Site 5 Box Swamp

Site is of uncertain environmental stability

Description
The area is a proclaimed Government Road (the site is bisected by the Wimmera Highway), at an altitude of 110 m and on an almost level alluvial plain north of the Avon River.

The area has high habitat value due to the Woodland being dominated by a range of sizes and age classes of Eucalyptus largiflorens (Black Box) and the proximity of the Avon River.

Vegetation Description and Composition
This area is Open Woodland dominated by Eucalyptus largiflorens (Black Box). The understorey is predominantly Muehlenbeckia florulenta (Tangled Lignum) and Eragrostis infecunda (Cane Grass) and members of the Cyperaceace (Sedge) and Juncaceae (Rush) Families. The EVC represented is Plains Grassy Wetland and the surrounding vegetation type is Plains Grassy Woodland.

The 1997 survey indicated that up to 50% of the species present were introduced, mostly from the Asteraceae and Poaceae (Grass) Families. This had increased to between 60% and 70% of the species present in the 1998 to 2001 surveys. The number of introduced species recorded in 2002 has dropped from between 10% to 20% due to the continued dry conditions. These decreases were mainly from the Asteraceae and Fabaceae Families.

Box Swamp is dominated by Black Box
trees and Tangled Lignum

The site still has only one salt indicator plant being Lolium spp. (Rye Grass). This does not necessarily represent saline conditions because there are no other salt tolerant species present and the species is a common agricultural weed.

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 but one tree have increased in health since monitoring commenced in 1997. The other tree however is covered in dead branches, epicormic growth and has low canopy density.

Groundwater and Salinity
Two bores are located near Box Swamp and the water table is deeper than 20 metres below natural surface. The hydrograph record indicates that the bores have a rising trend of around 25 cm per year. The site is not under threat in the near future due to the depth of the water table but does have wider salinity implications for areas downstream, particularly the lower Avon River floodplain area and its margins.
Groundwater salinity readings in the bores in 2002 were 14 900 and 3 600 EC.

Birds
Bird species present at the time of the vegetation and tree health surveys were :-
Galah, Magpie, Red-rumped Parrot, Starling, Superb Fairy-wren, Striated Pardalote, Welcome Swallow, Willie Wagtail, Eastern Rosella, Brown Tree Creeper, White Plumed Honeyeater, Noisy Miner, Kookaburra and Red Wattlebird.

Threats to the site continue to be:

weed invasion
spillage of gravel and blue metal from adjacent gravel dump
possible long term pooling of water
dumping of rubbish

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