mallee Woodland Complexes). Land purchase to protect significant communities under-represented in the reserve system is at times a critical management option and has previously been applied within the Victorian Riverina. Use of the Land for Wildlife program to provide support and assistance to landholders will be a key process.

The bulk water entitlement process currently under way will identify the environmental requirements of rivers and associated wetlands, and attempt to provide these requirements. Preparation of an Environmental Allocation Annual Works Program to enable distribution of the environmental water allocation will ensure high priority wetlands along the Murray River obtain appropriate watering regimes. On-ground wetland works including construction of inlets and outlets will allow appropriate water regimes to be implemented. Management plans will be prepared and implemented for all significant conservation reserves, including Ramsar wetlands.

Together with the state-wide key directions outlined earlier, land and water managers and planners in the bioregion should consider the following priorities.

• Complete and implement the Mid-Murray Forest Management Plan and West Regional Forest Agreement, and management plans for all the major reserves.
• Finalise the bulk water entitlement process so that adequate and timely environmental flows are established for the rivers and wetlands.
• Reach Public Authority Management Agreements (PAMA) with public authorities that manage significant vegetation communities.
• Protect and fence remnants, encourage revegetation and property management planning which enhance off-reserve conservation of highly depleted vegetation types such as grasslands, Plains and Riverine Grassy Woodland Complexes, Box-Ironbark Forest Complexes, and Herb-Rich Woodland Complexes.
• Develop Roadside Conservation Plans for all shires particularly those in the west of the region to protect and enhance habitat for threatened species, such as the Grey-crowned Babbler.
• Develop a comprehensive conservation plan for the Northern Plains Grasslands.