Hygrocybe canescens is a rare waxcap fungus in north western Europe and north eastern North America. The largest population is assumed to be in Europe, where it grows in old seminatural grasslands, a habitat which is strongly declining due to changing agricultural practices, development projects and pollution. Griffith et al. (2013) estimated a habitat loss of 90% over the last 75 years for the CHEG-fungi (grassland fungi of the groups Clavariaceae, Hygrocybe s.l., Entoloma and Geoglossaceae) as a whole in Western Europe (i.e. loss in seminatural grasslands, based on available information). 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). Also other sources point to a habitat loss in seminatural grasslands of roughly 1% per year in Europe over a longer time, although the data quality is not always very good. The decline in Europe is assumed to be more than 50% over the last 50 years because it grows in coast/lowland areas where the habitat loss has been very high (approximately three generations: one generation is assumed to be about 17 years). Habitat quality has also become impaired and the decline in population size over this time could be even higher because of this, strengthening the assumption of >50% population decline. This decline in habitat is ongoing and expected to continue. In northeastern North America the species occurs at least partly in forests where habitat loss is expected to be lower. GBIF lists totally 93 occurrences. There are about 50 known localities in Northern Europe (Norway: 18, Sweden: 15-20, UK: 12) and ca. 20 in North America. The total number of localities is expected not to exceed 1500 and the number of mature individuals per site is assumed to be less than ten. The species is assumed to have a population below 20000 mature individuals. This species meets the threshold for EN (A2c+3c+4c) for European populations. At a global scale the decline is assumed to be less, on the average 30-50% in 50 years (past, present and future). The species meets the IUCN criteria for VU (A2c+3c+4c).
Cuphophyllus is a genus separate from Hygrocybe s.str., and C. canescens (A.H. Sm. & Hesler) Bon clearly belongs here (Lodge et al. 2013). C. canescens from N Europe and N America seem to be conspecific based on molecular data (Ellen Larsson, Sweden, unpublished); the type is from N America. The taxonomic status of one GBIF occurence in Japan and one in New Zealand is uncertain; these could be other taxa and will not be further treated here. Synonymes: Hygrophorus canescens A.H. Sm. & Hesler, Hygrocybe canescens (A.H. Sm. & Hesler) P.D. Orton, Camarophyllus canescens (A.H. Sm. & Hesler) Singer
This is a rare fungus in NW Europe and NE North America. The largest population is assumed to be in Europe, where it grows in old seminatural grasslands, a habitat which is strongly declining due to changing agricultural practices, development projects and pollution. There is also a serious decrease in quality of the remaining habitats.
Hygrocybe canescens is distributed in north western Europe and north eastern America with its largest population in lowland/coastal parts of NW Europe. GBIF lists 93 occurrences from N Europe (UK, Sweden, Norway) and NE North America. There are about 50 known localities in Northern Europe (Norway: 18, Sweden: 12-15, UK: 12) and ca. 20 in North America (Eastern USA, Eastern Canada).
Totally less than 100 localities are known (GBIF 2019), about 70 in Europe and ca. 20 in N America. Seminatural grasslands are strongly declining. Griffith et al. (2013) estimated a habitat loss of 90% over the last 75 years for the CHEG-fungi (grassland fungi of the groups Clavariaceae, Hygrocybe s.l., Entoloma and Geoglossaceae) as a whole in Western Europe (i.e. loss in seminatural grasslands, based on available information). According to the Food and Agriculture Organization of the United Nations (FAO 2006), the area of grasslands in the EU declined by 12.8% over 13 years (1990-2003). In Sweden and Norway a decline of at least 50% is assumed the last 50 years for this species (http://artfakta.artdatabanken.se/taxon/794; https://www.artsdatabanken.no/Rodliste), especially because the species grows in lowland/coastal habitats. An assumption of an average habitat loss in European localities of at least 1% per year is therefore suggested for the assessment period, thus at least 50% over the last 50 years for European populations. The habitat quality of seminatural grasslands is also declining, strengthening the assumption of a population decline above 50%. More than 75% of the grasslands habitats are in an unfavourable conservation status, according to draft data provided by Member States under Article 17 of the Habitats Directive (http://ec.europa. eu/environment/nature/knowledge/ rep_habitats/index_en.htm#csa). This trend is ongoing and expected to continue in the future. The trend in N America is uncertain due to lack of data, but forest habitat decline over 50 years could be in the interval 10-20%.
Population Trend: Decreasing
Cuphophyllus canescens is an indicator of mycologically rich but nutrient-poor, semi-natural grassland (a member of the waxcap grassland assemblage), often on acid soil. This habitat, which may be of low conservation concern for its plant and animal diversity, is rapidly disappearing worldwide due to changes in land use (intensification of farming practice, eutrophication and increased use of fertilizers and pesticides). Halbwachs et al. (2018) suggested that these fungi are biotrophic endophytes or possibly mycorrhizal. The fruit bodies are short-lived (weeks), but the mycel is suspected to be longlived; >50-100 years.
In Norway and Sweden, practically all localities of the species are in grasslands, or grassy spots in coastal Calluna heath (Jordal et al. 2016, https://www.artportalen.se). In North America, the habitat information is scarce, but according to Hesler & Smith (1963) the species is growing on the ground under hemlock. Waxcaps are in N America generally found in forests or forest margins, preferrably under trees not forming ectomycorrhiza (Halbwachs et al. 2018), but grasslands could be an underestimated habitat due to little attention (Griffith et al. 2013).
Habitat destruction and abandoning are the main threats to seminatural grasslands. The most important process is probably withgrowing due to ceased grazing/mowing of old seminatural grasslands as part of intensification of agriculture. Further modern cultivation methods like use of fertilizers, pesticides and plowing. Also some places changed land use with the construction of roads, industrial areas, settlements etc. Decline is expected to continue, as the areas of seminatural grasslands are of little economic importance in modern agriculture. Most waxcap grasslands are among types redlisted as VU, EN or CR in the EU red list of habitats (Jansen et al. 2016). The quality of habitats is also decreasing. More than 75% of the grasslands habitats in EU are in an unfavourable conservation status, according to draft data provided by Member States under Article 17 of the Habitats Directive.
Site protection and management of habitats are very important conservation actions. The habitats should be protected against destruction due to intensification of agriculture or development plans. The maintaining of seminatural grasslands demands yearly grazing or mowing. If grazing by heavy animals destroys part of the soil, light animals like sheep should be recomended. Habitat conservation by governmental support to traditional agricultural practices is most important, this exist in many countries to maintain extensive areas of agricultural areas, and should be extended to larger areas than today. Suggested as a ‘priority species’ in Norway (Jordal 2013), and from december 2018 in process towards a decision.
Further ecological research needed to clarify resource relations of waxcaps. Management plans are needed. Habitat trends should be monitored.
The species is not known to be used.
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