Hygrocybe aurantiosplendens is a typical representative of the rich funga of old, unimproved grasslands, a habitat type that is decreasing rapidly in all of Europe. It occasionally grows also in scrub and calcareous forests on moist to dry, base-rich soils. The species is very striking by its size and bright orange basidiocarps and is usually well distinguishable from related species. It is almost only known from Europe, with very few localities in western Asia. In Europe H. aurantiosplendens is widespread, but rare to very rare everywhere (Boertmann, 2010) and decreasing, reflected by its classification in many national and regional Red Lists.

Based on the continuing and projected decline of the global populations of approximately 30-50% in three generations (50 years), Hygrocybe aurantiosplendens is preliminary assessed as Vulnerable based on A2c+3c+4c.

The taxonomic status of collections from N America (GBIF 2021) and Russian Far East (T. Svetasjeva pers. comm.) is uncertain, and they are here regarded as probably related species.

Widely distributed in Europe. The species is most frequent in Northern Europe (Scandinavia, Great Britain) and more rare in the south (here often in mountain regions). For data under this name from N America and Russian Far East: see under Names and taxonomy.

Hygrocybe aurantiosplendens is widespread in Europe, but rare to very rare everywhere (Boertmann 2010) and decreasing. The largest populations seem to be in Scandinavia and Great Britain. The total number of individuals is unknown. In view of the strong decrease of unimproved grasslands in the last 50 years (estimated three generations of this fungus), the number of individuals have decreased by at least 30%, possibly near 50%. The decline is reflected in the position of H. aurantiosplendens on many national Red Lists,  e.g. Endangered in Denmark, Finland, parts of France, Poland; Vulnerable in Austria and Germany; Near threatened in the Netherlands, Norway, Sweden. The decrease is still continuing.

Hygrocybe aurantiosplendens is a characteristic species of old, unimproved, low productive grasslands on loamy, weakly acid to basic, often calcareous soils. It occurs from sea level up to the alpine zone (2500 m in the Alps), but is not found in the alpine zone in Norway. It occasionally grows also in scrub and calcareous forests on moist to dry, base-rich soils. In Norway, about 20% of all records are from calcareous forests, the rest mainly from open grasslands (Jordal et al. 2016). Like other waxcaps, the species lives probably in biotrophic association with herbaceous plants, but details are unknown (Halbwachs et al. (2018).

Threats are grassland improvement (fertilizer application and soil disturbance) for agro-industry farming, abandoning of low productive grasslands, and forest plantations on poor grassland sites. Moreover the species is vulnerable for acidification and nitrogen deposition (Arnolds 2015).

The most important action will be conservation of sites with rich populations of Hygrocybe aurantiosplendens as nature reserves; continuation of traditional management: mowing and removal of sward or/and grazing in low densities without fertilizer application. 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 agricultural areas, and should be extended to larger areas than today. The species is a representative of a rich funga with many more rare and threatened species; therefore its protection will be beneficial to many more threatened fungi (Boertmann 2010; Arnolds 2015). There is a conservation action plan for this species in Sweden (Jordal 2011).

More detailed research on habitat requirements and habitat exploitation of H. aurantiosplendens would be useful. The habitats should be monitored.

No use or trade is known.

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