• Proposed
  • Under Assessment
  • 3Preliminary Assessed
  • 4Assessed
  • 5Published

Hypocreopsis amplectens T.W. May & P.R. Johnst.

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Scientific name
Hypocreopsis amplectens
Author
T.W. May & P.R. Johnst.
Common names
 
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Kingdom
Fungi
Phylum
Ascomycota
Class
Sordariomycetes
Order
Hypocreales
Family
Hypocreaceae
Assessment status
Under Assessment
Proposed by
Tom May
Assessors
Peter Buchanan, Tom May
Contributors
Peter Buchanan, Anders Dahlberg, Tom May
Comments etc.
Jerry Cooper

Assessment Notes

Make a preliminary assessment. I suggest VU D1 (included potential unknown sites/individuals) less than 1000 mature ind, or C2a(i) EN if ongoing decline

Justification

A rare species, occurring in few sites, with low population numbers, including loss of at least one subpopulation over recent decades, coupled with decline in habitat and threat from increasing fire frequency and severity.


Taxonomic notes

Hypocreopsis amplectens is a distinctive macro-fungus, discovered in the 1990s and formally described in 2007 on the basis of material from Australia and New Zealand. Collections from the two countries are identical morphologically. ITS sequences of the one New Zealand collection and a collection from Australia are identical.

First observed in Australia in 1993, at Nyora, and informally known as Hypocreopsis sp. “Nyora” until its formal description.


Why suggested for a Global Red List Assessment?

A rare species, occurring in few sites, with low population numbers, including loss of at least one subpopulation over recent decades, coupled with decline in habitat and threat from increasing fire frequency and severity.


Geographic range

Found exclusively in Australia and New Zealand.

In Australia, known from Victoria and New South Wales.

In Victoria, Hypocreopsis amplectens has been observed at four sites: Wanderslore (Yarra Valley), Greens Bush (Mornington Peninsula) and two sites in West Gippsland: Adams Creek Nature Conservation Reserve (near Nyora) and Grantville. It has been a target species of the Fungimap fungi mapping scheme since 1999. In that time, only 19 records have been submitted to Fungimap (of which four are duplicate records of MEL herbarium specimens, and two are from outside of Victoria), making it one of the least recorded of the 100 target species (frequently recorded species have more than 1,000 records). There is a further record in the Victorian Biodiversity Atlas (also duplicated in Fungimap database). In total, there are 17 separate records of Hypocreopsis amplectens from Victoria from the four sites, over the period 1992 to 2018. There are voucher collections in the National Herbarium of Victoria (MEL) for all four Victorian localities.

In New South Wales, there is a single Fungimap record that is an observation from the New England area in northern New South Wales, accompanied by a photograph. From the photograph, this is certainly a member of the genus Hypocreopsis, and quite similar in appearance to Hypocreopsis amplectens, but there is no voucher collection. On balance, given that the species does occur also in New Zealand, this occurrence is accepted. Three years after the original record the observer re-visited the site and could not locate the species.

A sight observation was submitted to Fungimap from Cloister Lagoon (Tasmania) with no supporting image. This record is considered to be incorrect. The site was re-visited by Julie Fielder (c. 2014) using the precise coordinates from the original record, and Hypocreopsis was not found, but there were abundant lichens on wood that could be mistaken for Hypocreopsis due to clasping habit.

In New Zealand known from only two sites (1) Klondyke Corner, Arthurs Pass, Canterbury, where known from only one specimen collected there in 1983.  The Reserve is readily accessible from the highway. This and simlar forests in New Zealand have been intensively sampled for many years for Hypocreales, without locating further material. (2) Waterfall Track, Hanmer Springs (verified photo by Mike Pilkington). The North Canterbury population has been sought for several times in recent years and not re-found.


Population and Trends

Population - 234 individuals (144+60+30).

It is assumed that each substrate unit (i.e. piece of wood) supports a single genetic individual, even when there is more than one fruit-body present. Recording so far has not counted substrate units, only fruit-bodies. However, many of the fruit-bodies are single, and so counts of fruit-bodies more or less match counts of individuals.

Population in Victoria - 144 individuals. Intensive surveys at Wanderslore have located 21 fruit-bodies. At Nyora, at any one time, there have only been in the order of 10 fruit-bodies. At Grantville, at any one time there have only been in the order of 5 fruit-bodies. The total known individuals is therefore 36. It is noted that not all are necessarily mature, as some may be immature (not showing ostioles) or overmature (decayed and no longer releasing spores). Therefore the counts are maximums, and the number of mature individuals may be less. To allow for unreported fruit-bodies at known sites, figures are doubled (giving 72). To allow for other potential sites, this figure is doubled again, to 144. The population at Green Bush is considered extinct because several surveys in recent years have failed to locate fruit-bodies there.

For other sites, assume 10 individuals each, and also x2 for each of unreported fruit-bodies and unreported sites.

Population in New Zealand - from the two sightings - 60 individuals

Population in New South Wales - from the one sighting - 30 individuals.

Subpopulations are considered to be (1) New Zealand, (2) Australia, NSW, New England, (3) Wanderslore + Nyora + Grantville.

For the related Northern Hemisphere species (H. rhododendri) a specific polymerase chain reaction (PCR) assay has been developed (Grundy et al., 2012). Use of this assay on wood samples showed that H. rhododendri does not form mycelia within stems of the plant, but is considered to be growing in and on the fungal substrate (Hymenochaete). Therefore, counts of fruit-bodies are a reasonably accurate way of counting genetic individuals, and would only miss mycelial phases growing on the fungal host. If there is a mycelial phase on the host, it is not known if this phase would produce “crops” of fruit-bodies, or if there would be a single phase of fruit-body production. If there is a single phase, then any mycelia would not represent mature individuals. Due to the small diameter of the underlying wood, it is unlikely that there would be multiple flushes from a mycelium beyond the inferred generation time of 12 years.

Generation time is inferred as follows: For wood-decay fungi, Dahlberg & Mueller (2011) suggest a 20-50 year span for 3 generations. The span is based on the time taken for the substrate to decay. Given that Hypocreopsis amplectens occurs only on wood, and seems to be dependent on a wood-decay fungus (Hymenochaete) as host, the Dahlberg & Mueller estimate is used, taking the mid-point of the range (35 years, for 3 generations) and converting to one generation to give 12 years. Dahlberg & Mueller (2011) suggest adjusting the generation time according to the durability of the woody substrate. We do not have this information, but note that the diameter of substrate for Hypocreopsis amplectens is usually around 5 cm, and therefore will decay more quickly than larger substrates. Individual fruit-bodies of Hypocreopsis amplectens have been observed to persist for up to three years. With further research, the generation time could well be found to be less than 12 years.

The distribution is highly fragmented. Across the whole range, Hypocreopsis amplectens occurs in only very small areas, even within the current native vegetation, which is often itself highly fragmented, particularly in west Gippsland in Victoria, where two of the six sites where the species has been observed occur. In addition, where it does occur, Hypocreopsis amplectens is found within a relatively small area (one to several hectares only) within the larger area of the conservation reserves.

Information on locations and population numbers for Victoria has been provided by Sapphire McMullan-Fisher and Angela Little (Fungimap) who have been carrying out intensive surveys for the species at known and potential locations.

Population Trend:


Habitat and Ecology

Forms fruit-bodies on wood but is most likely a myco-parasite rather than a saprobe. Fruit-bodies are often overlying or near fruit-bodies of Hymenochaete, which is a resupinate fungus, and it is assumed at present that Hymenochaete is the host. The identity of the Hymenochaete is not known, and nor is it known if there is one or more species of Hymenochaete associated with Hypocreopsis amplectens. Reproduction is by spores. There are no known resting stages (such as sclerotia) and therefore establishment of new individuals is presumably from spores. Spores are not thick-walled or darkly pigmented, and so are assumed not to survive fire.

In Australia, occurs in heathy woodlands or forests on dead wood that is mostly standing or partially fallen (rather than lying close to the ground), in relatively long unburnt sites, not burnt for 30 years or more. Host plants include Leptospermum myrsinoides, L. continentale, Melaleuca squarrosa, Banksia marginata and Kunzea leptospermoides - with the Hypocreopsis frequently associated with a species of the fungus Hymenochaete, which is assumed to be the host of the Hypocreopsis. Several observations note that fruit-bodies are in ‘sheltered’ or ‘shady’ areas, but it is also recorded from more open areas.

In New Zealand, the single specimen collected (in 1983) was from a forest reserve on bark of native silver beech (Fuscospora cliffortioides).  Similar forests are widespread in upland areas of New Zealand.  A fungal host was not observed in the New Zealand specimen.


Threats

For the Australian populations, fire is a significant threat, especially repeated fires at short intervals. Due to the occurrence on standing, dead wood of relatively small diameter (about 5-10 cm), the entire substrate could be consumed by fire. It is not known how Hypocreopsis amplectens re-colonizes after fire, but it is assumed to be from unburnt populations as spores are not expected to survive fire. Because it is a myco-parasite, re-establishment after fire also required re-establishment of the presumed host (Hymenochaete sp.). There has been a recent (February 2019) wildfire at Grantville, that did not burn the area where Hypocreopsis occurs, but indicates the real threat of wildfires.

Land clearing is a significant threat. Immediately adjacent to the type locality in the Adams Creek Nature Conservation Reserve, sand mining, which completely removes the native vegetation is being actively carried out. Since the discovery of the species in the 1990s a new sand mine, occupying an area of about 50 hectares has been established.

Climate change is a potential threat, through increasing the intensity and frequency of fires, and also increased temperatures. Because Hypocreopsis ameplectens forms fruit-bodies on aerial substrates, of relatively low diameter, it is particularly exposed to higher temperatures.

For the New Zealand occurrence in North Canterbury, the forest reserve where the single known New Zealand specimen was collected is a secure alpine habitat, next to highway access, but unlikely to be affected by fire (relatively high rainfall) or land subsidence. However, the area is under significant threat from invasive pines.


Conservation Actions

The known sites are all in areas managed for nature conservation. The Adams Creek Nature Conservation Reserve was reserved in the first place partially on the basis of the occurrence of Hypocreopsis amplectens. There is a very active survey program for the species being carried out by Fungimap, including visiting known and potential sites, and photo-monitoring of known individuals.

However, there is no active management of Hypocreopsis amplectens in the reserved where it occurs, apart from avoiding controlled fire at the Adams Creek site.


Research needed

Establish ex-situ population
Carry out targeted surveys in suitable habitat
Monitor existing populations, especially response to fire
Identify the host fungus. For the New Zealand specimen, without obvious presence of a fungal host, DNA sequences from surrounding tissue may give an indication of host species. Identification of the host could potentially then be used to search for additional records of H. amplectans associated with specimens of the possible host.


Use and Trade


Bibliography

Dahlberg, A., and G. M. Mueller. 2011. Applying IUCN Red Listing Criteria for assessing and reporting on the conservation status of fungal species. Fungal Ecology 4:147-162.
Fungimap (2018) How to identify and record information to help save Tea-tree Fingers.

Grundy KC, Woodward S, Genney DR, Taylor AFS (2012). A molecular approach to explore the extent of the threatened fungus Hypocreopsis rhododendri within wood. Fungal Biology 116: 354-362.
Johnston, P.R., May, T.W., Park, D. & Horak, E. (2007). Hypocreopsis amplectens sp. nov., a rare fungus from New Zealand and Australia. New Zealand Journal of Botany 45: 715-719.
Little, A. (2018). Putting a Tea-tree finger on the pulse of fungi conservation. Fungimap Newsletter 59: 8- 10.
May, T.W. (1994). Conservation reserve for Hypocreopsis. Australian Mycological Newsletter 12: 2.
May, T.W. & Eichler, J. (1993). A Hypocreopsis (Fungi) from Nyora, Victoria. Victorian Naturalist 110: 76-77.


Known distribution - countries

Regional Population and Trends

Country Trend Redlisted