Read the below fact sheet on Hymenachne to complete your table
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Hymenachne was introduced to Australia from South America to provide ponded pasture for cattle. Hymenachne has become an unwanted pest of stream banks, wetlands and irrigation ditches in coastal and central areas of Queensland. In some areas it has invaded low-lying sugarcane, fish habitats and natural wetlands with high conservation value.
Habitat and distribution Originally from South and Central America, hymenachne was released to the Queensland grazing industry in 1988 for use in ponded pasture. It is now found in various locations from Cape York to as far south as Casino in New South Wales and in the Top End of the Northern Territory. There is potential for hymenachne to colonise suitable habitats over much of coastal, northern Australia. Hymenachne will not persist in water with moderate to high concentrations of salt for part or all of the year. Control Measures
Mechanical or physical removal will not completely eradicate hymenachne because of the plant’s ability to reproduce vegetatively from very small pieces. The use of heavy earth moving machinery to remove hymenachne from drains has met with some success in North Queensland. Fire is a tool for the dry season. When integrated with other control methods, fire can improve overall results and reduce cost. In western shires, constant heavy grazing in dry conditions has removed hymenachne from the ponded pasture system. |
Impact to the Environment
Hymenachne has been used as a ponded pasture species for cattle production but has escaped cultivation, invading waterways including drains, lagoons, wetlands, creeks and rivers. Heavy infestations can affect waterbodies in a number of ways: Flooding Hymenachne can increase flooding by reducing the fl ow capacity of the drainage networks. Interference with irrigation and infrastructure Under flood conditions, plant material builds up at fences and bridges, collecting other floating debris. The combined weight may cause such structures to collapse. Water flow to irrigation equipment can be reduced due to the restrictive action of the roots, thus increasing pumping times and costs. Destruction of wildlife habitats Hymenachne infestations are a physical barrier for aquatic and semi-aquatic animals, restricting their territorial movements and breeding activities. Fishery biologists believe that carrying capacity and fish populations available for both commercial and recreational uses are being significantly reduced. Recreation and aesthetics The presence of thick areas of hymenachne degrades water quality for swimming and makes fishing impossible. The natural beauty of an open waterbody can be spoilt and further degraded as native aquatic plants, birds and animals are displaced (removed). Hymenachne also reduces access to waterways for recreation and wildlife. |