Site 9 Lake Lalbert

Site is in a stable environmental condition

Description
Lake Lalbert (Wildlife Reserve-Parks Vic.) is a Deep Freshwater Marsh fed by flood-waters from the Avoca River via Lalbert Creek generally every two to three years. It is at an altitude of 90 m and is on a riverine plain of gentle relief. The plain is the result of millions of years of deposition of sediments from the hill country. The wetland is of high habitat value, due to the diverse range of habitats available and large size of the area.

Vegetation Description and Composition
This site contains a vegetation survey quadrant on the edge of the lakebed, which is Red Gum Wetland EVC, dominated by Eucalyptus camaldulensis (Red Gum) and Eragrostis infecunda (Cane Grass). The other quadrat is located on the Lalbert creek inlet and is represented by Riverine Grassy Chenopod Woodland, dominated by Eucalyptus largiflorens (Black Box), Muehlenbeckia florulenta (Tangled Lignum) and various chenopod species.

The vrot Eryngium plantagineum (Long Eryngium) is still present, although level of cover has decreased from previous years. Of concern is the spread of introduced species Cuscuta campestris (Golden Dodder). Continued dry conditions have seen a decrease in the number and cover abundance of introduced species at the site.

Black Box / Tangled Lignum woodland along Lalbert Creek

There are three salt indicator species present at the lake including Atriplex semibaccata (Berry saltbush), Enchylaena tomentosa (Ruby saltbush) and Lolium sp. (Rye grass). It is questionable whether the presence of these species is an indication of saline conditions for they commonly occur in arid environments. The only way to know for certain whether the lake contains high soil salt concentrations is to perform soil tests.

Young red gum trees surround the edge of Lake Lalbert

Tree Health
Eight trees are monitored for tree canopy health using a 20-point system assessing canopy size and density, number of dead branches and extent of epicormic growth. Leaf damage by insects is also assessed. All trees have experienced declining health since 1997, with one tree dying in 2002. Poor health results are due to low canopy densities, extensive epicormic growth and dead branches. Dry seasonal conditions is likely to be the main reason for the decline, for the area has not been inundated in several years.

Water quality
Lake Lalbert has been dry since 1998 therefore limited water quality data has been collected and comparative analysis is not possible at this stage. The one macroinvertebrate survey completed in spring 1997 revealed a very high biological diversity in the populations present, suggesting a high level of ecological health.

Groundwater and Salinity
Watertables in the vicinity of the lake are very deep at >25 m and highly saline (>24 000 EC in 2002). Although some isolated areas of salinisation do exist in the nearby area, these are believed to be the result of localised groundwater perching and do not reflect the regional groundwater process.

Birds
Bird species seen at the time of vegetation and tree health surveys include:-
Galah, Magpie, Red-rumped Parrot, Red-capped Robin, Superb Fairy-wren, Sulphur-crested Cockatoo, Welcome Swallow, White-plumed Honeyeater, Willie Wagtail, Yellow-plumed Honeyeater, Brown Tree creeper (nest with two chicks), Australian Raven and Eastern Rosella.

Threats to the site continue to be:

possible increase to flooding frequency even though it is dry at present
Localised salinity from perched water tables
weed invasion, particularly Cuscuta campestris Golden Dodder
vehicle tracks through the vegetation survey area.

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