Muehlenbeckia horrida subsp. abdita
Encyclopedia
Muehlenbeckia horrida subsp. abdita, commonly known as Remote Thorny Lignum, is a critically endangered shrub endemic to Western Australia
.
wetland, in the Western Mallee
subregion of the Mallee
region in the South West Botanical Province of Western Australia.
It grows in waterlogged silt and sand, on the beds of Lake Bryde and East Lake Bryde. It depends for its survival upon a regular cycle of freshwater flooding followed by drying of the lake bed.
. Salinity loads in the Lakes were measured at around 160 tonnes in 1985, but had increased to around 1200 tonnes in 2005. This increase is attributable to a rising water table caused by widespread clearing for agriculture
. Other threats include interruption of the flooding/drying regime because of altered hydrology
; and recreational activities such as water skiing
. It is estimated that there are about 2000 plants left. There was previously a third population, but these were all dead in 2002, and the population is thought to be unrecoverable.
It is listed as "critically endangered" under Australia's Environment Protection and Biodiversity Conservation Act 1999
, and as "Rare" under Western Australia's Wildlife Conservation Act 1950
. The whole lake bed ecosystem has been classified as a critically endangered threatened ecological community
under the name Bryde.
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...
.
Description
It is an upright, spreading, leafless shrub, that grows to a height of from 60 to 120 centimetres. It has bright, light yellow clusters of flowers.Distribution and habitat
M. h. subsp. abdita is known only from two populations within the Lake Bryde-East Lake BrydeLake Bryde-East Lake Bryde
Lake Bryde-East Lake Bryde is a DIWA-listed freshwater wetland system in Western Australia. It is located at , in the Shire of Kent, 34 kilometres south-west of Newdegate...
wetland, in the Western Mallee
Western Mallee
Western Mallee is an Interim Biogeographic Regionalisation for Australia subregion in southern Western Australia. It is a sparsely populated subregion with an area of about 47,000 square kilometres, roughly centred on the town of Newdegate...
subregion of the Mallee
Mallee (biogeographic region)
Mallee, also known as Roe Botanical District, is a biogeographic region in southern Western Australia. Located between the Esperance Plains, Avon Wheatbelt and Coolgardie regions, it has a low, gently undulating topography, a semi-arid mediterranean climate, and extensive Eucalyptus mallee...
region in the South West Botanical Province of Western Australia.
It grows in waterlogged silt and sand, on the beds of Lake Bryde and East Lake Bryde. It depends for its survival upon a regular cycle of freshwater flooding followed by drying of the lake bed.
Conservation
Populations of M. h. subsp. abdita have declined severely in the last thirty years, mainly because of increasing salinitySalinity in Australia
Soil salinity and dryland salinity are two problems degrading the environment of Australia. Salinity is a concern in most states, but especially in the south-west of Western Australia....
. Salinity loads in the Lakes were measured at around 160 tonnes in 1985, but had increased to around 1200 tonnes in 2005. This increase is attributable to a rising water table caused by widespread clearing for agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
. Other threats include interruption of the flooding/drying regime because of altered hydrology
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
; and recreational activities such as water skiing
Water skiing
thumb|right|A slalom skier making a turn on a slalom waterski.Waterskiing is a sport where an individual is pulled behind a boat or a cable ski installation on a body of water, skimming the surface.-History:...
. It is estimated that there are about 2000 plants left. There was previously a third population, but these were all dead in 2002, and the population is thought to be unrecoverable.
It is listed as "critically endangered" under Australia's 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...
, and as "Rare" under Western Australia's Wildlife Conservation Act 1950
Wildlife Conservation Act 1950
The Wildlife Conservation Act 1950 is an act of the Western Australian Parliament that provides the statute relating to conservation and legal protection of flora and fauna....
. The whole lake bed ecosystem has been classified as a critically endangered threatened ecological community
Threatened ecological community
Threatened ecological community is a term used in Australia for ecosystems that are in danger of being lost due to some threatening process. Federally, threatened ecological communities are identified and protected under the Environment Protection and Biodiversity Conservation Act 1999. Some states...
under the name Bryde.