Cladonia dunensis Gumboski, Beilke & Eliasaro, Mycotaxon 124: 334 (2013)
A unique Brazilian Cladonia species due to the combination of morphology (differs from the others in terms of the branching pattern and surface of podetia), chemistry (one of the few species that produces psoromic acid) and ecology (on sand soil, exclusive presence in the interdune region). Other species that occur in the same region are quite distinct morphically and chemically, even when presenting podetia mixed between them.

Cladonia dunensis has a very restricted occurrence, found in the interdune region in the municipality of Imbituba, coast of Santa Catarina, Southern Brazil. In the same locality and environment, there are two spots where the species was found, forming small patches (<2m²) mixed with other species of the genus, usually close to herbs. EOO = 12.0 km2 (measured = 0.436km² ), AOO = 4 - 12.0km² , 1 location (most serious threat is development). Other similar environments in southern Brazil have been studied in the last 12 years and the species has not been found. The region suffers from intense real estate speculation for subdivisions, as can be seen in the newspapers, in addition to occasional anthropogenic fire, and the sporadic presence of cattle. Additionally, the area is intensively visited by tourists, which may lead to the destruction of the species patches by trampling. The entire environment is at risk, and due to the endemic characteristic of the species, it is classified as Critically Endangered: CR: B1ab(i,ii,iii,iv,v); C2a(ii).

It occurs in the interdune region of the municipality of Imbituba, coast of Santa Catarina State, Southern Brazil. Two ‘expressive’ areas were found, but only in this location. Other interdune regions of the Southern Brazilian region were also investigated, but no other areas have been found to harbor the species.
Brazil. Santa Catarina State: Municipality of Imbituba, 28°17ʹ57ʺS 48°42ʹ14ʺW, sea level, on acid soil in depressions between dunes.
There are one unpublished ‘record’, but the points have ca. 2 km away between them. The total area of the environment is 2.06 km², but the distribution within it is more restricted.

Based on the low abundance of podetia found throughout the potential area of occurrence, the total population is estimated at no more than 200 mature individuals, with each individual patch growing up to 2m², thus representing up to 2 mature individuals per patch. It shows a trend of population decline due to the threats described in item 5. As these species are long-lived, slow growing, and long-term stable substrate associates, the estimated generation time is 13-35years (25 years).
Other similar environments were studied (e.g., Gumboski & Eliasaro 2012a,b) in Southern Brazil, however, the species was not found in other locations either north or south of the indicated locations.

According to Gumboski et al. (2013), Cladonia dunensis was recorded only for the municipality of Imbituba, coast of Santa Catarina. The species occurs in the interdune coastal region, on the sandy soil of acidic characteristic (humic acids), and with podetia commonly intermixed with other Cladonia species, forming sparse, inconspicuous, irregular mats, up to 2m². It occurs in an open environment, sometimes close to herbaceous plants.
It only occurs in the stabilized soil of the interdune region. No thalli were observed in areas closer to the sea or in the dunes. The same environment present in other neighboring municipalities was studied in the following years, however, the species was not found.

The environment where Cladonia dunensis occurs suffers from strong real estate speculation with the purpose of subdivision for the construction of houses. The region is very popular for tourism and housing. In the summer, the city’s population doubles (about 80 thousand people), and the region of beaches and dunes is strongly visited, which is widely reported in the news (e.g., Dalponte, 2020; IMBITUBA, 2021). This characteristic can generate a direct impact on individuals of Cladonia dunensis through the trampling by tourists. The use of motor vehicles is prohibited in the dunes and interdune region, however, it is not uncommon to see people circulating with motorcycles and quadricycles in the area. Gumboski et al. (2013) also reports that the area develops an herbaceous vegetation that is often used for cattle grazing and is periodically burned, as observed in November 2011. Sea-level rise is also projected to threaten this species.

Actions to preserve this species revolve around the preservation of its habitat. The habitat where the species is found is considered a Permanent Preservation Area by the Brazilian legislation, and the area is inserted in the Baleia Franca Environmental Preservation Area (APA da Baleia Franca). Although protected, this conservation area category (Sustainable use) is highly permissive, allowing for tourism and other “low-impact” commercial activities. The creation of a more restricted protected area (Integral protection), such as a biological reserve, ecological station or park may be necessary, and its boundaries enforced, to prevent the entrance by tourists and cattle, as well as to endure political pressure to convert the area into housing.

More research is needed to better understand the species distribution and coverage in the region of occurrence, as well as an extensive survey through the coastal areas with similar habitat in southern Brazil, in search for other potential areas of occurrence.

None.

Dalponte, M.E. 2020. Praia do Rosa terá restrição de público durante o verão. Available in https://www.nsctotal.com.br/noticias/praia-do-rosa-tera-restricao-de-publico-durante-o-verao. Accessed in October 18, 2021.
IMBITUBA, Município de. 2021. IMBITUBA, A CIDADE QUE MAIS CRESCE NO SUL DO ESTADO. Available in https://www.imbituba.sc.gov.br/municipio/index/codMapaItem/16431.  Accessed in October 18, 2021.
Gumboski, E. L. & Eliasaro, S. 2012a Espécies de Cladonia P. Browne (Cladoniaceae, Ascomycota) dos Supergrupos Cocciferae, Crustaceae e Perviae em restingas e costões rochosos dos estados do Paraná e de Santa Catarina, Brasil. Acta Botanica Brasílica (Impresso), v. 26, p. 619-631.
Gumboski, E. L. & Eliasaro, S. 2012b. Espécies de Cladonia P. Browne (Cladoniaceae, Ascomycota) do Supergrupo Cladonia em restingas e costões rochosos dos Estados do Paraná e de Santa Catarina, Brasil. Hoehnea (São Paulo), v. 39, p. 315-337.
Gumboski, E. L.; F. Beilke & S. Eliasaro. 2013. Cladonia dunensis sp. nov. from southern Brazil, with notes on the genus in beach dune environments. Mycotaxon 124: 333-340.