Saturday, December 1, 2012

Karri, Jarrah, and Mallee

Some of world's tallest trees, a wildflower paradise, and the rabbit-proof fence

I. Map boundaries: 30 to 40 degrees South; 110 to 120 degrees East

II. Country (Provinces--Regions): Australia (Western Australia—Goldfields-Esperance, Great Southern, MidWest, Peel, South West, and Wheat Belt economic development regions; local government areas surrounding Perth).

III. Overview
This map area includes all of the Great Southern, Peel, and South West economic development regions, most of the Wheat Belt region, and parts of the Esperance-Goldfields and Mid West regions. Perth and its surrounding local government areas are also included. All of the area is Mediterranean in climate, with winter rains heavy enough to support forests in the southwest. The rains gradually decrease to the inland and northeast, supporting woodlands and savannah. Along the southwest coast is the karri forest (ecoregion AA 1204), made up of tall evergreen eucalyptus trees. Inland is the jarrah forest (1210), also a tree-sized eucalyptus species, and further inland the vegetation grades to a savannah-like eucalyptus and melaleuca shrub area. The Southwest Australia savanna ecoregion (1209) is a wildflower viewing region. Showy flowers of the Proteaceae plant family are common. The region is characterized by winter rains, which create carpets of wildflower displays. The mallee vegetation (1202) is characterized by shrubs with a lignotuber, a storage root that is adapted to sprouting after a fire. To the northeast of the mallee and savannah areas is the eucalypt-mulga line, the boundary between eucalyptus-dominated vegetation and acacia-dominated desert vegetation. The Coolgardie woodlands (ecoregion 1201) of the northeastern Wheat Belt is this transitional desert area.

In the early 1900s, the Western Australia government made a concerted effort to allocate large sections of this area east of Perth for farming. The result was the vast ‘wheatbelt’ region that dominates the center of the map. However, these allocations were mostly made west of the rabbit-proof fence. In 1983, land allocations were discontinued, leaving a contrast visible on maps between the cultivated area and vast Mediterranean woodlands to the east (Watson et al. 2008). The rabbit-proof fence itself was conceived as a 2,000-mile coast-to-coast barrier to rabbits, which were overrunning Australia and moving west in the early 1900s. The fence did not serve as a barrier to rabbits, who were found west of the fence shortly after it was completed. Two other barriers were built, one further to the west and another to the north, but they failed to contain rabbits. The rabbit population was later stabilized by diseases. However, the fence did prevent kangaroos and emus from causing crop damage. The fence itself has become famous in studies of global climate change. Following the extensive clearing for agriculture, rainfall over the cultivated areas decreased. However, clouds continue to form to the east of the fence in a noticeable line. From a meteorological standpoint, this is thought to be due to the heterogeneous nature of the native woodland. Forests are taller than crops and tend to change wind speeds in ways that encourage cloud formation, it is hypothesized (http://honeybeesandhelium.com/2012/07/13/the-bunny-fence/).

To the west of the rabbit-proof fence is the Wheatbelt, created by the availability of water from the Goldfields Water Supply Scheme (Golden Pipeline). This historic civil engineering landmark and national heritage site transfers water from the Mundaring Weir eastward to the Wheatbelt. The original 560-km-long aboveground structure was completed in 1903 as the first major steel pipeline in the world. It extends from Mundaring Weir near Perth to Kalgoorlie to the east of the map area. Various sites along the pipeline contain museums and interpretive sites, and a bicycle trail follows the pipeline from Mundaring Weir to Northam through the jarrah forest area. Two other long-distance trails are of note in the map area. The Bibbulmun track is a long-distance walking path from Kalamunda to Albany, a distance of 963 km traversing the jarrah and karri forest regions. The Munda Biddi bicycle trail extends 1,000 km from Mundaring to Albany along a similar, but not the same, route as the Bibbulmun track. Munda Biddi is the longest off-road bicycle trail in the world.

IV. Terrestrial Ecoregions
For a detailed listing of sites in each ecoregion, keyed by number to the map, please see the webpage for Karri, Jarrah, and Mallee at https://sites.google.com/site/enviroramble/

A. Coolgardie woodlands (AA1201). This arid area in the northeast of the map area is transitional to desert and supports mallee scrub. Soils are low in nutrients and high in salinity. Low-lying heath shrubs of Eremophila are characteristic. This ecoregion is mostly east of the rabbit-proof fence and contains a predominance of native vegetation. It is considered a biodiversity hotspot. This ecoregion includes parts of the Wheatbelt and Esperance-Goldfields economic development regions
B. Esperance mallee (AA1202). East of Albany is a plain with granitic and quartz outcrops which supports shrubby vegetation of mallee and proteaceous scrub. The rabbit-proof fence runs northwest to southeast through this ecoregion, separating a more heavily cultivated area to the west from the great western woodlands to the east. This ecoregion is found in the Esperance-Goldfields, Great Southern, and Wheat Belt economic development regions.  Sites in this ecoregion include the Fitzgerald River Biosphere Reserve.
Fitzgerald River National Park (NP) is located in the Esperance-Goldfields and Great Southern economic development regions (2). This 329,000-acre area consists of a chain of isolated peaks called the Barren Range, an upland plain, a marine plain, and rugged coastal cliffs. The major habitat is mallee heath of Eucalyptus tetragonia and Banksia species. The park is an IBA for Carnaby’s black cockatoo, western bristlebird, malleefowl, western whipbird, and western ground parrot. The park has the largest number of animal species of any area in Western Australia, along with 1,800 plant species, 62 of which are endemic. The major visitor site is Point Ann.
C. Jarrah-Karri forest and shrublands (AA1204). This is the forest of wetter areas of southwestern Australia and is found on a narrow belt along the coast from Albany west to Margaret River. The wettest forest is of karri, or Eucalyptus diversicolor, which is an evergreen and the third tallest tree in the world, growing to 90 m. Karri trees live 350 years. Flowering karri trees attract purple-crowned lorikeets to feed on nectar. As rainfall and nutrients decrease inland, jarrah forests (Eucalyptus marginata) and marri forests (Eucalyptus calophylla) are found. The flora and fauna is highly endemic. There are endemic pitcher plants, frogs, worms, and crayfish. This ecoregion is found in the coastal areas of the Great Southern and South West economic development regions.  The Karri Forest Explorer Drive near Pemberton, South West region, highlights tall karri trees (up to 90 m) and passes by Beedelup NP,Big Brook Forest, Gloucester NP, and Warren NP. The westernmost karri forest is in Leeuwin-Naturaliste NP.
D. Swan Coastal Plain (AA1205). Found along the west coast from north of Perth to Cape Naturaliste, this area has diverse vegetation of Kwongan scrub, mallee, and heath. Tuart forests (Eucalyptus gomphocephala) grow south of Perth. Up to three fourths of the world’s carnivorous sundew species are found in this ecoregion. Some wildflowers are pollinated by possums. This ecoregion is found in the Mid West, Peel, South West, and Wheat Belt economic development regions and includes the local government areas around Perth.  There is a world heritage site and four Ramsar sites in this ecoregion.

Australian Convict Sites World Heritage site is in the Freemantle local government area (28). This area on the Swan River downstream from Perth memorializes the last of the original convict prisons to close. About 166,000 people were sent to Australia from 1787 to 1868. Of this, 10,000 were sent to the Swan River Colony in today’s Western Australia. These convicts worked on public infrastructure, agriculture, and mining. The prison consists of a complex of limestone buildings within a six-meter-high limestone perimeter wall. On site are 17 intact convict-built structures.
Becher Point Wetlands Ramsar site is in the Rockingham local government area (29). This system of wetlands and dunes supports sedgelands separated by sand ridges. Sedgelands are dominated by Baumea species.
Forestdale and Thomsons Lakes Ramsar site is in the Armandale and Kwinana Local Government Areas (28). These lakes are the best remaining examples of brackish seasonal lakes with fringing sedges in the Swan Coastal Plain and support 20,000 ducks and the Australasian bittern. Thomsons Lake is one of 19 lakes in Beeliar Regional Park.
Peel-Yalgorup System Ramsar site, found in the Peel and South West regions (30), supports shallow estuaries and lakes with 86 species of water birds, including thousands of shorebirds. The area is known for samphire vegetation of sedges fringed by low trees of Melaleuca. In the water are thrombolites, similar to stratomalites, formed by cyanobacteria and sediments. It includes Yalgorup NP, Peel Inlet, Harvey Estuary, Lake McLarty, Lake Mealup, and Erskine Conservation Park. Yalgorup NP extends from the Peel-Harvey estuary south to Harvey and includes a chain of ten lakes. Lake Clifton within the park is known for thrombolites, microorganism-derived structures similar to stromatolites. The NP is an IBA for the fairy tern, hooded plover, and Australian shelduck. Mammals include the chuditch, southern brown bandicoot, and western ringtail possum. The Peel-Harvey Estuary is an IBA for the fairy tern, blue-billed duck, and red-necked stint. Lake McLarty Nature Reserve is an IBA for red-necked stint, sharp-tailed sandpiper, and black-winged stilt.
The Vasse-Wonnerup System Ramsar site, South West region (31), is an extensive shallow wetland system supporting a breeding colony of black swan. It includes Tuart Forest NP and Vasse-Wonnerup Conservation Park.
E. Southwest Australia savanna (AA1209). Widely spaced eucalyptus savanna merges into acacia (wattle) as it moves inland toward sandplains. The northern portions of this ecoregion are famous for wildflowers including Banksia, kangaroo paws (Anigozanthos), Grevillea, and orchids. This is known as the Kwongan heaths. Nectar feeders such as possums and wallabies are part of the mammal fauna. Today much of the center of this ecoregion is a vast wheat-growing area, at least to the west of the rabbit-proof fence. However, the northern portions have extensive areas of native vegetation with heath and mallee vegetation. This ecoregion is found in the Mid West, Great Southern, and Wheat Belt economic development regions. There is one Ramsar site.

The Toolibin Lake Nature Reserve Ramsar site, Wheat Belt region (47), contains a large Casuarina obesa-dominated wetland supporting waterbirds such as freckled duck, cormorants, egrets, and night herons. This area is at the headwaters of the Arthur River. Mounds in the lake floor support trees. There are 25 species of breeding water birds.

F. Southwest Australia Woodlands (AA1210). Jarrah is dominant in the Darling range, but inland is wandoo (Eucalyptus capillosa and powderbark (E. accedens). Another eucalyptus is the marri tree. Marri trees attract silvereyes and honeyeaters to feed on the nectar. This ecoregion is found in the Great Southern, South West, and Wheatbelt economic development regions and includes local government areas on the east side of Perth. There is one Ramsar site.

The Muir-Byenup System Ramsar site, Great Southern and South West region (59), is an interconnected swamp with the largest natural sedge land in Western Australia and is an IBA, supporting 51,000 water birds, including Australian shelduck and Australasian bittern. It is also known for its orchid flora.
V. Freshwater Ecoregions of the World

Australia and Pacific Region
Temperate Coastal Rivers
801. Southwestern Australia. Stretching along the entire coastline in this map area but only extending a short distance inland, this ecoregion includes the perennial streams from the Arrowsmith River(north of the map area) to Fitzgerald River National Park at the eastern map boundary. Major rivers from north to south and west to east on the map are:

  • Hill River, draining the northern Swan coastal plain
  • Moore River, draining areas north ofPerth
  • Swan River, draining much of the Wheatbelt before entering the sea atPerth
  • Serpentine River
  • Murray River
  • Margaret River, the center of a wine region
  • Blackwood River, draining the Toolibin Lake Ramsar site
  • Warren River
  • Frankland River
  • Kalgan River
  • Pallinup River
  • Gairdner River
  • Phillips River (ephemeral)
There are 15 fishes in eight families, and there is an endemic family, the salamanderfish family, in the aquatic fauna. More permanent rivers lead to a diverse fish fauna of Galaxiidae, perches, and eel-tailed catfish (Plotosidae) familes. There are also endemic turtles and crayfishes.
Xeric Freshwaters and Closed Basins
804. Paleo. This area has isolated saline lakes but no permanent, fish-inhabited waterways and includes inland portions of the Mid West, Wheatbelt, and Esperance-Goldfields regions.
VI. Marine Ecoregions of the World

Temperate Australia Realm,Southwest Australian Shelf Province
209. Leeuwin. Found south of Perth and along the south coast of Australia. Sites exemplifying this ecoregion are:
Eclipse Island Nature Reserve, Great Southern Region (16). This island is an IBA for flesh-footed shearwater, great-winged petrel, and little penguin.
Ngari Capes Marine Park (77). Located offshore of Leeuwin-Naturaliste NP, this area includes part of Geographe Bay and Flinders Bay. Exposed headlands and boulder fields plunge to the sea, which has offshore kelp-covered reefs. Sea lions and whales may be viewed. The leafy seadragon, a protected species, is found in the area. The Hamelin Bay Wreck trail passes five shipwrecks.
Rottnest Island, Rottnest Island Authority, off of Perth(46). This 11-km-long island is most known for the globally threatened mammal, the quokka. It also contains six permanent salt lakes and is an IBA for fairy tern, banded stilt, and wedge-tailed shearwater. Offshore the island is a notable area for watching whales and dolphins and for snorkeling.
Shoalwater Islands Marine Park, Rockingham local government area (44). Penguin Island Conservation Park supports a breeding colony of little penguins. It is accessible by ferry and includes walking trails. Other limestone islands support seabird breeding. Offshore are dolphins and sea lions.
Swan Estuary Marine Park, Perth (28). Mudflats, seagrass beds, sedges, and saltmarsh support migratory wading birds, including the red-necked stint.
Walpole and Nornalup Inlets Marine Park, South West Region (24). The two inlets are encircled by Walpole-Nornalup NP and support 50 species of marine fish. The inlets can be viewed from the Bibbulmun Track and are known for canoeing.
Temperate Australia Realm, West Central Australian Shelf Province
211. Houtman. Found from Perth northward to Shark Bay. The following sites exemplify this ecoregion:
Carnac Island Nature Reserve, Fremantle (34). Between Garden and Rottnest Islands, this is a haulout area for sea lions.
Jurien Bay Marine Park, offshore of MidWest and Wheatbelt regions (78). The marine waters offshore fromWedge Island north to Green Head are part of this reserve on the Turquoise Coast. The reserve is offshore of the Namburg (23) and LeSeuer (16) National Parks. Offshore reefs create sheltered lagoons which contain extensive seagrass beds. The area is viewed as temperate and there are no coral reefs. There are about 15 groups of offshore islands within the reserve that provide breeding areas for sea lions and seabirds.
Marmion Marine Park, offshore of Wannaroo (79). Extending fromTrigg Island to Burns Beach, this park provides diving areas including offshore rocks, ledges, and caves. Seabirds on offshore rocks, marine mammals, and whales are present.
VII. References

Abell, Robin and 27 others. 2008. Freshwater Ecoregions of the World: A New Map of Biogeographic Units for Freshwater Biodiversity Conservation. Bioscience 58:403-414.
Australian Heritage Database. www.environment.gov.au/heritage (accessed July 2, 2011).
BirdLife International. 2012. IBA Factsheets. Downloaded from http://www.birdlife.org on 9 September 2012.
Birds Australia. http://www.birdata.com.au/iba.vm (accessed 7/2/11)
Gibbons, Bob. 2011. Wildflower Wonders: The 50 Best Wildflower Sites in the World. Princeton University Press and New Holland Publishers.
Olson, David M., et al., 2001. Terrestrial Ecoregions of the World: A New Map of Life on Earth. BioScience 51:933-938.
Spalding, Mark D. and 14 others. 2007. Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas. Bioscience 57:573-583.
Tourism Western Australia. www.westernaustralia.com (accessed 7/2/2011)
Watson, Alexander, Simon Judd, James Watson, Anya Lam, and David Mackenzie. 2008. The Extraordinary Nature of the Great Western Woodlands. The Wilderness Society of Western Australia..
Western Australia Department of Environment and Conservation. Park Finder. http://www.dec.wa.gov.au/ (accessed 7/2/11).
World Heritage List. http://whc.unesco.org/ (accessed 7/2/2011).

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