Restoring Burrima

Riplines across scalds, 2005. Press image to enlarge.

Riplines across scalds, 2005. Press image to enlarge.

In 2005 a group of local Macquarie Valley landholders formed the Macquarie Marshes Environmental trust to buy a small (259 hectare) property right in the heart of the Macquarie Marshes. We called it “Burrima” which means Black Swan in the language of the Wailwan People, who were the traditional Aboriginal owners of the Macquarie Marshes.

Vegetation and Restoration

We like to call Burrima a “window on the marshes” as in a small area it gives a snapshot of each of the main vegetation associations to be found in the marshes.

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Chenopod Shrubland

Saltbush re-growth, 2008. Press image to enlarge.

Saltbush re-growth, 2008. Press image to enlarge.

At the road entry site is the chenopod shrubland on the rarely flooded “high ground”. There is significant scalding in this area. Scalding occurs when the covering vegetation is removed by rabbits, sheep and drought leaving the bare topsoil, which then blows away. Very little grows on the bare claypan that is left.

In 2005 we put rip lines across many of these scalds and planted saltbush (top right). In May 2009 we completed a “water ponding” project on Burrima. This is a successful way of rehabilitating scalded country by building a series of low circular or horseshoe-shaped banks, which are then scattered with saltbush and native grass seeds. When it rains the runoff water is briefly trapped in the ponds, and this helps to establish the plants (right).

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Coolibah Woodlands

Coolibah woodland understorey, 2005. Press image to enlarge.

Coolibah woodland, 2005. Press image to enlarge.

The next vegetation type is the coolibah woodlands. Coolibahs are native Australian eucalypts that require some flooding to germinate but are also very resilient to drought.

The understorey plants of these woodlands have been the most effected by prolonged cattle grazing. In 2005 this understorey mainly consisted of the introduced weed Noogoora Burr and the native plant Roly Poly, which tends to dominate overgrazed black soils.

Since cattle were removed from Burrima we have seen a wonderful variety of native understorey plants which are gradually reclaiming the woodlands. We are also attempting to reintroduce native grasses back into Burrima.

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River Red Gums

Coolibah woodland, 2008. Press image to enlarge.

Coolibah woodland, 2008. Press image to enlarge.

The more regularly flooded country supports this River Redgum forest. River redgums are the only Australian eucalypt that can survive prolonged flooding of the root zone (up to 18 months), and they can also withstand prolonged dry conditions.

The understorey consists of a variety of wetland adapted plants, most notably reeds. Two types of reeds are found in the marshes- Cumbungi or “Bullrushes”, and Common Reed or Phragmites (a type of grass). As you can see from the photographs, most of the reeds had been grazed right to the ground when we purchased Burrima in 2005. The reeds have responded dramatically to the removal of the cattle. Now they form dense thickets which help to conserve and filter water, and when they dry off and die in the winter they form a thick mulch, covering the soil. Reeds protect against erosion, trap and spread water acting like a sponge, and reduce evaporation. They are vital to a healthy functioning wetland. When the next flood event comes, the decomposing vegetation will be the basis of the food chain which brings an explosion of life to the wetlands.

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North Marsh Reed Bed

In the far corner of Burrima there is a slice of the edge of the vast North Marsh reed bed. This is the largest reed bed in southern Australia, being around 5,000 hectares of Phragmites reeds, with a few semi permanent lagoons inside it.

When we purchased Burrima in 2005 the dividing fenceline between Burrima and this reed bed was clearly visible, as the reeds had been grazed off very heavily by the cattle. The reeds have made a strong recovery and are now recolonising their former area.

Phragmites reed bed 2005. Press image to enlarge.

Phragmites reed bed 2005. Press image to enlarge.

Phragmites reed bed 2008. Press image to enlarge.

Phragmites reed bed 2008. Press image to enlarge.