caa a22 4500 605527555 CHVBK 20210128100809.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s10531-015-0907-7 doi (NATIONALLICENCE)springer-10.1007/s10531-015-0907-7 Microstructure and cyanobacterial composition of microbial mats from the High Arctic [Elektronische Daten] [Asunción de los Ríos, Carmen Ascaso, Jacek Wierzchos, Warwick Vincent, Antonio Quesada] Arctic lakes, ponds and streams contain benthic microbial mats that are dominated by cyanobacteria, and these communities often account for a large proportion of the total ecosystem biomass and productivity. The vertical structure and composition of mats from two different aquatic habitats in the Canadian High Arctic, Ward Hunt Lake and a polar desert stream were analyzed in detail by microscopy techniques. Two distinct layers were identified in each mat: a surface layer with a high density of cells and associated extracellular polymeric substances (EPS), and a less cohesive bottom layer with an accumulation of mineral particles. The matrix formed by the cyanobacterial filaments and EPS produced the complex microstructure of all three mats, and likely favoured different microenvironments where specialized microbial interactions and biomineralization processes could take place. Structural and compositional differences were found among the mats. The lake mat had a surface layer of Dichothrix, and contained abundant particles of calcium carbonate, while Tychonema-like and Tolypothrix-like appeared mainly in the stream mats, along with a higher diversity of Chroococcales. A black microbial mat from one of the stream sites had markedly lower diversity than the other mat types. The observed differences in cyanobacterial composition and physical structure may be related to habitat stability and the availability of liquid water. Springer Science+Business Media Dordrecht, 2015 Cyanobacteria nationallicence Habitat stability nationallicence Microbial ecology nationallicence Polar regions nationallicence Water availability nationallicence de los Ríos Asunción Museo Nacional de Ciencias Naturales, CSIC, Serrano 115 dpdo, 28006, Madrid, Madrid, Spain aut Ascaso Carmen Museo Nacional de Ciencias Naturales, CSIC, Serrano 115 dpdo, 28006, Madrid, Madrid, Spain aut Wierzchos Jacek Museo Nacional de Ciencias Naturales, CSIC, Serrano 115 dpdo, 28006, Madrid, Madrid, Spain aut Vincent Warwick Centre d'études nordiques (CEN) & Dépt de Biologie, Université Laval, G1V 0A6, Quebec City, QC, Canada aut Quesada Antonio Dpt. Biología, Universidad Autónoma de Madrid, 28049, Madrid, Spain aut Biodiversity and Conservation Springer Netherlands 24/4(2015-04-01), 841-863 0960-3115 24:4<841 2015 24 10531 https://doi.org/10.1007/s10531-015-0907-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10531-015-0907-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- de los Ríos Asunción Museo Nacional de Ciencias Naturales, CSIC, Serrano 115 dpdo, 28006, Madrid, Madrid, Spain aut NATIONALLICENCE 700 1- Ascaso Carmen Museo Nacional de Ciencias Naturales, CSIC, Serrano 115 dpdo, 28006, Madrid, Madrid, Spain aut NATIONALLICENCE 700 1- Wierzchos Jacek Museo Nacional de Ciencias Naturales, CSIC, Serrano 115 dpdo, 28006, Madrid, Madrid, Spain aut NATIONALLICENCE 700 1- Vincent Warwick Centre d'études nordiques (CEN) & Dépt de Biologie, Université Laval, G1V 0A6, Quebec City, QC, Canada aut NATIONALLICENCE 700 1- Quesada Antonio Dpt. Biología, Universidad Autónoma de Madrid, 28049, Madrid, Spain aut NATIONALLICENCE 773 0- Biodiversity and Conservation Springer Netherlands 24/4(2015-04-01), 841-863 0960-3115 24:4<841 2015 24 10531