Cantharellus melanoxeros is a widely distributed European ectomycorrhizal species typically associated with beech and deciduous oaks. The conservation status of its most common habitat is reported under the EU Habitat Directive as “Unfavourable-Inadequate”. The main threat relates to declining habitat quality. The majority of mature individuals are found in Norway and Sweden where habitat is declining and the species is assessed as Near Threatened. The species is globally assessed as Near Threatened under criteria A2ce+3ce+4ce due to a suspected past and ongoing population reduction of more than 15% over three generations (50 years), due to habitat declines and the impacts of pollution (e.g. nitrogen deposition and use of fertilisers).

Cantharelus melanoxeros is restricted to Europe and mainly present in the Atlantic, Central European, and Alpine domains. Its geographic range extends from Spain to European Russia. So far it has not been reported in Portugal, Ireland, most of the Balkans, Moldova, Czechia, Poland, Belarus, two of the Baltic States, Ukraine and European Türkiye.

Although generally reported as rare, Cantharellus melanoxeros is possibly somewhat overlooked and its population size is likely to be well over 20,000 mature individuals. However, the species is in decline.

The species is predominantly western European, with a large number of individuals in France, Norway, and Sweden. Currently, C. melanoxeros is known from approximately 165 sites in Norway (GBIF.org 2021). In Sweden, about 100 sites were recorded between 1995-2020 (GBIF.org 2021). Populations are declining in both countries and the species is assessed as Near Threatened. In 2015, the reported number of known sites was about 300, of which nearly half were in France, where a decline over the last 30 years had been described (Fraiture and Otto 2015).

The most common habitat of C. melanoxeros is Asperulo-Fagetum beech forest (Natura 2000 habitat type 9130). The conservation status of this beech forest type in the EU is overall “Unfavourable-Inadequate” due to poor structure and function (habitat quality), and poor future prospects, and reflects inadequate forest management. In Sweden, this habitat is assessed as “Unfavourable-Bad” due to decreasing area, bad quality and bad future prospects (European Environment Agency, 2013-2018). In Norway, where most mature individuals are thought to be found, the species occurs mainly in Corylus or Corylus-Tilia forests on steep slopes. These forests are classified as Vulnerable due to the ongoing reduction in area (Artsdatabanken 2018). Given this past and ongoing decline of its habitat, both in terms of area and/or habitat quality, the population of C. melanoxeros is suspected to have declined and be declining by more than 15% over 50 years (three generations, Dahlberg and Mueller 2011).

Cantharellus melanoxeros is ectomycorrhizal with trees in the Fagaceae, typically Fagus sylvatica, Quercus robur, and Q. petraea. In Scandinavia and the UK, it also associates with Corylus avellana (Betulaceae), in France possibly also with Carpinus. There are a few observations under spruce (Fraiture and Otto 2015), probably mainly in Picea plantations in former deciduous forests.

Typical habitats include deciduous (e.g. together with Castanea, Tilia) and mixed forests (with Pinus). In Central Europe, it prefers warm sites. In more northern regions, it is found in boreo-nemoral oak forests. It avoids nitrogen-rich soils and is restricted to natural and near-natural forests.

The species is found in the following Natura 2000 habitats (codes): 9020, 9050, 9070, 9110, 9120, 9130 (Asperulo-fagetum beech forests, the most common habitat), 9150, 9160, 9170, 91A0, 9260 (Dalhberg and Croneborg 2003).

The main threats relate to commercial forestry (e.g. fertilisation, clear-cutting, logging and exotic tree plantations), poor management (e.g. cessation of grazing in mossy environments in Sweden), and airborne nitrogen deposition. Climate change is an increasing threat due to the unclear adaptive potential of host trees.

It is an edible species, but not much used. It is collected when encountered by mushroom pickers and occasionally sold on local markets, but its commercial value is low (Dalhberg and Croneborg 2003).

The species is included on Red Lists in several European countries; it is Vulnerable (VU) in Austria and Switzerland, and Near Threatened (NT) in Sweden, Norway and Russia (Senn-Irlet et al. 2007, Svetasheva 2014, Dämon and Krisai-Greilhuber 2017, Artsdatabanken 2018, SLU Artdatabanken 2020). For the sites that are within the Natura 2000 network, appropriate forest management plans can play a role in improving the conservation status of the species. For the localities outside the protected Natura 2000 network, improving European-level information on forest status will allow a more precise assessment of the situation and the design of appropriate policy responses. Individual mycelia of ectomycorrhizal fungi persist with their host trees. Therefore, site protection, along with engagement with site managers to ensure long-term management is needed to maintain appropriate habitat with required host trees.

Continuous, long-term monitoring of Cantharellus melanoxeros is recommended. Searches for the species in countries that have not yet recorded this species should be conducted to get a clearer view of the full distribution; and this could include using soil and root tip sampling techniques.