title: Cyanobacterial Diversity in Biological Soil Crusts along a Precipitation Gradient, Northwest Negev Desert, Israel.
abstract: Cyanobacteria occur worldwide but play an important role in the formation and primary activity of biological soil crusts (BSCs) in arid and semi-arid ecosystems. The cyanobacterial diversity in BSCs of the northwest Negev desert of Israel was surveyed at three fixed sampling stations situated along a precipitation gradient in the years 2010 to 2012. The three stations also are characterized by marked differences in soil features such as soil carbon, nitrogen, or electrical conductivity. The cyanobacterial biodiversity was analyzed by sequencing inserts of clone libraries harboring partial 16S rRNA gene sequences obtained with cyanobacteria-specific primers. Filamentous, non-diazotrophic strains (subsection III), particularly Microcoleus-like, dominated the cyanobacterial community (30% proportion) in all years. Specific cyanobacterial groups showed increased (e.g., Chroococcidiopsis, Leptolyngbya, and Nostoc strains) or decreased (e.g., unicellular strains belonging to the subsection I and Scytonema strains) abundances with declining water availability at the most arid, southern station, whereas many cyanobacterial strains were frequently found in the soils of all three stations. The cyanobacterial diversity at the three sampling stations appears dependent on the available precipitation, whereas the differences in soil chemistry were of lower importance.
authors.affiliation: Abteilung Pflanzenphysiologie, Institut für Biowissenschaften, Universität Rostock, A.-Einstein-Str. 3, 18059, Rostock, Germany, martin.hagemann@uni-rostock.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Hagemann
authors.forename: Manja
authors.initials: M
authors.lastname: Henneberg
authors.forename: Vincent J M N L
authors.initials: VJ
authors.lastname: Felde
authors.forename: Sylvie L
authors.initials: SL
authors.lastname: Drahorad
authors.forename: Simon M
authors.initials: SM
authors.lastname: Berkowicz
authors.forename: Peter
authors.initials: P
authors.lastname: Felix-Henningsen
authors.forename: Aaron
authors.initials: A
authors.lastname: Kaplan
mesh_terms: D001483:Base Sequence; D044822:Biodiversity; D016000:Cluster Analysis; D000458:Cyanobacteria / Q000235:genetics* / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D003889:Desert Climate; D005697:Galactosides; D007211:Indoles; D007557:Israel; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D011891:Rain; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D017931:DNA Primers; D005697:Galactosides; D007211:Indoles; D012336:RNA, Ribosomal, 16S; D012987:Soil; C044888:5-bromo-4-chloro-3-indolyl beta-galactoside