Diversity and Distribution of Ectomycorrhizal Fungi from Amazonian Lowland White‐sand Forests in Brazil and French Guiana

Abstract

International audienceWhite-sand forests are thought to host many ectomycorrhizal fungi, as demonstrated by the numerous fruiting body collections made by Rolf Singer in the lower Rio Negro in the late 1970s. Despite recognition of the importance of ectomycorrhizal fungi in white-sand forests, there has not yet been a systematic examination of diversity and taxonomic composition across white-sand forests, or more widely across lowland Amazonian forests. In an effort to broaden our view of ectomycorrhizal fungal diversity and distribution on white-sand forests, we collected ectomycorrhizal fruiting bodies in 10 plots of white-sand forests in Brazil and French Guiana between 2012 and 2014. We collected 221 specimens and 62 morphospecies, from the 10 plots, confirming that all studied white-sand forests host ectomycorrhizal fungi. Additionally, we searched for taxa associated with white sands among specimens deposited in Brazilian herbaria. We report 1006 unique ectomycorrhizal specimen records in 18 Brazilian herbaria, of which 137 specimens and 64 species are reported from white-sand forests, mainly in the state of Amazonas, Brazil. Russulaceae and Amanitaceae were frequent in all habitats, and Cortinarius were more frequent on white sands. Our results highlight the high diversity and heterogeneity of ectomycorrhizal communities on white-sand forests, and the wide distribution of ectomycorrhizal fungi throughout Brazil, irrespective of soil type.Florestas em solos arenosos são consideradas como hospedeiras de muitos fungos ectomicorrízicos (EM), como demonstrado pelas numerosas coletas feitas por Rolf Singer na região do Rio Negro, Amazonas, no final dos anos 70. Apesar do reconhecimento da importância dos fungos ectomicorrízicos em florestas em solos arenosos, não houve nenhum estudo sistemático da diversidade e da composição taxonômica nas florestas em solos arenosos ou mesmo mais amplamente nas terras baixas da Floresta Amazônica. Para ter uma visão global da diversidade e da distribuição de fungos EM em florestas em solos arenosos, foram coletados basidiomas desses fungos em 10 parcelas de florestas em solos arenosos no Brasil e na Guiana Francesa entre 2012 e 2014. Além disso, uma busca foi feita por espécimes depositados em herbários brasileiros que tinham a informação de serem coletas feitas em solo arenoso. Nas 10 parcelas amostradas foram coletados 221 espécimes e 62 morfoespécies, o que confirma que todas as florestas em solos arenosos hospedam fungos EM. Recuperamos 1006 espécimes registrados em 18 herbários brasileiros, dos quais 137 espécimes e 52 espécies são registros de florestas em solos arenosos principalmente no estado do Amazonas, Brasil. Russulaceae e Amanitaceae foram frequentes em todos os habitats e Cortinarius foi o táxon mais frequente em solo arenoso. Os resultados apresentados enfatizam a alta diversidade e heterogeneidade das comunidades de EM em florestas em solos arenosos, assim como a ampla distribuição de fungos em todo o Brasil, não exclusivamente em florestas em solos arenosos

The (re)discovery of ectomycorrhizal symbioses in Neotropical ecosystems sketched in Florianópolis

“…Today, however, the known distribution of EMF remains patchy and biased towards accessible sites (see maps in Roy et al . () and Sulzbacher et al . ()).…”

“…() and Vasco‐Palacios () for Colombia): they expanded the range of soil conditions relevant for looking for EM symbioses. Despite an explosion of checklists and new species descriptions, species accumulation curves remain barely saturated (Roy et al ., ). Today, however, the known distribution of EMF remains patchy and biased towards accessible sites (see maps in Roy et al .…”

“…The presentations made it more and more obvious that EMF occur in many habitats scattered in Neotropical lowlands (see Roy et al . () for a review on Brazil; Sulzbacher et al . () for a review on neotropical hypogeous fungi; Wartchow et al .…”

“…()). Moreover, one‐third of EMF specimens in Brazilian herbaria belong to introduced species recorded from plantations (Roy et al ., ), such as the widespread Rhizopogon verii , which is associated with pines (Sulzbacher et al ., ). Unfortunately, comparisons between inventories are still limited because molecular data are often missing.…”

Discovery or Extinction of New Scleroderma Species in Amazonia?

“…After decades of collecting in rainforests, these three species have not been described before, and they could be endemic to their respective habitats. In a recent study of diversity and distribution of ectomycorrhizal fungi in white-sand forests in Amazonia (along the Cuieiras river) and French Guiana [70], only S . minutisporum [17] is mentioned.…”