Assessment Notes

Justification

Wrightoporia araucariae is currently known from two localities, both in southern Brazil. The species is known to grow only on Araucaria angustifolia, an economically important and emblematic tree, and is expected to be found throughout its host's distribution, in southern/south-eastern Brazil, north-eastern Argentina and in parts of Paraguay. However, it has not been found in these areas. It is likely a rare species, as areas where its host, A. angustifolia, is abundant are among the most surveyed areas of the Atlantic Forest, such as the São Joaquim National Park, where in ca. 9 years of intensive sampling, only one specimen has been found. Its host species, A. angustifolia, is assessed as CR on the IUCN Red List (Thomas 2013), having lost about 97% of its original cover in the last 100 years, mainly due to logging, a decline that is still ongoing. The total population size of W. araucariae is estimated at 8,000-10,000 mature individuals, distributed in around 500 sites, each with up to 20 mature individuals. 

The species is threatened by the loss of its host. Although A. angustifolia is legally protected now (Brasil 2008), the forests where the species occurs (Araucaria Moist Forests) continue to suffer a decline (Global Forest Watch 2020). Additionally, only a small part of the Araucaria forests are in conservation areas (Indrusiak and Monteiro 2009), and studies suggest that climate change will complement other ongoing threats, and by 2070 the species could be restricted to highland microrefugia, of which only 2.5% are in conservation areas (Wilson et al. 2019, Castro et al. 2020).

The species is assessed as Critically Endangered under criterion A3c, having an estimated population loss of up to 90% in the next 50 years (three generations).

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Geographic range

The species is currently known only from southern Brazil in São Francisco de Paula National Forest, in Rio Grande do Sul state, and São Joaquim National Park, in Santa Catarina state. The species has only been found growing on Araucaria angustifolia, an economically important and emblematic tree. This plant used to have an abundant and widespread distribution in regions with subtropical climates in southern/south-eastern Brazil, north-eastern Argentina and parts of Paraguay. However, it now has a very restricted and fragmented distribution, being mostly concentrated in southern Brazil, having lost about 97% of its original cover. Wrightoporia araucariae is expected to be found throughout its host’s distribution, and is likely to have declined in line with habitat loss.

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Population and Trends

Wrightoporia araucariae is currently known from two localities and 5 collections. It is likely a rare species, as areas where its host, Araucaria angustifolia, is abundant such as the São Joaquim National Park and the São Francisco de Paula National Forest, are among the most surveyed areas of the Atlantic Forest. Only 5 specimens have been recorded during a decade of intensive sampling.

Its host, A. angustifolia, is assessed as CR on the IUCN Red List (Thomas 2013), having lost about 97% of its original cover in the last 100 years, mainly due to logging, a decline that is still ongoing. 

The total population of W. araucariae is estimated to be 8,000-10,000 mature individuals, distributed over approximately 500 sites, each with up to 20 mature individuals. Population size is inferred to have declined at least 50% over the past 50 years mainly due to the extensive loss of its host species (Sevegnani et al. 2013). An ongoing further decline of 80-90% is suspected, as studies suggest that its host could be become restricted to isolated highland microrefugia due to climate change which will complement other ongoing threats (see Wilson et al. 2019, Castro et al. 2020).

Population Trend: decreasing

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Habitat and Ecology

Wrightoporia araucariae is a saprotrophic wood-decaying fungus. It has been found exclusively on dead logs of Araucaria angustifolia, hence its name. Its host is restricted to regions with subtropical climate in southern/south-eastern Brazil, as well as north-eastern Argentina and parts of Paraguay. However, its host has lost most of its area, and currently is mostly found in southern Brazil. In other regions, the host occurs sporadically in high altitude environments throughout its former range, but the fungus has not been reported from these regions.

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Threats

The species is threatened by the loss of its host, Araucaria angustifolia. This coniferous tree is assessed as CR on the IUCN Red List, as it has lost 97% of its original cover in 100 years, a decline that remains ongoing today. An extensive amount of this loss took place in the last 50 years, due to land conversion for farming and plantations as well as logging activities. Although A. angustifolia is legally protected now (Brasil 2008), the forests where the species occurs (Araucaria Moist Forests) are still suffering a continuing decline (Global Forest Watch 2020). Additionally, only a small part of the Araucaria forests are in conservation areas (Indrusiak and Monteiro 2009), and studies suggest that, due to climate change, by 2070 the species could be restricted to highland microrefugia, of which only 2.5% are in conservation areas (Wilson et al. 2019, Castro et al. 2020).

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Conservation Actions

The main action to preserve the species is the protection of its host. This should include enforcing policies already assured by law, restoration of Araucaria forests, and creation of new conservation areas to protect the probable sites which the species will be restricted to in the future. Additionally, more surveys are needed in other areas with Araucaria to confirm this specific species' range and ecology (in particular host-specificity). Also, there are no DNA sequences available for the species, and no phylogenetic studies have been conducted to test its phylogenetic position, so these should be conducted.

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Use and Trade

No use/trade is known.

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Source and Citation

Robledo, G., Drechsler-Santos, E.R., Kossmann, T., Bittencourt, F. & da Cunha, K.M. 2020. Wrightoporia araucariae. The IUCN Red List of Threatened Species 2020: e.T187000299A187004575. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T187000299A187004575.en .Accessed on 3 February 2024

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• Country occurrence