Sensitive Vegetation in the Northern Territory

Sandsheet Heath What is sandsheet heath? Many plant and animal species have adapted Sandsheets have acidic infertile soils overlaying to, and are largely or entirely restricted to this an impermeable deposit of clay or laterite, and are habitat type, including the Howard River Toadlet flooded during the wet season. (Uperoleia daviesae). Heath is the term used to describe the community The Howard River Toadlet was discovered in of plants found on the sandsheet. 2000, and although little is known about the species it appears to be confined to these Sandsheet heath has a mix of species, typically seasonally flooded sandy-plains. The Toadlet is with a diverse understorey of herbs and sedges the only Territory frog that is listed as threatened. and an overstorey of small trees or shrubs such as Grevillea pteridifolia, Banksia dentata, Verticordia Bladderworts cunninghamii and Melaleuca nervosa. Bladderworts (genus Utricularia) are a These seasonally saturated wetlands are fascinating group of small carnivorous plants important habitat for almost all of the carnivorous which have specialist traps for capturing and Utricularia species (bladderwort herbs) found in digesting small insects. These plants are well the Darwin region. adapted to life in a low-nutrient environment. Sandsheet Heath is also frequently associated with The Top End is among the richest places in monsoon rainforests, other wetlands and riparian the world for Bladderworts and their diversity is vegetation. These are all restricted vegetation highest on the sand plain habitats in the Darwin types in the Territory and hotspots for biodiversity. rural area. At least 26 Bladderwort species occur here, especially along the Howard River Why is sandsheet heath significant? and Adelaide River flood plains. Seven of these Sandsheet heath is a rare vegetation type present are officially recognised under NT legislation as in the Darwin region, covering 56 km2. Although ‘Vulnerable’ or ‘Near Threatened’. not formally listed as threatened, seasonally- Other threatened Sandsheet Heath plant saturated sandsheets supporting a heathland species include orchids and the herb Typhonium or wet herbfield are highly restricted and are taylori. identified as an ecosystem at risk within the Darwin region.

Sandsheet Heath

For more information visit www.denr.nt.gov.au Sandsheet Heath Threats Northern Territory Planning Scheme Land clearing for mineral extraction and rural nt.gov.au/property/building-and-development/ or agricultural expansion is currently the most northern-territory-planning-scheme significant management issue affecting the Other Fact Sheets in this series conservation values of the sandsheet heath. Monsoon Rainforest Vegetation fragmentation and hydrological change Mangrove Forest in the catchment are also likely to be affecting Old-Growth Forest susceptible wetland and rainforest habitats. Riparian Vegetation As land use intensifies near Darwin, there is a Further Information high likelihood that increased nutrient flows from Department of Environment nearby areas will have a detrimental impact on and Natural Resources the plants and animals which are adapted to the low nutrient environment of the sandsheets. Rangelands Division Ph. 08 8999 3631 Recreational misuse of these sensitive nt.gov.au/environment/soil-land-vegetation/ environments is increasingly apparent as the native-vegetation population of Darwin continues to grow. This includes fire-bug activity in the region, leading to Flora and Fauna Division Ph: 08 8995 5000 increased frequencies of fires in some areas. denr.nt.gov.au/about/flora-and-fauna-division Exotic grasses are becoming more widespread and fuelling hotter and more destructive fires. Recreational use of vehicles in these sandy areas leaves deep ruts which affect the local hydrology. References and Further Reading Land Clearing Guidelines nt.gov.au/property/land-clearing/apply-to-clear- I. Cowie freehold-land B. Stuckey Calochilus caesius Utricularia holtzei Sites of Conservation Significance nt.gov.au/environment/environment-data-maps/ important-biodiversity-conservation-sites/ conservation-significance-list Threatened Species I. Cowie denr.nt.gov.au/about/flora-and-fauna-division Utricularia hamiltonii What can we do to conserve Reduce the frequency of fires. sandsheet heath? • Preventing the spread of exotic grasses, • Ideally for conservation, development especially mission grasses and gamba grass, should be excluded from areas where into new areas in the Darwin region. Have threatened and rare species are known to be an active weed management plan for your concentrated. property. • Investigate establishing conservation • Reducing exotic grasses in areas with high agreements on areas of private land conservation value such as the Howard containing sandsheet heath or developing sandsheets, or where fires threaten other forms of reservation. properties. You can make a difference by: • Retaining native vegetation patches, buffers • Spreading the word about the importance and corridors within the horticultural and rural of sandsheet heath areas. They are lands around and to the east of Darwin. sensitive to disturbance and contain • Preventing recreational activities, such as threatened species. four wheel driving and quad bike riding, in • Preventing fire-bug activity in these areas. these sensitive areas.

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