• Proposed
  • Under Assessment
  • Preliminary Assessed
  • Assessed
  • NTPublished

Pleurotus rickii Bres.

Search for another species...

Scientific name
Pleurotus rickii
Author
Bres.
Common names
 
IUCN Specialist Group
Mushroom, Bracket and Puffball
Kingdom
Fungi
Phylum
Basidiomycota
Class
Agaricomycetes
Order
Agaricales
Family
Pleurotaceae
Assessment status
Published
Assessment date
2020-08-18
IUCN Red List Category
NT
Assessors
Bittencourt, F., Kossmann, T., Martins da Cunha, K., Drechsler-Santos, E. & Menolli, N.
Reviewers
Mueller, G.M.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/196135756/196846415

Justification

Pleurotus rickii is an edible species of mushroom growing on decaying wood. Although conspicuous, it has only been recorded 10 times since its description 100 years ago. It is known from Argentina and Brazil, but may also occur throughout the Yungas and in the Atlantic Forest in Misiones, Argentina and the humid Chaco in Argentina and Paraguay. Given the large area of potential suitable habitat, there are an estimated 1,000 sites where the species may be found, each containing up to 10 mature individuals. The total population size is estimated at 5,000 to 10,000 mature individuals, separated into two subpopulations. Most of the records are from the southern Brazilian Atlantic Forest, which is under an array of threats, including deforestation and land transformation. Other vegetation types where it likely occurs, e.g. the Yungas in Argentina, are also threatened, and the number of mature individuals in those habitats is expected to be rather small. Therefore, a population decline of at least 5% over 15 years (three generations) is suspected, and the species is assessed as Near Threatened C1.

Taxonomic notes

Pleurotus rickii was originally regarded by Rick (1907) as a new record of Armillaria procera for Rio Grande do Sul state, southern Brazil. Later, Bresadola (1920) revised the specimen and described it as P. rickii in honour of the mycologist.

Geographic range

The species is known from the southern Brazilian Atlantic Forest and the Yungas in Argentina. It may also occur in the Humid Chaco in Argentina and Paraguay. In Argentina it was recorded in Tucumán (Singer and Digilio 1952, Lechner et al. 2004); in Brazil it is known from in the southern and south-eastern regions of the country in the states of Rio Grande do Sul (Rick 1907, Bresadola 1920), Santa Catarina and São Paulo (Menolli et al. 2014).

Population and Trends

Pleurotus rickii is currently known at at least 8 sites. Although conspicuous, the species has been recorded few times (one or two records per site), even in intensively sampled areas and it is considered a rare species. There are only 10 records of the species, eight from the Atlantic Forest of Brazil and two from the Yungas of Argentina. In Brazil, it is expected to be found throughout the southern and south-eastern Atlantic Forest. In Argentina, it is estimated to occur throughout the Yungas and in the Atlantic Forest in Misiones. It may also be found in the Humid Chaco in Argentina and Paraguay. Given the large area of potential suitable habitat, there are an estimated 1,000 sites where the species may be found, each containing up to 10 mature individuals. The total population is estimated at 5,000 to 10,000 mature individuals, split into two subpopulations (Atlantic Forest and potentially Humid Chaco as one subpopulation; and the Yungas as another). The forests where the species is found are declining in area and quality due to continuing deforestation, increase in fire frequency and intensity, and impacts of climate change. The number of individuals are estimated to be smaller now than they were in the past, and the decline is predicted to continue into the future, with a suspected decline in population size of at least 5% over the next 15 years (three generations).

Population Trend: decreasing


Habitat and Ecology

The species is a saprotroph on dead trunks of angiosperms in certain Neotropical forests, including the Yungas, humid Chaco and south Atlantic Forest (Bresadola 1920, Lechner et al. 2004, Menolli et al. 2014).

Threats

The Atlantic Forest is regarded as one of the global biodiversity hotspots for conservation priorities due to their high diversity, endemism rates and habitat loss (Myers et al. 2000). The Yungas, although covering less than 2% of Argentina, still plays a major role in the biodiversity of the country, where about 50% of its species can be found (Brown and Grau 1993, Vides-Almonacid et al. 1998). About 300 km² of the Yungas are currently protected, but human occupation and land use and transformation to soybean fields continue to cause habitat loss and facilitating fire (Brown et al. 2002). In some areas, the loss reaches the rate of 100 km² per year (Brown et al. 2002). Both areas continue to be threatened with further decline due to land use changes, deforestation, and ‘savannization’ of tropical forests of South America due to climate change over the next decades (Salazar et al. 2007). The humid Chaco, where the species probably also occurs, has only 0.4% of its original area protected (Brown et al. 2006), and it also suffers from deforestation for agricultural land implementation (Boletta et al. 2006), with soybean cultivation being the greatest cause of cleaning in Argentina and Paraguay (Fearnside 2001, Kaimowitz and Smith 2001, Grau et al. 2005).

Conservation Actions

The main actions to prevent the continued decline of the species are the protection of its habitat by the implementation of Protected Areas and enforcement of public policies to recover secondary forests. Studies on the species commercial cultivation and viability may also help protect the species ex situ. Additional mycological surveys in other sites of Atlantic Forest, humid Chaco and the Yungas are needed to confirm its potential range and better understand its distribution. Revision of herbarium specimens may reveal additional records of this species and help clarify its distribution. As Pleurotus rickii is an edible species, studies about its life cycle, phenology, ecology and commercial cultivation should be carried, as this could help preserve the species ex situ.

Use and Trade

It is edible according to Singer and Digilio (1952), but whether it is actively traded is unknown.

Source and Citation

Bittencourt, F., Kossmann, T., Martins da Cunha, K., Drechsler-Santos, E. & Menolli, N. 2021. Pleurotus rickii. The IUCN Red List of Threatened Species 2021: e.T196135756A196846415. https://dx.doi.org/10.2305/IUCN.UK.2021-1.RLTS.T196135756A196846415.en .Accessed on 2 April 2022

Country occurrence