Talk:Barmah National Park/Temp

Ecology

Pelicans at Barmah Forest wetland

The Barmah Forest is located on a floodplain adjacent to the Murray River, and the ecosystem of the forest area and wetlands is adapted to and dependant on seasonal flooding. Flooding of the Barmah Forest occurs when flows in the Murray River exceed the capacity of the Barmah Choke (> 10400 megalitres a day), the channels, swamps and other low lying areas begin to flood. Larger floods of over 40 000 megalitres a day are required to most of the forest, and it is only at flows of greater than 60 000 megalitres a day that the majority of the river red gum forest and most of the black box woodland communities is flooded.

Table: Modelled occurrence and extent of flood events in Barmah Forest (from Halle & Butcher 2011)

River Flow (megalitres per day)	Average frequency (% of floods)	Average duration of flooding (months)	Longest dry period (months)	Inundation extent
10 400	78	3.6	45	All low lying areas and channels, floodplain marshes
16 000	70	3	45	Moira grass plains
35 000	57	2.1	116	Sixty % of river red gum forest and 30 % of river red gum woodland
60 000	25	0.7	201	Almost all river red gum forest, most of river red gum woodland and some black box woodland

There are two main vegetation types within Barmah National Park :

• River red gum forests and woodlands, found on the large areas of floodplain, and covering the majority of Barmah National Park
• Floodplain marshes, occurring in low lying areas which are flooded more frequently, consisting of several different vegetation communities

Box woodland

Small areas of box woodland occur on the higher and infrequently flooded areas of the Barmah Forest.

Non-floodplain box woodland occurs on higher ridges that are never flooded, occupying approximately 3% of Barmah Forest. The dominant trees are yellow box (Eucalyptus melliodora) and grey box (Eucalyptus microcarpa), with an understory dominated by gold-dust wattle (Acacia acinacea) and wallaby grasses (Rytidosperma spp.).

Black box (Eucalyptus largiflorens) dominated woodland occupies less than 1% of Barmah Forest, occurring on the driest portions of the floodplain, in areas that are only occasionally flooded for short periods. The understory is dominated by saloop (Einadia hastata), prickly salwort (Salsola tragus) and wallaby grasses (Rytidosperma spp.). The black box woodland grades into the river red gum woodland with increasing soil moisture and flooding.

Aboral mammals commonly seen in box woodland include common ringtail possums and squirrel gliders. White-plumed honeyeaters are common in box woodland, as are some small insectivorous birds such as yellow thornbills and white-winged trillersand yellow-rumped thornbills. Hooded robins and Gilbert's whistlers are present but rarely seen. Boulenger's snake-eyed skinks and Carpet pythons can also be found in the drier box forest.

River red gum forests and woodlands

Long-billed Corellas, Barmah National Park

River red gum (Eucalyptus camaldulensis) dominated forest and woodland is characteristic of Barmah Forest, and occupies the great majority of the Barmah National Park area.

River red gum woodland

River red gum woodland occupies approximately 10% of the Barmah Forest, occurring on the drier, less frequently inundated areas of the floodplain, with an understory dominated by brown-back wallaby grass (Rytidosperma duttonianum), swamp wallaby-grass (Amphibromus spp.) and common spike-rush (Eleocharis acuta).

River red gum forest

River red gum dominated forest occupies the majority of the floodplain, in areas that are frequently flooded. The dominant understory species varies with increasing soil moisture, with swamp wallaby-grass (Amphibromus spp.) and Warrego summer-grass (Paspalidium jubiflorum) in less moist areas, grading to to poong'ort (Carex tereticaulis) and Moira grass (Pseudoraphis spinescens) dominated understory in areas with higher flood frequency and longer duration of flooding.

No exclusively terrestrial native small mammals occur in the red gum forest, yellow-footed antechinus are present, but uncommon. In the 1850s, rufous bettongs and bridled nailtail wallabies were recorded from red gum forests near Gunbower, and may also have been present in Barmah Forest, both these species are now extinct in Victoria. Koalas have been re-introduced to the forest, Common brushtail possums are easily found, and Eastern grey kangaroos are numerous, particularly in the more heavily grassed areas.

Australian magpies, magpie-larks and willie wagtails are widespread in the forest, and emus can be seen in grassy plains and swamps. The most common birds in the red gum forest are Sulphur-crested cockatoos, galahs, crimson rosellas, white-plumed honeyeaters, striated pardalotes and brown treecreepers. Other species are less common, including varied sittellas and brown-headed honeyeaters, which forage from the bark of upper branches; and small insectivorous birds such as brown thornbill and striated thornbill. Barmah Forest provides habitat for several woodland and forest bird species listed as threatened in Victoria, including the barking owl, superb parrot and the grey-crowned babbler. In the 19th century, bell miners and crested bellbirds were recorded at Barmah forest, but no longer occur in the region.

Yellow-bellied water-skinks are found in the red gum forest, the most commonly seen snakes are red-bellied black snakes, tiger snakes and common brown snakes.

Introduced terrestrial mammals found in Barmah Forest include the European rabbit, brown hare, feral cat, red fox, feral horse, feral pig, and Sambar deer.. Introduced bird species include: common blackbird (in blackberry on riverbank), European goldfinch, house sparrow (around cattle yards) and common starling.

Floodplain marshes

Pelicans, Barmah National Park

The low-lying treeless areas of the Barmah forest are occupied by floodplain marshes which are seasonally inundated, and permanent freshwater lakes. Treeless wetland types include moist grasslands, aquatic herblands, Moira grass (Pseudoraphis spinescens) plains, giant rush (Juncus ingens) beds, and common reed (Phragmites australis) beds.

Barmah National Park is one of the largest breeding grounds of water birds in Victoria. When the forest floods, the flooded marshes attract many species of birds dependant on higher river flows and deeper, extended flooding for successful breeding. Winter floods rarely induce extensive breeding in the forest, most breeding occurs in spring.

Small numbers of white-bellied sea-eagles are found in the forest, and Black swans and Australian pelicans occur on treeless flood-plains. The most common species of ducks breeding in the forest during a major flood are grey teal, Pacific black ducks and Australian wood ducks. Magpie geese were common in the 19th century, but disappeared from Victoria until being recently reintroduced. Brolgas are also historically recorded as common at Barmah, hundreds of brolgas displayed and nested on War Plain in the 1920s. whiskered terns, hoary-headed grebes and Baillon's crakes are also found in the floodplain marshes.

Eastern great egret and royal spoonbill, Barmah Forest

Several threatened species of waterbird occur in the floodplain marshes at Barmah, including Eastern great egrets, intermediate egrets, little egrets and for two threatened and poorly known waterbirds, the Australasian bittern and the Australian little bittern.

Yellow-billed spoonbills, Eastern great egrets, white-necked herons, Little pied cormorants and little black cormorants nest in tall river red gums above flood waters, darters also nest in the large river red gums near creeks.

When floodwaters recede, the open muddy shores can attract low numbers of small waders including Palaearctic migratory species such as Latham's snipe and common greenshank.

The most common species of frogs recorded from Barmah Forest are the eastern sign-bearing froglet, common eastern froglet, eastern banjo frog, barking frog, spotted marsh frog and Peron's tree frog. Sloane's froglet, Sudell's frog, and Bibron's toadlet are present but much less common. The endangered giant banjo frog has been recorded from farmland just south of Barmah Forest.

Shallow freshwater marsh (herb)

(e.g. Duck Hole Plain, Little Rushy Swamp)

Well vegetated, shallowly-flooded grassy wetlands have been found to contain the highest numbers of vocalising and breeding frogs, however ephemeral rain-filled depressions are also important habitat.

Moira grass (Pseudoraphis spinescens) higher flood frequency, floods occurring almost every year

Deep freshwater marsh (reed beds)

(e.g. Reedy Lake, Boals Deadwood)

highest flood frequency, floods occurring almost every year

Some small land birds found in rush beds (Juncus spp.) include White-browed scrubwrens, little grassbirds and superb fairy-wrens.

Straw-necked ibis and Australian white ibis and cormorants nest communally in beds of giant rush (Juncus ingens) and sometimes common reed (Phragmites australis), which are typically flattened by ibis to make nesting platforms. Beds of giant rush are habitat for Australasian bitterns, Australian little bitterns prefer beds of cumbungi or common reed.

Permanent open freshwater lakes

(e.g. Barmah Lake, Hut Lake)

Channels and creeks

Platypus and rakali are found in the river and creeks.

Large native fish such as golden perch and Murray cod were once abundant when commercial fishing operated in the Murray River and adjoining Barmah-Moira Lakes in the 19th century. Significant decreases in catches were recorded by the end of the 19th century, golden perch, Murray cod and silver perch are now threatened species, and other native species are now uncommon, including river blackfish, freshwater catfish and Macquarie perch.

Introduced fish species found in fresh water at Barmah include European carp and redfin.