Assessment Notes

Justification

Hygrocybe mucronella mainly occurs in calcareous semi-natural grasslands, and to a lesser degree (probably <30% of the population) in rich/calcareous forests (like rich broadleaved forests and calcareous pine forests), up to subalpine areas. The habitats are declining due to changing agricultural practices, development projects, mining, forestry and pollution. In grassland habitats we assume a habitat loss and population decline of 30-50% over the past 50 years, probably near 50%. In forests the habitat loss and population decline is estimated to be 15-20% over the same period. Over the distribution range we assume an average habitat loss and population decline of more than 30% over the last 50 years (approximately three generations: one generation is assumed to be about 17 years). Habitat quality of grasslands has also become impaired and the decline in population size over this time could be even higher, strengthening the assumption of 30-50% population decline. This decline in habitat is ongoing and expected to continue over the next 50 years. GBIF lists more than 1,700 occurrences from Europe, including duplicates, but due to lacking data in GBIF there could be roughly 2,000-3,000 known localities. The species is assumed to have a population of more than 20,000 mature individuals. At a global scale (i.e. Europe) the population decline is assumed to be on average 30-50% in 50 years (past, present and future). The species meets the threshold for Vulnerable under criteria A2ce+3ce+4ce.

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Taxonomic notes

GBIF (2021) shows some records from North America but this is a different species (Lodge et al. 2014). Unpublished data show that this is more than one species. Here they are treated as one, as all available information is connected to Hygrocybe mucronella sensu lato.

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Geographic range

Hygrocybe mucronella occurs in most parts of Europe, from the lowlands up to subalpine areas. Eastwards the distribution is uncertain because of lack of data; in Russia the species is reported from Irkutsk Oblast, Khabarovsk Krai, Krasnoyarsk Krai, Leningrad Oblast, Novgorod Oblast, Primorsky Krai, Pskov Oblast and Tula Oblast (T. Svetasjeva pers. comm.). As the prior report from North America is documented as different species (Lodge et al. 2014), reports from Russian Far East could also be a different species.

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Population and Trends

According to GBIF (2021) there are more than 1,700 occurrences from Europe, including duplicates, but due to paucity of distribution coverage in GBIF there could be roughly 2,000-3,000 known localities. Each site could contain about 10 mature individuals. Thus, the species is assumed to have a population of more than 20,000 mature individuals. Based on available information on trends in semi-natural grasslands, Griffith et al. (2013) estimated a habitat loss of 90% over the last 75 years for the CHEG-fungi (grassland fungi of Clavariaceae, Hygrocybe s.l., Entoloma and Geoglossaceae) as a whole in Western Europe. According to the Food and Agriculture Organization of the United Nations (FAO), the area of grasslands in the EU declined by 12.8% over 13 years (1990-2003) (FAO 2006). Also other sources point to a habitat loss in semi-natural grasslands of roughly 1% per year in Europe over a longer time, although the data quality is not always very good. The habitat quality of semi-natural grasslands is also declining, strengthening the population decline. In forests the habitat loss and population decline could be estimated to 15-20% over the same period.

Over the whole distribution range we assume a total habitat loss and population decline of at least 30-49% over the last 50 years. As the habitat quality is also declining, population decline could be higher. This trend is ongoing and expected to continue into the future (Janssen et al. 2016).

Population Trend: decreasing

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Habitat and Ecology

Hygrocybe mucronella grows in calcareous, mycologically rich but nutrient-poor semi-natural grasslands and to a lesser degree (probably <30% of the population) in rich/calcareous forests (such as rich broadleaved forests and calcareous pine forests). Northwards it extends into the northern boreal zone, in the Alps up to 2,130 m asl. In Norway, the habitat specificity has been quantified: N=224; 65% confirmed to semi-natural grasslands, and 24% in rich forests (Jordal et al. 2016), and similar patterns are found in other European countries. It is found from sea level up to subalpine areas in Scandinavia and in the Alps. The nutrient strategy is unknown, but all "CHEG-fungi" could have some kind of biotrophy or mycorrhiza (Halbwachs et al. 2018). The fruit bodies are short-lived (weeks), but the mycelium is suspected to be long-lived; > 50-100 years.

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Threats

Habitat destruction and abandonment are the main threats to semi-natural grasslands. The most important process is probably overgrowing due to ceased grazing/mowing of old semi-natural grasslands as part of intensification of agriculture. Further modern cultivation methods like use fertilizers, pesticides and ploughing also can have an impact. Also, changed land use with the construction of roads, industrial areas, settlements etc. impact some areas. The latter factors can influence localities in forests, where modern forestry can also be a threat. Declines is expected to continue, as areas of semi-natural grasslands are of little economic importance in modern agriculture. Most CHEG grasslands (see Population and trends) are among types assessed as VU, EN or CR in the EU Red List of habitats (Janssen et al. 2016).

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Conservation Actions

Hygrocybe mucronella is on the national Red Lists in multiple European countries (e.g. Austria, Germany, Netherlands, Norway and Switzerland; Senn-Irlet et al. 2007, Arnolds and Veerkamp 2008, Dämmrich et al. 2016, Demon and Krisai-Greilhuber 2016, Brandrud et al. 2021). The habitats of this species should be protected against destruction for the intensification of agriculture or development plans. The maintenance of semi-natural grasslands demands yearly grazing or mowing. If grazing by heavy animals destroys part of the soil, light animals like sheep should be recommended. Habitat conservation by governmental support to traditional agricultural practices is most important, this exists in many countries to maintain extensive areas of agricultural areas, and should be extended to larger areas than today. Forest management and protection are also needed, especially on calcareous soils, and mining and development projects should be avoided. Further ecological research is needed to clarify the nutrient strategy of grassland species, the habitat requirements and habitat exploitation of H. mucronella and habitat trends should be monitored. Management plans are also needed.

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Use and Trade

The species is not known to be used.

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Source and Citation

Kautmanova, I., von Bonsdorff, T., Mešić, A. & Jordal, J. 2024. Hygrocybe mucronella. The IUCN Red List of Threatened Species 2024: e.T228755008A247851678. .Accessed on 29 October 2024

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• Country occurrence