Distribution of aerophilous diatom communities associated with terrestrial green macroalgae in the South Shetland Islands, Maritime Antarctica.

Juliana Ferreira Da Silva,Antônio Batista Pereira,Margéli Pereira De Albuquerque,Eduardo Pereira Da Silva,Filipe De Carvalho Victoria,Adriano Luis Schünemann,Maria Angélica Oliveira Linton,Rodrigo Paidano Alves,Raylane Ribeiro Da Anunciação,Jinzhuang Xue

doi:10.1371/journal.pone.0226691

Abstract

The establishment of diatom communities depends on environmental factors such as the type of substrate and geographic conditions that influence the dispersal processes of these organisms. The main goal of this study was to evaluate the similarity between diatom communities associated with the macroalgae Prasiola crispa (Lightfoot) Kützing in relation to spatial distance from six sampled sites located in the South Shetland Islands, Maritime Antarctica. The diatom flora associated with Prasiola crispa was represented by 23 species distributed in 15 genera. Pinnularia australoschoenfelderi Zidarova, Kopalová & Van de Vijver, Luticola austroatlantica Van de Vijver, Kopalová, S.A.Spaulding & Esposito, Luticola amoena Van der Vijver, Kopalová, Zidarova & Levkov, Pinnularia austroshetlandica (Carlson) Cleve-Euler and Psammothidium papilio (D.E. Kellogg et al.) Kopalová & Zidarova were the most abundant species in our samples, together they represented 68% of the total number of individuals collected. There was great similarity and abundance of the diatom communites among the sampled points, which resulted in the absence of a linear relationship pattern with distance between sampling points. We conclude that distance was not a factor of differentiation of Antarctic diatom communities associated with terrestrial green macroalgae. This suggests that Antarctic environments may have unique characteristics with homogeneous abiotic factors, at least in relation to this substrate.

Highlights

The diatom species diversity of the Antarctic is limited by extreme conditions, and studies have led to the conclusion that not all Antarctic islands share a similar flora, the overall diversity of this flora on the continent is limited compared to tropical and subtropical regions [1]
Many of the diatom taxa recently described are endemic to Antarctica and not cosmopolitan [2,3]
The main goal of this study was to evaluate the similarity between diatom communities associated with P. crispa spatially distributed in six sites located in the South Shetland Islands, Antarctica

Summary

Introduction

The diatom species diversity of the Antarctic is limited by extreme conditions, and studies have led to the conclusion that not all Antarctic islands share a similar flora, the overall diversity of this flora on the continent is limited compared to tropical and subtropical regions [1]. Regarding the study of diatom communities, in recent years, a more refined taxonomy has revealed a large number of new species in Antarctica [4,5,6,7,8,9,10,11,12,13,14,15,16]. Prasiola crispa (Lightfoot) Kutzing is a terrestrial species of Antarctica, which usually grows on moist soils that are fertilized by bird guano, being more abundant inside and around penguin colonies. These macroalgae tolerate repeated cycles of freezing and thawing during the year, as well as high levels of UV radiation during the summer [17]. At the micro-scale level, the substrate of periphytic communities may provide more than an inert surface, since its physical and chemical characteristics can influence the composition of the community and algal biomass [18,19,20]

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Results