Assessment Notes

Justification

This species is so far endemic to Brazil, found only in the Brazilian Amazon Forest. The species was found first, in 2012, in white-sand forest (“campinarana”) in Acre State and then in terra firme forest in Amazonas State. There are few records since its description, even though several field trips have been carried out in Amazonia. While the species appears to rare, given that it has been recorded in both white-sand and terra firme forests, this species may have a wide distribution in the Amazon basin. Although it seems to be a rare species, becoming even rarer with the continued loss and degradation of the habitat in the Amazon Forest due to human activity and climate change, its saprophytic condition in a diversity of habitats makes it difficult to understand its environmental requirements. Consequently, its habitat preferences and distribution are unclear, making it difficult to estimate its population size and trends or how threats affect the species. As there is scarce records of the species so far, it is assessed as Data Deficient as it could warrant a listing under any category from Least Concern to Critically Endangered.

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Geographic range

This species is so far endemic to Brazil, found only in the Brazilian Amazon Forest. The species was found first, in 2012, in white-sand forest (“campinarana”) in Acre State and has also been recorded in terra firme forest in Amazonas State. In this way, as rare as it may seem, it is likely that the species may have a wide distribution in the Amazon basin.

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Population and Trends

It is an easily recognised species, different from all described Geastrum since it has an elongated and ramified pseudostipe and exoperidium with a densely verrucose surface. Since 2012, just one specimen has been found, in Ducke Reserve in 2018, one of the most sampled areas within the Brazilian Amazon, with 7,306 specimens of fungi deposited in Brazilian Fungaria. Despite its remarkable morphology, and that several expeditions in the Brazilian Amazonian Forest have been carried out during this period, including by specialists in gasteroid fungi, no additional collections have been found. Therefore, G. verrucoramulosum can be considered as a rare fungus, even with a putative broad distribution in Amazonian Forest.

The Amazon Forest is undergoing rapid deforestation and facing increased fire frequency and intensity, following years of decline (INPE 2020). The species is suspected to undergo a population decline of up to 15% in the next 20 years (three generations). The population decline was suspected in light of the loss of suitable habitat (Zhang et al. 2015) and the putative influence that habitat degradation has on species occupation in a given environment (Berglund and Jonsson 2001, Haddad et al. 2015). Although it seems to be a rare species, becoming even rarer with the continued loss and degradation of the habitat in the Amazon Forest due to human activity and climate change, its saprophytic condition makes it difficult to understand its environmental requirements and, consequently the habitat preferences and its distribution are unclear, making it difficult to estimate its population size and how threats in fact affect the species.

Population Trend: decreasing

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Habitat and Ecology

This saprotrophic species is terrestrial and grows on soil in clusters of basidiomata, found both in an open forest composed mainly of shrubs on white-sand soil (called ‘campinarana’) and in upland dense forest on clay soil, during the rainy season. So far, the species is restricted to the Amazon Forest.

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Threats

The Amazon Forest has been going through intensive deforestation (e.g. through logging and fire) and other anthropogenic threats, which will cause severe biodiversity losses in a long-term period, especially as a consequence of habitat loss and reduction of habitat quality (Swann et al. 2015). The main threats are due to the expansion of road construction, hydroelectric dams, and deforestation for cattle and agriculture (monoculture) (MapBiomas 2021). In addition, the sites where the species were found in Amazonas, even being protected areas, are located in the metropolitan region of Manaus, so there is a great urban expansion pressure (Ramos et al. 2018). The area in Acre is located in a deforestation hotspot in Amazonia, along the major roads known as the Arc of Deforestation, where the rate of destruction is faster even inside of protected areas (Finer et al. 2020). To date, c.18% of the region’s tropical forest has been cleared, with average annual losses in the last decade of 1.8 million hectares per year (INPE 2020). The development of infrastructure is also recognized as a contributing driver of this forest loss. Lack of enforcement of laws and policies for effective management of the Amazon is contributing to the loss and degradation of habitat.

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Conservation Actions

All known records near Manaus were collected in protected areas. Thus, the main action to prevent a possible decline of the species is the preservation of quality of habitat through reinforcement of policies and the inclusion of the local population with public action to ensure sustainable urban growth. Creation and proper maintenance of additional conservation areas are also needed. The promotion of citizen science to include the local population and students in the preservation of these areas would be highly beneficial. Effective enforcement of conservation laws and policies are needed too.

The species is easily recognizable in the field, but further studies are needed, especially to increase knowledge about its geographical range. It is found on soil, probably as a saprotroph, but research is needed to understand other possible interactions, such as mycorrhizal, since white-sand soil areas have a high diversity of ectomycorrhizal species (Vasco-Palacios et al. 2018).

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Use and Trade

There is no use/trade of this species.

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Source and Citation

Komura, D., Costa-Rezende, D.H., Cabral, T. & Branco Rocha, F. 2024. Geastrum verrucoramulosum. The IUCN Red List of Threatened Species 2024: e.T265909362A265910298. .Accessed on 30 October 2024

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• Country occurrence