Toolibin Lake
Encyclopedia
Toolibin Lake is a 493 ha nature reserve
containing a seasonal fresh
to brackish water
perched lake
or wooded swamp
, in south-western Australia
. It lies about 200 km south-east of Perth
, in the Shire of Narrogin
, and 40 km east of the town of Narrogin
, in the Wheatbelt region of Western Australia
. The lake is listed by the Australian Government
as a threatened ecological community
under the Environment Protection and Biodiversity Conservation Act 1999
.
at an altitude of 300 m asl
. It is about 300 ha in area and 2 km in diameter, has a maximum depth of 2 m, and is one of the last remaining inland freshwater lakes found in south-western Australia. It is one of a chain of wetlands occupying a palaeodrainage valley forming part of the northern Arthur River
system. Most of it is covered with a woodland
of water tolerant tree species, with a large open area on the eastern side. Many other Wheatbelt wetlands formerly supported a vegetation community and ecosystem similar to that of Toolibin, but clearing for agriculture has resulted in most such sites becoming saline with a concomitant loss of emergent vegetation. Toolibin is the only major lake in the catchment that has not become completely saline.
Toolibin Lake lies in a low rainfall area of the Wheatbelt with an average annual rainfall of 400 mm, mainly falling in May–August, with annual evaporation of 1800 mm. It usually only holds water at certain times of year; sometimes drying out completely for several years; sometimes holding water for extended periods.
, under which it was designated Ramsar Site 483 on 7 June 1990. The Ramsar site includes the entire area of the lake with some adjacent land on the northern, western and southern sides of the lake added in 2001 since the original site nomination, ensuring a buffer zone of at least 100 m width around most of the lake.
Toolibin is the only remaining example in Southwest Australia of a wetland with extensive living thickets of Swamp Sheoak
and the paperbark Melaleuca strobophylla
on the lake fringes and bed - one of the main wetland types in the region prior to agricultural development there. Flooded Gum
, Acorn Banksia
and Rock Sheoak
woodland occur on the higher ground and deep sands surrounding the lake. The vegetation includes submerged aquatic plants and sedges around the lake.
The vegetation community provides habitat, now rare in the central wheatbelt, for woodland birds and other animals. Toolibin and its environs support more breeding waterbird species — up to 25, including the rare Freckled Duck
, cormorants, egrets, night herons and spoonbills — than any other inland wetland in south-western Australia. It also supports a population of the threatened Red-tailed Phascogale
.
of the catchment for dry-land agriculture, particularly wool and cereal grain production; eutrophication caused by run-off containing agricultural fertilizers; invasive
weed
s changing the structure of the ecosystem and reducing natural vegetation available for food and shelter for animals; and grazing of regenerating seedlings by kangaroo
s, livestock
and rabbits
.
Actions to recover the environmental values of the lake and its catchment include the reduction of recharge – including revegetation and the protection of remnant vegetation; changes in farming methods, such as contour farming and the use of perennial grasses for grazing; the management of surface water in the catchment to reduce waterlogging of farmland, to decrease the salinity of water entering the lake, and to decrease salt loading of the lake; and groundwater pumping to lower the water table beneath the lake.
Nature reserve
A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...
containing a seasonal fresh
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
to brackish water
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
perched lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
or wooded swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
, in south-western Australia
Southwest Australia
Southwest Australia is a biodiversity hotspot that includes the Mediterranean forests, woodlands, and scrub ecoregions of Western Australia. The region has a wet-winter, dry-summer Mediterranean climate, one of five such regions in the world...
. It lies about 200 km south-east of Perth
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
, in the Shire of Narrogin
Shire of Narrogin
The Shire of Narrogin is a Local Government Area in the Wheatbelt region of Western Australia, about south-east of the state capital, Perth. Curiously, the town of Narrogin serves as the Shire's seat of government, despite the fact that it is not part of the shire itself...
, and 40 km east of the town of Narrogin
Narrogin, Western Australia
Narrogin is a large town in the Wheatbelt region of Western Australia, southeast of Perth on the Great Southern Highway between Pingelly and Wagin...
, in the Wheatbelt region of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. The lake is listed by the Australian Government
Government of Australia
The Commonwealth of Australia is a federal constitutional monarchy under a parliamentary democracy. The Commonwealth of Australia was formed in 1901 as a result of an agreement among six self-governing British colonies, which became the six states...
as a threatened ecological community
Community (ecology)
In ecology, a community is an assemblage of two or more populations of different species occupying the same geographical area. The term community has a variety of uses...
under the Environment Protection and Biodiversity Conservation Act 1999
Environment Protection and Biodiversity Conservation Act 1999
The Environment Protection and Biodiversity Conservation Act 1999 is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and culturally significant places...
.
Description
The lake lies in the catchment of the upper Blackwood RiverBlackwood River
The Blackwood River is a major river and catchment in the South West of Western Australia.The river begins at the junction of Arthur River and Balgarup River near Quelarup and travels in a south westerly direction through the town of Bridgetown then through Nannup until it discharges into the...
at an altitude of 300 m asl
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
. It is about 300 ha in area and 2 km in diameter, has a maximum depth of 2 m, and is one of the last remaining inland freshwater lakes found in south-western Australia. It is one of a chain of wetlands occupying a palaeodrainage valley forming part of the northern Arthur River
Arthur River, Western Australia
Arthur River is a small town located in the Wheatbelt region of Western Australia, between Williams and Kojonup on Albany Highway.-History:Arthur River is named after the river that flows through it, a headwater of the Blackwood River...
system. Most of it is covered with a woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
of water tolerant tree species, with a large open area on the eastern side. Many other Wheatbelt wetlands formerly supported a vegetation community and ecosystem similar to that of Toolibin, but clearing for agriculture has resulted in most such sites becoming saline with a concomitant loss of emergent vegetation. Toolibin is the only major lake in the catchment that has not become completely saline.
Toolibin Lake lies in a low rainfall area of the Wheatbelt with an average annual rainfall of 400 mm, mainly falling in May–August, with annual evaporation of 1800 mm. It usually only holds water at certain times of year; sometimes drying out completely for several years; sometimes holding water for extended periods.
Ramsar site
Toolibin Lake is recognised as a wetland of international importance under the Ramsar Convention on WetlandsRamsar Convention
The Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...
, under which it was designated Ramsar Site 483 on 7 June 1990. The Ramsar site includes the entire area of the lake with some adjacent land on the northern, western and southern sides of the lake added in 2001 since the original site nomination, ensuring a buffer zone of at least 100 m width around most of the lake.
Flora and fauna
Casuarina obesa
Casuarina obesa, commonly known as Swamp She-oak or Swamp Oak, is a species of Casuarina that is closely related to C. glauca and C...
and the paperbark Melaleuca strobophylla
Melaleuca strobophylla
Melaleuca strobophylla is a plant in the Paperbark family native to Western Australia.-Description:It is a spreading tree or shrub, growing to 3–12 m in height. The flowers are white, appearing from January to April. It is found on sandy silt soils in depressions, watercourses and the margins of...
on the lake fringes and bed - one of the main wetland types in the region prior to agricultural development there. Flooded Gum
Eucalyptus rudis
Eucalyptus rudis, Flooded gum, is a medium sized tree with rough, dark and light grey bark, however north of Perth its bark is smooth and very similar to Eucalyptus camaldulensis. Leaves are stalked, alternate, ovate to orbicular 12 x 7 cm, slightly discolourous and dull grey-green...
, Acorn Banksia
Banksia prionotes
Banksia prionotes, commonly known as Acorn Banksia or Orange Banksia, is a species of shrub or tree of the genus Banksia in the family Proteaceae. It is native to the southwest of Western Australia and can reach up to 10 m in height. It can be much smaller in more exposed areas or in the...
and Rock Sheoak
Allocasuarina huegeliana
Allocasuarina huegeliana, commonly known as rock sheoak or sighing sheoak, is a tree in the family Casuarinaceae. Endemic to Western Australia, it occurs throughout the Wheatbelt. It is now especially common on road verges, where it sometimes forms thickets.Rock sheoak grows to a height of...
woodland occur on the higher ground and deep sands surrounding the lake. The vegetation includes submerged aquatic plants and sedges around the lake.
The vegetation community provides habitat, now rare in the central wheatbelt, for woodland birds and other animals. Toolibin and its environs support more breeding waterbird species — up to 25, including the rare Freckled Duck
Freckled Duck
The Freckled Duck is a moderately large, broad-bodied duck native to southern Australia. The duck is protected by law...
, cormorants, egrets, night herons and spoonbills — than any other inland wetland in south-western Australia. It also supports a population of the threatened Red-tailed Phascogale
Red-tailed Phascogale
The Red-tailed Phascogale , also known as the Red-tailed Wambenger, is a small carnivorous marsupial found in central and western Australia...
.
Conservation
The main threats to Toolibin’s ecological community are salinisation and waterlogging due to clearingLand clearing in Australia
Land clearing in Australia describes the removal of native vegetation and deforestation and in Australia. Land clearing involves the removal of native vegetation and habitats, including the bulldozing of native bushlands, forests, savannah, woodlands and native grasslands and the draining of...
of the catchment for dry-land agriculture, particularly wool and cereal grain production; eutrophication caused by run-off containing agricultural fertilizers; invasive
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s changing the structure of the ecosystem and reducing natural vegetation available for food and shelter for animals; and grazing of regenerating seedlings by kangaroo
Kangaroo
A kangaroo is a marsupial from the family Macropodidae . In common use the term is used to describe the largest species from this family, especially those of the genus Macropus, Red Kangaroo, Antilopine Kangaroo, Eastern Grey Kangaroo and Western Grey Kangaroo. Kangaroos are endemic to the country...
s, livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
and rabbits
European Rabbit
The European Rabbit or Common Rabbit is a species of rabbit native to south west Europe and north west Africa . It has been widely introduced elsewhere often with devastating effects on local biodiversity...
.
Actions to recover the environmental values of the lake and its catchment include the reduction of recharge – including revegetation and the protection of remnant vegetation; changes in farming methods, such as contour farming and the use of perennial grasses for grazing; the management of surface water in the catchment to reduce waterlogging of farmland, to decrease the salinity of water entering the lake, and to decrease salt loading of the lake; and groundwater pumping to lower the water table beneath the lake.