R-L categories correct, but text here does not match final assessment. Updated version will be published in IUCN´s Red List June or Nov 2019.
Pseudotricholoma metapodium is rare and strongly confined to semi-natural grasslands in Europe, especially in lowland/coastal areas. 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; where also Pseudotricholoma metapodium belongs) as a whole in Western Europe. These habitats are declining and getting bad quality due to changing agricultural practices, development projects and pollution (nitrogen deposition). A total of ca. 400-450 localities (>800 occurrences in GBIF) is known in Europe, of which ca. 90% (350-400) are in Sweden, Norway and Great Britain. Switzerland has 19 loc. after 1990, Denmark 12, and there is further information on 1-10 in each of Austria, Slovakia, Germany, Czeck republic, Finland, France, Italy and Spain. The species is EN in three countries, CR in two and VU in one. The largest populations (Norway + Sweden) are assumed to have experienced a decline of 50-80% in the past and present - and also possible future - three generations. The species is in many countries known to occur mainly in the most species rich/high quality “waxcap grasslands”. Many of its localities seem to have very few mycelia/individuals. There is information of a combined habitat loss and decreased habitat quality of >50% in West European lowlands the past 50 years. As this species is additionally probably responding to some features related to high age and high quality of seminatural grasslands, its population decrease is probably well over 50% in the past 50 years. The species is assumed to have a population of more than 20000 mature individuals, and the A-criterion is thus appropriate. The species meets the threshold for EN (A2c+3c+4c) in Europe (population decline >50% in three generations), which is also assumed to be the total area of the species, thus the global status is the same.
This species has long been placed in the genus Porpoloma Singer. Recent molecular studies suggest a placement in the genus Pseudotricholoma (Singer) Sánchez-García & Matheny, as P. metapodium (Fr.) Sánchez-García & Matheny is not closely related to the type species of Porpoloma, P. sejunctum Singer. Pseudotricholoma metapodium is normally easily recognized but be aware of Lepista luscina. It has also been confused with Hygrocybe ovina.
Pseudotricholoma metapodium is only known from Europe, and strongly confined to old seminatural grasslands, most often with many other redlisted fungi. In large parts of its distribution, this species is found in small isolated grassland patches hosting very few individuals. These habitats are strongly declining due to agricultural intensification (plowing, use of fertilizers and pesticides), development projects, and aerial nitrogen deposition. It is red-listed in high categories in at least 6 countries: Denmark (CR), Germany (CR), Finland (EN), Norway (EN), Sweden (EN) and Switzerland (VU).
Endemic to Europe. Broadly distributed in temperate areas, but the main population around the North Sea (Norway, Sweden, UK), probably with oceanic tendency. Scattered and rare in all its distribution range, but less rare in Norway, Sweden and UK. Mainly in the lowlands, but in Scandinavia rarely in middle boreal vegetation zone and in the Swiss Alps up to 2020 m asl.
A total of ca. 400-450 known localities is estimated in Europe, of which ca. 90% are in Sweden, Norway and Great Britain. Switzerland har ca. 19 loc. after 1990, Denmark has 12 loc., and there is further information on 1-10 in each of Austria, Slovakia, Germany, Czeck republic, Finland, France, Italy and Spain. The species is EN in three countries, CR in two and VU in one. The largest populations (Norway + Sweden) are assumed to have declined 50-80% in the past and present - and also possible future - three generations. The species is in many countries known to occur mainly in the most species rich/high quality “waxcap grasslands”. Its populations are decreasing due to loss of habitat, and many of them have very few mycelia/individuals. Semi-natural grasslands are known to have strongly decreased in Europe. There is information of a combined habitat loss and decreased habitat quality of >50% in West European lowlands the past 50 years. As this species is probably responding to some features related to high age and high quality of seminatural grasslands, its population decrease is probably well over 50% in the past 50 years.
Population Trend: Decreasing
Primarily in non-fertilized dry grasslands and natural pastures. In Spain, it also occurs in periodically cut Pteridium stands and grassy forest clearings, on acid soil. In Norway strongly confined to old seminatural grasslands; of 189 observations, 94,2 were in seminatural grasslands, only 1,6% in forest-like habitats, and the rest in grassy habitats resembling seminatural grasslands (Jordal et al. 2016). Similar habitat requirements in other countries. Its main distribution is in the lowlands, but it is found up into the middle boreal vegetation zone in Norway (ca. 770 m) and 2020 m in the Swiss Alps.
This species has undergone a strong regression due to loss of habitat. Natural pastures and nutrient poor grasslands have disappeared to large extent in Europe. Thus, P. metapodium is sensitive to changes in traditional use of seminatural grasslands, e.g. fertilization. To a smaller scale, cessation of tratidional cutting Pteridium fields is a secondary threat in Northern Spain. Development projects and nitrogen deposit can also be threats.
Maintenaince of traditional use of semi-natural grasslands and protection of sites where it occurs against change in use of area (e.g. development projects). 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 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. Management plans are needed. Proposed as a national priority species in Norway (Jordal 2013).
Research into ecological requirements and trophic form. Management plans are needed. Habitat trends should be monitored.
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