- Scientific name
- Microglossum atropurpureum
- (Batsch) P. Karst.
- Common names
- Dark-purple Earthtongue
- purpurfarvet jordtunge
- Schwarzrote Blasssporerdzunge
- Purperbruine aardtong
- purpurbrun jordtunge
- Schwarzrote Erdzunge
- IUCN Specialist Group
- Cup-fungi, Truffles and Allies
- Assessment status
- Assessment date
- IUCN Red List Category
- IUCN Red List Criteria
- Jordal, J.
- Ainsworth, A.M. & Mešić, A.
In Europe Microglossum atropurpureum
is a species of mainly calcareous seminatural grassland, mostly in the lowlands. These habitats are declining due to changing agricultural practices, development projects, mining and pollution (airborne nitrogen deposition). In North America the species mainly grows in forests, habitat trends here are unknown. GBIF lists about 1500 occurrences (under two names) of which about 100 in North America. In Europe we assume a total habitat loss of 30-50% over the last 50 years (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, strengthening an assumption of probably near 50%. This decline in habitat and populations is ongoing and expected to continue over the next 50 years. The species is assumed to have a population of more than 20,000 mature individuals. In Europe, the population decline is assumed to be 30-50% in 50 years (past, present and future). At a global scale (i.e. Europe + North America) the decline is also assumed to be above 30% taking into account the much smaller population reported in North America (GBIF 2019). The species meets the threshold for VU (A2c+3c+4c) both globally and for Europe.
The name Geoglossum atropurpureum
(Batsch) Pers. is used in many countries. Based on molecular data this is not a Geoglossum
, it is not even in the new class Geoglossomycetes but in the Leotiomycetes (Ohenoja et al
. 2010, Schoch et al
. 2009, Hustad et al
. 2013). The proper generic name still remains unclear (Thuemenidium atropurpureum
(Pers.) Kuntze, or Microglossum atropurpureum
(Pers.) Sacc.; Ohenoja et al
. 2010, Hustad et al
. 2013), but Microglossum
is used here. The taxonomic status of GBIF occurrences in North America is uncertain but accepted here for the time being. Provisionally, a few occurrences from Japan and New Zealand are regarded as a probably related species.
The species is known from Europe and North America. In Europe it occurs in many countries in the lowlands and rarely up to subalpine areas. The main distribution in Europe is in the northwestern, coastal areas. The eastern limit is uncertain due to lack of data. In Scandinavia the species is found most often in the southern parts of Norway and Sweden, up to southern to middle boreal vegetation zone, and rarely in the northern boreal zone. The species is mentioned from North America (e.g. Grund and Harrison 1967, GBIF 2019), Japan (Imai 1941, GBIF 2019) and New Zealand (GBIF 2019). There is need of molecular methods to confirm these data. Currently we accept the occurrence in North America, but regard the eastern occurrences as probably related species, like the situation in other earth tongues (see e.g. Hustad et al
Population and Trends
According to GBIF (2019) there are >1000 occurrences from Europe and <100 from North America. Based on available information on trends in European seminatural 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. A strong decline over 20 years is documented in Sweden (Nitare 1988). 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 habitat quality of seminatural grasslands is also declining, strengthening the population decline. More than 75% of the grasslands habitats are in an unfavourable conservation status (http://ec.europa.eu/environment/nature/knowledge/rep_habitats/index_en.htm#csa). This trend is ongoing and expected to continue in the future. A smaller amount of the European population occurs in calcareous forests with a lower decline in the same period, maybe 15-20%. The trend in North America is uncertain due to lack of data about the forest habitats there. The habitat loss in Europe is probably 30-50% in grasslands, and >30% in the total population. Over the whole distribution range (taking into account the part of the population in forest) we assume a total habitat loss and population decline of 30-50% over the last 50 years. This trend is ongoing and expected to continue in the future.
Population Trend: decreasing
Habitat and Ecology
The major population of Microglossum atropurpureum
grows in mycologically rich but nutrient-poor semi-natural grasslands, often (but not always) on calcareous soil. Semi-natural grasslands are rapidly disappearing due to changes in land use (see Threats and Population). In Norway, most localities of the species are in semi-natural grasslands and rather few in rich/calcareous forests (N=235: 83.0% semi-natural grasslands, 10.2% rich forests, and the rest mainly in related grassland types like unmanured parks and lawns; Jordal et al
. 2016), and similar patterns are found in other European countries. In North America it is known from different forest types, but little information is available. The nutrient strategy is unknown but it could have some kind of biotrophy or mycorrhiza, like waxcaps (Nitare 1988).
Habitat destruction and abandonment are the main threats to seminatural grasslands including the calcareous ones. The most important process is probably overgrowing 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 ploughing. Also in some places changed land use with the construction of roads, industrial areas, settlements etc. Airborne nitrogen deposition is another significant threat. The decline is expected to continue, as at least the areas of seminatural grasslands are of little economic importance in modern agriculture. Most CHEG grasslands (see Population) are among types assessed as VU, EN or CR in the EU Red List of habitats (Janssen et al
. 2016). Calcareous forests are also subject to decline at least in Europe. The threats in North America are unclear, in part due to uncertainty regarding its preferred habitats and their trends.
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 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. It is a category II protected species in Estonia. It is proposed as a priority species in Norway (Jordal 2013).
Further ecological research is needed to clarify the nutrient strategy of grassland earth tongues. Management plans are needed. Habitat trends should be monitored.
Use and Trade
The species is not known to be used.
Source and Citation
Jordal, J. 2019. Microglossum atropurpureum. The IUCN Red List of Threatened Species 2019: e.T147296771A147904382. https://dx.doi.org/10.2305/IUCN.UK.2019-2.RLTS.T147296771A147904382.en
.Accessed on 1 February 2023