Assessment Notes

Justification

The Fen Puffball is a small puffball with wide distribution range in Northern Hemisphere, associated with mosses and growing in one of the most vulnerable and declining habitats – alkaline and neutral fens, bogs, mires and wet meadows. These habitats are among the most threatened type of terrestrial habitats due to hydrological system modifications, surface water and air pollution (eutrophication), natural succession and erosion, agriculture intensification, silviculture and forest management, mining (peat extraction) and urbanization. Thus, the species is threatened by habitat loss and degradation. Its population decline has been widely reported.
It is assessed as VU A2c+3c+4c.

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Geographic range

The species is known from the Northern Hemisphere: Europe (lowlands, lower mountain regions, seldom above 1200 m a.s.l, but also in the Alps up to 2250 m a.s.l.) and Asia (Altai, Siberia, Himalaya up to 3650 m a.s.l., India). There are also few published records from North America (Canada, USA; Fraiture and Otto 2015). However, no American records exist in the internet accessible databases (Mycoportal, iNaturalist, Mushroom Observer, USDA ARS, Canada’s Species, GBiF, NCBI, UNITE). Thus, it is assumed that the species occurs at present in Eurasia.

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Population and Trends

According to Fraiture and Otto (2015), the number of currently known sites in Europe is about 150. A decrease in frequency has been recorded in Czechia, Estonia, Finland, France, Germany, Poland and Sweden over the last 50 years. In Poland, 11 localities of the species are known; all but two were found before 1972 (Wojewoda 2002, Stastińska 2011, Kujawa et al. 2015). In Great Britain, there are currently 5 sites recorded over the past 30 years which equates to 50 mature individuals. The expected total UK population is <250 (Lost and Found Fungi Project 2018) and it was assessed as EN based on IUCN criterion D (Smith et al. 2016). On the distribution map of fungi in Germany, 32 localities (10 km x 10 km squares) are indicated (German Mycological Society 2018). According to Rebriev and Dvadnenko (2017) the species was found in Russia in the region of Altai, Crimea and Lake Baikal. Two Russian localities are also indicated in the GBiF database (one at Lake Baikal and the second on the coast of the Sea of Okhotsk). The GBiF database cites 431 localities of this species altogether, however, only 194 of them come from the last 30 years and 86 from the last 10 years; a great majority of the records come from Sweden. There are probably no current records of this species in North America, although it was reported in Canada in the past (Kreisel 1967). The species is included in Red Lists of Austria, Czechia, Estonia, Finland, France, Germany, Montenegro, Norway, Poland, Serbia, Slovakia, Sweden and Switzerland. It is protected by law in Finland and Poland.

The decline in species population size is correlated with a decline in its specific habitat area and quality.  Mires, bogs and fens are wetland habitats with a high water content governing many ecological processes that structure their characteristic communities. Thus, their hydrological balance is easily disturbed by increased drainage caused by human activities. Furthermore, mire habitats have been widely destroyed or greatly altered in many areas by the extraction of peat. Extraction of peat and conversion of natural mire habitats to productive agricultural and forestry land have been the main reasons for the decline of mire habitats during recent and more long-term historic times and this decline is still continuing. In EU countries, all but two of the 13 mire habitat types (85%) are threatened, and this is the highest percentage of threatened habitats in all terrestrial and freshwater groups (European Red List of Habitats 2016). Joosten (2009) estimates the total loss of peat lands in Europe as nearly 60%, but the percentage varies across the continent, e.g., 20% in Norway and Sweden and 44% in Nordic Baltic countries (Barthelmes et al. 2015). The distribution of peatland in Europe is strongly imbalanced, with much more peatland occurring in the north than in the south, roughly reflecting the influence of temperature and rainfall, with less peatland occurring where summer temperatures are higher and rainfall is lower (Moen et al. 2017). Thus, the threat of habitat loss, degradation and fragmentation, resulting in the Bovista paludosa population decrease and fragmentation, is also uneven.

Although the decline in these habitats in Asia have not been quantified, they face the same threats. 

Thus, the conservative estimate of the habitat loss for Bovista paludosa exceeds 30%; the rareness of this species and its dependence on the continuously declining habitat (both in the area and in quality) imply that B. paludosa has undergone a population decrease of a similar magnitude during the last 30 years, with this trend expected to continue into the future.

Population Trend: decreasing

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Habitat and Ecology

It is a saprotrophic species, frequently growing among mosses, solitary or in small groups in a rather wide range of wet mossy habitats (Wojewoda 2002, Fraiture and Otto 2015). It occurs most often in alkaline to neutral fens, bogs and mires, wet meadows including boggy peat meadows, wet heaths, sometimes in forest meadows, from June to October. The species avoids oligotrophic and strongly acid mires. Many of the species habitats are covered with the Natura 2000 network of protected areas. These include Molinia meadows on calcareous, peaty or clayey-silt-laden soils (6410), Active raised bogs (7110), Transition mires and quaking bogs (7140), Fennoscandian mineral-rich springs and springfens (7160), Calcareous fens with Cladium mariscus and species of the Caricion davalliance (7210), Alkaline fens (7230), Alpine pioneer formations of Caricion biciloris-atrofuscae (7240). 

The species grows on organotrophic substrates (peat), it prefers clearly basic pH (acid sites are exceptional) and low (oligotrophic) to moderately low (mesotrophic) nitrogen content. The species mainly occurs in natural and near-natural habitats, less often in semi-natural ones (extensively used meadows). Thus the fungus is a good indicator for undisturbed or only weakly disturbed fens and mires (Fraiture and Otto 2015).

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Threats

The species occurs in one the most threatened type of terrestrial habitats – in alkaline and neutral fens, mires and bogs. The habitat is vulnerable to hydrological system modifications, surface water and air pollution (eutrophication), natural succession and erosion, agriculture intensification, silviculture and forest management, mining (peat extraction) and urbanization. These sites are also very sensitive to climate change, especially to increasing droughts. In Europe, large areas of peatland have been drained. Thus, the species is threatened by habitat degradation and loss.

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Conservation Actions

The species can be protected through the conservation of its habitat and preventing the degradation of sites of actual and potential occurrence. This includes, e.g., preventing changes in water regime, avoiding intensification of agriculture and silviculture practices in the neighbouring areas, control over peat extraction, active prevention of the forest succession and erosion, control over the practices leading to eutrophication, etc. Designating key sites for protection is recommended.

B. paludosa is legally protected in Finland and Poland.

Research needed: Inventory studies and monitoring of known sites.

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Use and Trade

The species is of no interest for use and trade.

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Source and Citation

Kałucka, I.L. 2019. Bovista paludosa. The IUCN Red List of Threatened Species 2019: e.T125433484A125435455. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T125433484A125435455.en .Accessed on 3 February 2024

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• Country occurrence