The structure and diversity of freshwater diatom assemblages from Franz Josef Land Archipelago: a northern outpost for freshwater diatoms

Sergi Pla-Rabés; Paul B Hamilton; Enric Ballesteros; Maria Gavrilo; Alan M Friedlander; Enric Sala

doi:10.7717/peerj.1705

The structure and diversity of freshwater diatom assemblages from Franz Josef Land Archipelago: a northern outpost for freshwater diatoms

PeerJ. 2016 Feb 18:4:e1705. doi: 10.7717/peerj.1705. eCollection 2016.

Authors

Sergi Pla-Rabés¹, Paul B Hamilton², Enric Ballesteros³, Maria Gavrilo⁴, Alan M Friedlander⁵, Enric Sala⁶

Affiliations

¹ CREAF , Cerdanyola del Valles, Barcelona , Spain.
² Canadian Museum of Nature, Research and Collections , Ottawa, Ontario , Canada.
³ CEAB, CSIC , Blanes, Girona , Spain.
⁴ National Park Russian Arctic , Archangelsk , Russia.
⁵ Fisheries Ecology Research Laboratory, Department of Biology, University of Hawaii, Honolulu, Hawaii, USA; National Geographic Society, Washington, D.C., USA.
⁶ National Geographic Society , Washington, D.C. , USA.

Abstract

We examined diatom assemblages from 18 stream and pond samples in the Franz Josef Land Archipelago (FJL), the most northern land of Eurasia. More than 216 taxa were observed, revealing a rich circumpolar diatom flora, including many undescribed taxa. Widely distributed taxa were the most abundant by cell densities, while circumpolar taxa were the most species rich. Stream and pond habitats hosted different assemblages, and varied along a pH gradient. Diatoma tenuis was the most abundant and ubiquitous taxon. However, several circumpolar taxa such as Chamaepinnularia gandrupii, Cymbella botellus, Psammothidium sp. and Humidophila laevissima were also found in relatively high abundances. Aerophilic taxa were an important component of FJL diatom assemblages (Humidophila spp., Caloneis spp. and Pinnularia spp.), reflecting the large and extreme seasonal changes in Arctic conditions. We predict a decrease in the abundance of circumpolar taxa, an increase in local (α-) freshwater diatom diversity, but a decrease in regional diversity (circumpolar homogenization) as a result of current warming trends and to a lesser extent the increasing human footprint in the region.

Keywords: Arctic; Climate change; Diversity; Indicator value; Indval; Ponds; Streams; β-diversity.

Grants and funding

Funding for this work was provided by National Geographic, Blancpain, Davidoff Cool Water, the Russian Arctic National Park, the Russian Geographical Society, and the State Nature Reserve—Franz Josef Land. A supporting Canadian RAC (2015–2017) grant to PBH was used to complete taxonomic SEM and LM investigations. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.