Airborne palynomorphs on Trindade Island, South Atlantic Ocean, Brazil

Abstract

The dispersion of palynomorphs in the atmosphere by wind plays an important role in the distribution of plant species and in gene exchanges among populations established on oceanic islands. In this study, we evaluated uninterrupted palynomorph rain for 19 months on Trindade Island (20°30 0 27 00 S-29°19 0 48 00 W) in the South Atlantic Ocean off the coast of Brazil. The objective of the study was to assess, using Tauber-type samplers, the atmospheric palynomorph population on the island and distinguish species of local origin from those transported long distances. The expedition was transported to the island by the Brazilian Navy. Samples were subjected to acetolysis followed by analysis in light microscopy. Palynological and accumulation rate diagrams are presented. A total palynomorphs of 11 pteridophytes, 9 angiosperms, 3 fungi, and remains of various animals are described and illustrated. After each description, a brief comment on the frequency and possible origin of the palynomorph is presented. The composition of palynomorph rain reflects the organisms extant on Trindade Island, together with material transported over long distances by atmospheric circulation.

DNA Metabarcoding Reveals Cryptic Geographically-influenced Microbial Diversity After Anthropogenic Impact in Original Forest Soils on the Isolated Trindade Island, South Atlantic

“…The fern Alsophila gigantea (=Cyathea gigantea) is an Asiatic species. Alves et al [21] reported spores of a different species of Cyathea in air samples obtained on the island. However, the assignment generated in the current study is likely to re ect a lack of completeness in the available database, and mostly likely refers to C. delgadii, the single and dominant tree fern on the island.…”

“…This vegetation recovery has likely relied on seeds, spores and propagules already present in the soil which, if viable, could develop under favorable conditions, or by new long-distance colonization events with propagules carried by agents such as wind, humans, and other organisms. Biological connections between Trindade and mainland South America have been demonstrated [20,21,7].…”