• Proposed
  • Under Assessment
  • ENPreliminary Assessed
  • 4Assessed
  • 5Published

Restiosporium dissimile Vánky & McKenzie

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Scientific name
Restiosporium dissimile
Author
Vánky & McKenzie
Common names
 
IUCN Specialist Group
Rust and Smut
Kingdom
Fungi
Phylum
Basidiomycota
Class
Ustilaginomycetes
Order
Ustilaginales
Family
Websdaneaceae
Assessment status
Preliminary Assessed
Preliminary Category
EN B2ab(ii,iii)
Proposed by
Cvetomir M. Denchev
Comments etc.
Anders Dahlberg, Cvetomir M. Denchev

Assessment Status Notes

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

Taxonomic notes


Why suggested for a Global Red List Assessment?

Restiosporium dissimile is a host specific smut fungus the sori of which replace and destroy the seeds of Apodasmia aff. similis (Restionaceae). The infection is systemic and all capsules of the infected plant are smutted (Vánky & McKenzie 2002; Vánky 2006, 2011). The host plant of this smut fungus was initially reported as A. similis (Vánky & McKenzie 2002) – a species which is endemic to New Zealand, being found in the Three Kings, North, South, Stewart, and Chatham Islands. Recently, it was demonstrated that the Chatham (Rekohu) Island plants of Apodasmia belong to a distinct species that differs from Apodasmia similis by a complex of morphological features and rbcL sequence divergence (Heenan et al. 2010). Because of this, the host plant of Restiosporium dissimile is considered as a Chatham Island endemic species awaiting formal taxonomic recognition (Heenan et al. 2010; de Lange et al. 2011). As a species with a very restricted distribution area, this plant in itself urgently needs to be assessed and ranked as a threatened species.

The smut fungus, Restiosporium dissimile, is known only from the type collection (Chatham Island, near Pakauwera, alt. 10 m) where it was collected in 1993 (Vánky & McKenzie 2002). Even if additional localities of R. dissimile are found on Chatham Island, it is unlikely that they will collectively comprise more than five locations and the species will fulfill the condition for EN of subcriterium a of B-criterion, i.e. a number of locations equal to or fewer than five. In this case, the area of occupancy is unlikely to exceed 500 km2. Even if the boundary of the whole island is taken into account, the extent of occurrence of R. dissimile will be about 1800 km2 and again will meet EN B1.

Apodasmia aff. similis is a coastal plant but is also found in wetlands. Continuing decline has been observed in the area, extent and quality of the habitat. In the location of Restiosporium dissimile, the host plant and its parasitic fungus are threatened by trampling and browsing by domestic stock and feral animals (cattle, horses, sheep, possums, pigs, etc.) (cfr. Dopson et al. 1999; de Lange 2003), competition from invasive plants (like marram grass, Ammophila arenaria) (Moore & Davis 2004), coastal erosion (cfr. de Lange 2003), fires (Walls & Baird 1995), and habitat disturbance from the use of motorised vehicles (Sawyer 2004). Trampling by people may also potentially be a threat since the location of the fungus is situated near the North Road. If a major fire or coastal erosion happen in that location, it can be detrimental.

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

This is a case of an endangered fungal species which is essentially an obligate parasite on an endemic plant species that has a very restricted distribution area and in itself also is a threatened species. Restiosporium dissimile fulfills B-criterion using AOO (area of occupancy) and meets EN B2, regarding subcriteria a (number of locations) and b (ii & iii) (continuing decline – observed, inferred or projected – in the area of occupancy, and in the area, extent, and quality of the habitat).


Geographic range

Restiosporium dissimile is known only from the type collection (Chatham Island, near Pakauwera, alt. 10 m) where it was collected in 1993 (Vánky & McKenzie 2002).

The host plant is endemic to Chatham Island and has a very restricted distribution area.


Population and Trends

There is no specific information on population size or trends. However, the host plant is a Chatham Island endemic species.

Population Trend: Deteriorating


Habitat and Ecology

The sori of Restiosporium dissimile develop in the seeds of Apodasmia aff. similis (Restionaceae). This fungus is host-specific and depends on its host plant.

Apodasmia aff. similis is a rush-like perennial herb, up to 2 m high (Heenan et al. 2010). It is a coastal plant but is also found in wetlands.

Marine Coastal/SupratidalCoastal Sand Dunes

Threats

Apodasmia aff. similis is a coastal plant but is also found in wetlands. Continuing decline has been observed in the area, extent and quality of the habitat.

In the location of Restiosporium dissimile, the host plant and its parasitic fungus are threatened by trampling and browsing by domestic stock and feral animals (cattle, horses, sheep, possums, pigs, etc.) (cfr. Dopson et al. 1999; de Lange 2003), competition from invasive plants (like marram grass, Ammophila arenaria) (Moore & Davis 2004), coastal erosion (cfr. de Lange 2003), fires (Walls & Baird 1995), and habitat disturbance from the use of motorised vehicles (Sawyer 2004). Trampling by people may also potentially be a threat since the location of the fungus is situated near the North Road. If a major fire or coastal erosion happen in that location, it can be detrimental.

Agriculture & aquacultureLivestock farming & ranchingHuman intrusions & disturbanceRecreational activitiesNatural system modificationsFire & fire suppressionInvasive & other problematic species, genes & diseasesInvasive non-native/alien species/diseasesNamed speciesClimate change & severe weatherStorms & flooding

Conservation Actions

The only known locality of this smut fungus is not included in a protected area.

The plant communities on the coastal dune slacks and wetlands need the following actions: control exotic weeds and prevent damage by humans (trampling and use of motorised vehicles) (Sawyer 2004).

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.

Land/water protectionSite/area protectionLand/water managementSite/area managementHabitat & 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

Use and Trade


Bibliography

de Lange, P.J. 2003. Sonchus grandifolius. In: New Zealand Plant Conservation Network. http://www.nzpcn.org.nz/flora_details.aspx?ID=62. Downloaded on 20 March 2015.

de Lange, P.J., Heenan, P.B. and Rolfe, J.R. 2011. Checklist of vascular plants recorded from Chatham Islands. Department of Conservation, Wellington.

Dopson, S.R., de Lange, P.J., Ogle, C.C., Rance, B.D., Courtney, S.P. and Molloy, J. 1999. The Conservation Requirements of New Zealand’s Nationally Threatened Vascular Plants. Threatened Species Occasional Publication, no. 13. Biodiversity Recovery Unit, Department of Conservation, Wellington.

Heenan, P.B., Mitchell, A.D., de Lange, P.J., Keeling, J. and Paterson, A.M. 2010. Late-Cenozoic origin and diversification of Chatham Islands endemic plant species revealed by analyses of DNA sequence data. New Zealand Journal of Botany 48: 83–136.

Moore, P. and Davis, A. 2004. Marram grass Ammophila arenaria removal and dune restoration to enhance nesting habitat of Chatham Island oystercatcher Haematopus chathamensis, Chatham Islands, New Zealand. Conservation Evidence 1: 8–9.

Sawyer, J.W.D. 2004. Plant Conservation Strategy, Wellington Conservancy (excluding Chatham Islands), 2004–2010. Department of Conservation, Wellington.

Vánky, K. 2006. The smut fungi (Ustilaginomycetes) of Restionaceae s. lat. Mycologia Balcanica 3: 19–46.

Vánky, K. 2011. Smut fungi of the world. APS Press, St. Paul, Minnesota, USA.

Vánky, K. and McKenzie, E.H.C. 2002. Smut fungi of New Zealand. Fungi of New Zealand. Vol. 2. Fungal Diversity Press, Hong Kong.

Walls, G. and Baird, A. 1995. Winds of Change: Monitoring Vegetation Condition and Trend in the Chatham Islands. Conservation Advisory Science Notes No. 130, Department of Conservation, Wellington, New Zealand.


Citation
Denchev, C.M., McKenzie, E.H.C. & Denchev, T.T. 2015. Restiosporium dissimile Vánky & McKenzie. In: The Global Fungal Red List Initiative. http://iucn.ekoo.se/iucn/species_view/381104/.


Known distribution - countries

Regional Population and Trends

Country Trend Redlisted