Cyanobacterial populations in biological soil crusts of the northwest Negev Desert, Israel-effects of local conditions and disturbance.
Biological soil crusts (BSCs) fulfil numerous ecological functions in arid and semiarid areas. Cyanobacteria are important BSC organisms, which are responsible for carbon fixation, N2 fixation and binding of soil via extracellular polysaccharides. The cyanobacterial populations were characterised in different sampling plots established in three experimental stations along a rainfall gradient within NW Negev Desert, Israel. Cyanobacterial crust thickness and osmolyte accumulation therein decreased in plots with lower moisture. The cyanobacterial population structure also changed in different plots. We observed an increase of subsection III cyanobacteria such as Microcoleus spp. and Leptolyngbya spp. and a decreasing proportion of strains belonging to subsections I and IV in drier areas on the rainfall gradient. This population shift was also observed in the sampling plots, which were situated at various relief positions within the sand dune experimental sites. We also characterised the cyanobacterial populations within mechanically disturbed plots. After 4 years, they reached between 80% and 50% of the control populations in the northernmost and southern stations, respectively. Our results suggest that the cyanobacterial population is sensitive not only to macroscale factors but may also be subject to local climate variations and that 4 years was insufficient for complete recovery of the cyanobacterial population.
Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, D-18059 Rostock, Germany.
Martin
M
Hagemann
Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, D-18059 Rostock, Germany.
Manja
M
Henneberg
Institute for Soil Science and Soil Conservation, IFZ-Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 26, D-35392 Gießen, Germany.|Department of Soil Science, Faculty of Organic Agricultural Sciences, University of Kassel, Nordbahnhofstr. 1A, D-37213 Witzenhausen, Germany.
Vincent J M N L
VJMNL
Felde
Department of Plant and Environmental Sciences, Edmond J. Safra Campus - Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.|Arid Ecosystems Research Center, Edmond J. Safra Campus- Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
Simon M
SM
Berkowicz
Institute of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA.
Hagai
H
Raanan
Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, D-18059 Rostock, Germany.
Nadin
N
Pade
Institute for Soil Science and Soil Conservation, IFZ-Research Centre for BioSystems, Land Use and Nutrition, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 26, D-35392 Gießen, Germany.
Peter
P
Felix-Henningsen
Department of Plant and Environmental Sciences, Edmond J. Safra Campus - Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.|Arid Ecosystems Research Center, Edmond J. Safra Campus- Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
Aaron
A
Kaplan
D000077194:Chlorophyll A / Q000032:analysis; D000458:Cyanobacteria / Q000145:classification*; D003889:Desert Climate; D007557:Israel; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
D012987:Soil; D000077194:Chlorophyll A