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  • Under Assessment
  • ENPreliminary Assessed
  • 4Assessed
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Ustilago neurachnes Vánky

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Scientific name
Ustilago neurachnes
Author
Vánky
Common names
 
IUCN Specialist Group
Rust and Smut
Kingdom
Fungi
Phylum
Basidiomycota
Class
Ustilaginomycetes
Order
Ustilaginales
Family
Ustilaginaceae
Assessment status
Preliminary Assessed
Preliminary Category
EN B2ab(ii,iii,v)
Proposed by
Cvetomir M. Denchev
Assessors
Cvetomir M. Denchev
Contributors
Teodor T. Denchev
Comments etc.
Anders Dahlberg

Assessment Status Notes

Preliminary red-list assessment: EN B2ab(ii,iii,v) (Endangered)

Taxonomic notes

The name is originally published as ‘Ustilago neurachnis’.


Why suggested for a Global Red List Assessment?

Ustilago neurachnes is a host specific smut fungus which destroys inflorescences of Neurachne tenuifolia (Poaceae).

The host plant, Neurachne tenuifolia, is endemic to Australia, with a very restricted distribution area in the Northern Territory. It occurs only in the MacDonnell Ranges (from Alice Springs to Mt Liebig), and in an isolated locality in Queensland (in Palmgrove National Park). At a state level, Neurachne tenuifolia is assessed as Near Threatened. It is noteworthy that the larvae of a threatened butterfly, Desert Sand-Skipper (Croitana aestiva), are entirely connected with this plant. It is a small butterfly that is endemic to Australia. Its distribution is restricted to the MacDonnell Ranges Bioregion, with EOO of ca. 1400 km2 (Palmer et al. 2012). The Desert Sand-Skipper is listed under the Australian Environment Protection and Biodiversity Conservation Act 1999, as Endangered, and under the Northern Territory Territory Parks and Wildlife Conservation Act 2000, as Endangered. The larvae of the Desert Sand-Skipper are monophagous on Neurachne tenuifolia. This plant is used by the butterfly for laying eggs and as food for the larvae. The distribution of the Desert Sand-Skipper is determined to a large extent by the distribution of the larval food plant (Palmer & Braby 2012).

The smut fungus, Ustilago neurachnes, is known only from the type collection (Northern Territory, western MacDonnell Ranges, Mt. Conway) where it was collected in 1989 (Vánky & Shivas 2008; Shivas 2010; Vánky 2011).

Neurachne tenuifolia (for this reason also the smut fungus on that plant) is threatened by three ongoing threats: invasive plant species, feral animals, and bush fires. The biggest threat to the survival of this grass species is caused by invasive plant species which outcompete the indigenous plants in the region. The Buffel Grass (Cenchrus ciliaris) is a very invasive species in Central Australia and in particular, in the area of the western MacDonnell Ranges (http://www.parksandwildlife.nt.gov.au/__data/assets/pdf_file/0011/3170/Draft_West_Macs_JMPlan.pdf). This grass forms dense monocultures and competes with, eventually displacing, native plant species, particularly grasses (Clarke et al. 2005), which have greatly declined following Cenchrus ciliaris invasion (http://www.cabi.org/isc/datasheet/14502). It was found that the habitats in the locations of Neurachne tenuifolia are degraded and is likely to continue to decline in quality due to the presence of the Buffel Grass. Other important invasive species, occurring there, are Couch Grass (Cynodon dactylon) and Mossman River Grass (Cenchrus echinatus).

Feral horses occur in large numbers in the Greater MacDonnell Ranges and are causing damage in some areas (http://www.lrm.nt.gov.au/__data/assets/pdf_file/0004/353461/Narwietooma-Station-Attachment-D-Macdonnell-Ranges.pdf).

Fire is another threat to Neurachne tenuifolia. It was found that this species is probably intolerant of fire (Prendergast & Hattersley 1985). It grows in a fire prone area (http://www.lrm.nt.gov.au/__data/assets/pdf_file/0015/10905/Desert_sand_skipper_NT_FINAL.pdf). Recently, bush fires in that region have increased dramatically due to increase in the development of invasive species, like Cenchrus ciliaris, leading to accumulation of biomass. The increased fire activity is seriously impacting on fire-sensitive plant species. In the extreme fire events of 2001–2002, approximately 50% of the West MacDonnell National Park was burnt (http://www.parksandwildlife.nt.gov.au/__data/assets/pdf_file/0011/3170/Draft_West_Macs_JMPlan.pdf).

Preliminary red-list assessment: EN B2ab(ii,iii,v) (Endangered)

This is an endangered parasitic fungus on a near threatened plant species that has a very restricted distribution area. Ustilago neurachnes fulfills B-criterion using AOO (area of occupancy estimated not to exceed 200 km2) and meets EN B2, regarding subcriteria a (number of locations) and b (ii, iii & v) (continuing decline – observed, inferred or projected – in the area of occupancy, area and quality of the habitat, and number of mature individuals).


Geographic range

The smut fungus, Ustilago neurachnes, is known only from the type collection (Australia, Northern Territory, western MacDonnell Ranges, Mt. Conway) where it was collected in 1989 (Vánky & Shivas 2008; Shivas 2010; Vánky 2011).


Population and Trends

There is no specific information on population size or trends. However, the host plant has very limited distribution within an area subjected to ongoing threats.

Population Trend: Deteriorating


Habitat and Ecology

Ustilago neurachnes is a smut fungus that destroys inflorescences of Neurachne tenuifolia (Poaceae). The fungus is host-specific and depends on its host plant.

Neurachne tenuifolia is a clumped perennial grass, with short rhizomes and erect or decumbent culm 30–50 cm long (Clayton et al. 2002). It is a xerophytic species which grows in hummock grasslands and Acacia shrublands. The only known locality of the smut fungus is situated on a slope of sandstone hill.

GrasslandSubtropical/Tropical Dry Lowland Grassland

Threats

Neurachne tenuifolia (for this reason also the smut fungus on that plant) is threatened by three ongoing threats: invasive plant species, feral animals, and bush fires. The biggest threat to the survival of this grass species is caused by invasive plant species which outcompete the indigenous plants in the region. The Buffel Grass (Cenchrus ciliaris) is a very invasive species in Central Australia and in particular, in the area of the western MacDonnell Ranges (http://www.parksandwildlife.nt.gov.au/__data/assets/pdf_file/0011/3170/Draft_West_Macs_JMPlan.pdf). This grass forms dense monocultures and competes with, eventually displacing, native plant species, particularly grasses (Clarke et al. 2005), which have greatly declined following Cenchrus ciliaris invasion (http://www.cabi.org/isc/datasheet/14502). It was found that the habitats in the locations of Neurachne tenuifolia are degraded and is likely to continue to decline in quality due to the presence of the Buffel Grass. Other important invasive species, occurring there, are Couch Grass (Cynodon dactylon) and Mossman River Grass (Cenchrus echinatus).

Feral horses occur in large numbers in the Greater MacDonnell Ranges and are causing damage in some areas (http://www.lrm.nt.gov.au/__data/assets/pdf_file/0004/353461/Narwietooma-Station-Attachment-D-Macdonnell-Ranges.pdf).

Fire is another threat to Neurachne tenuifolia. It was found that this species is probably intolerant of fire (Prendergast & Hattersley 1985). It grows in a fire prone area (http://www.lrm.nt.gov.au/__data/assets/pdf_file/0015/10905/Desert_sand_skipper_NT_FINAL.pdf). Recently, bush fires in that region have increased dramatically due to increase in the development of invasive species, like Cenchrus ciliaris, leading to accumulation of biomass. The increased fire activity is seriously impacting on fire-sensitive plant species. In the extreme fire events of 2001–2002, approximately 50% of the West MacDonnell National Park was burnt (http://www.parksandwildlife.nt.gov.au/__data/assets/pdf_file/0011/3170/Draft_West_Macs_JMPlan.pdf).

Agriculture & aquacultureLivestock farming & ranchingNatural system modificationsFire & fire suppressionIncrease in fire frequency/intensityInvasive & other problematic species, genes & diseasesInvasive non-native/alien species/diseasesNamed species

Conservation Actions

The only known locality of this smut fungus is not included in a protected area. Assessment and conservation of the host plant is needed. Ex situ conservation of the plant will not necessarily protect the fungus: in situ conservation is needed. Control the spread of the Buffel Grass.

Land/water protectionSite/area protectionLand/water managementSite/area managementInvasive/problematic species controlHabitat & natural process restorationEducation & awarenessAwareness & communications

Research needed

Further information is needed about population levels and distribution of the fungus.

ResearchPopulation size, distribution & trendsMonitoringPopulation trendsHabitat trends

Bibliography

Clarke, P.J., Latz, P.K. and Albrecht, D.E. 2005. Long term changes in semi-arid vegetation: invasion of an exotic perennial grass has larger effects than rainfall variability. Journal of Vegetation Science 16: 237–248.

Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. 2002 onwards. World Grass Species: Descriptions, Identification, and Information Retrieval. http://www.kew.org/data/grasses-db.html. Downloaded on 10 February 2015.

Palmer, C.M. and Braby, M.F. 2012. Rediscovery of the Desert Sand-skipper Croitana aestiva Edwards (Lepidoptera: Hesperiidae): morphology, life history and behavior. Australian Journal of Entomology 51: 47–59.

Palmer, C., Braby, M., Wilson, C., Pavey, C. and Ward, S. 2012. Desert Sand-Skipper (Croitana aestiva). In: Threatened Species of the Northern Territory. Northern Territory Government, Department of Land Resource Management.

Prendergast, H.D.V. and Hattersley 1985. Distribution and cytology of Australian Neurachne and its allies (Poaceae), a group containing C3, C4 and C3–C4 intermediate species. Australian Journal of Botany 33: 317–336.

Shivas, R. 2010. Neurachne smut (Ustilago neurachnis). Available online: PaDIL – http://www.padil.gov.au. Downloaded on 11 February 2015.

Vánky, K. 2011. Smut Fungi of the World. APS Press, St. Paul, Minnesota, USA.

Vánky, K. and Shivas, R.G. 2008. Fungi of Australia: the smut fungi. In: Fungi of Australia Series. Australian Biological Resources Study, Canberra & CSIRO Publishing, Melbourne.


Citation
Denchev, C.M., Shivas, R.G. & Denchev, T.T. 2015. Ustilago neurachnes Vánky. In: The Global Fungal Red List Initiative. http://iucn.ekoo.se/iucn/species_view/484801/.


Known distribution - countries

Regional Population and Trends

Country Trend Redlisted