Cortinarius viridans is a strictly Mediterranean ectomycorrhizal fungal species with conspicous large sporocarps, apparently with a narrow-endemic local distribution, being restricted to montane forests of Cyprus, where the species occurs in association with the endemic Cyprus cedar. Here, Cyprus cedar is treated as a subspecies of Lebanon ceder, Cedrus libani var brevifolia which is assessed as VU on the IUCN global redlist, based on its very small, geographically restricted and decling populations which makes it vulnerable to stochastic events. The small Cyprus cedar forest patches currently comprised of less than a dozen fragmented small populations in the Paphos forest, between 900 and 1 600 a.s.l. and may be threatened by forest fires and climatic changes.
Cortinarius viridans is estimated to have a total population of <1 000 IUCN-individuals and an area of occupancy of < 20 km2. Hence, the species qualifies to be red-listed as VU, based on a very small population restricted to a small area (D1 and D2).
Cortinarius viridans was described as new species in 2021, based on a monographic treatment of sect. Leprocybe in Europe, including extensive sampling in the Mediterranean region (Bidaud et al. 2021, cfr. also Ammirati et al. 2021). The species is a close sister species to the frondose/Abies forest associate C. melanotus.
Cortinarius viridans is a Mediterranean species with a local endemic distribution, restricted to the endemic Cyprus cedar small forest patches of Troodos mountains at Cyprus. These small Cyprus cedar forest elements with its associate Cortinarius viridans are vulnerable to stochastic events, and are now apparently seriously threatened by less rainfall, more forest fires and global warming.
Cortinarius viridans is so far known only from a handful of collections in Cyprus cedar forests in the Troodos mountain range of Cyprus, being apparently restricted to a narrow altitudal range (900 – 1 600 m asl) in the western part of Cyprus (Bidaud et al 2021). The species belongs to section/subgenus Leprocybe, a group which is now well-studied in Europe, with a recent monograph based on morphological and extensive fylogenetical data including the Mediterranean regions (Bidaud et al. 2021, cfr. also Ammirati et al. 2021). It is thus unlikely that this species is much overlooked. However, a wider, Mediterranean distribution associated also with Cedrus libani, cannot be ruled out.
The species is so far known from 5 sites in montane Cyprus (Bidaud et al. 2021). Its ectomycorrhizal host tree, the Cyprus cedar, occupies a small area within the altitudal range of 900 – 1 600 m asl., and the real, total number of sites of C. viridans is estimated to not exceed 20 sites, each estimated to have fewer than 5 genetically unique fungal corresponding to less than 1000 fungal individuals according to IUCN standards (Dahlberg & Mueller, 2011), with an area of occupancy of < 20 km2. The Cyprus cedar forests were formerly almost extinct, but was locally re-planted, and the re-established forest patches are apparently at the moment not declining, but are very vulnerable to stochastic events, due to the extremely small and geographically restricted population. Based on this, its associate C.viridans is assessed as VU according to the D1 (<1 000 ind.) and the D2 (AOO < 20 km2) criteria. If the conditions for Cyprus cedar forests start to detoriate, the red-list status for C. viridans will become significantly worse.
Population Trend: Uncertain
Cortinarius viridans is a Mediterranean species, recorded only from Cyprus cedar forest fragments in montane Cyprus. The species is a putative ectomycorrhizal associate with Cyprus cedar, Cedrus brevifolia (or Cedrus libani var. brevifolia). According to present knowledge, C. viridans is endemic to Cyprus, and this seems so far to be the only documented endemic Basidiomycota with an endemic tree host in the Mediterranean region (Bidaud et al. 2021). The small Cyprus cedar forest patches are currently comprised of less than a dozen fragmented small populations in the Paphos forest, between 900 and 1 600 a.s.l. (Hab. type 9590, European Commission DG Environment, 2007) and may may also be restricted to serpentine and igneous substrates.
Cortinarius viridans and its host, the Cyprus cedar, occupies a very small area, and is vulnerable to stochastic events. Although the small Cyprus cedar forests at the moment do not seem to be seriously declining, some dieback has been observed, probably due to long-term decrease in rainfall. Furthermore, in the future, the Cyprus cedar and its associate, C. viridans may be threatened by forests fires and climatic changes, seriously affecting the altitudal forest zonation of the Cyprus mountains (Christou & Garnder 2019; see also IUCN global redlist assessment of Cedrus libani var. brevifolia). Based on some studies and technical reports, Cyprus cedar forests are expected to be severely threatened during the first half of the 2000 century, as a result of reduced rainfall and climate warming (see Linares et al. 2011; Shoukri and Zachariadis 2012).
To prevent decline and fragmentation of the Cyprus cedar forests with good habitat quality, it is important to set aside reserves with a strict conservation, preferentially also try to restore/establish some new sites within the optimal altitudal zone (which may shift upwards in the mountain zonation with global heating).
More surveying and monitoring of C. viridans are needed, as well as monitoring of the status of montane forests with the endemic Cyprus cedar Cedrus brevifolia.
No use or trade is known.
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Linares, J.C., Tíscar, P.A., Camarero, J.J., Taïqui, L., Vinegla, B., Seco, J.I., Merino, J., Carreira, A. 2011. Tree growth decline on relict Western-Mediterranean mountain forests: Causes and impacts. In: Forest Decline: Causes and Impacts, pp. 1–20.
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