TY - JOUR
T1 - Cyanobacteria are confined to dewless habitats within a dew desert
T2 - Implications for past and future climate change for lithic microorganisms
AU - Kidron, Giora J.
AU - Starinsky, Abraham
AU - Yaalon, Dan H.
N1 - Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/11/27
Y1 - 2014/11/27
N2 - Although covering almost all rock outcrops around the world, little is known regarding the factors that govern the spatial distribution of lithic cyanobacteria and lichens. This is also the case in the Negev Desert, where cyanobacteria predominate on the rock outcrops of the south-facing slopes and lichens on the rock outcrops of the north-facing slopes. Hypothesizing that abiotic conditions determine their distribution, radiation, temperature, rain, dew and fog were monitored over a two-year period (2008-2010) at cyanobacteria- and lichen-dwelling habitats within a first-order drainage basin in the Negev Highlands. While non-significant differences characterized the rain amounts, substantial differences in substrate temperatures were recorded which resulted in turn in fundamental differences in the non-rainfall water regime. While dew condensed at the rock outcrops of the lichen habitat, no condensation took place at the cyanobacteria habitat. Contrary to the common belief, cyanobacteria were found to inhabit dewless habitats. As a result, cyanobacteria solely rely on rain precipitation for growth and can therefore serve as bioindicators for dewless habitats within the dewy Negev Desert. The findings may have important implications regarding Earth colonization, soil forming processes and geochemical processes following climate warming. They may explain lichen expansion and subsequent O2 increase during the mid Neoproterozoic providing indirect support for substantial photosynthetic activity and high weathering rates during this era.
AB - Although covering almost all rock outcrops around the world, little is known regarding the factors that govern the spatial distribution of lithic cyanobacteria and lichens. This is also the case in the Negev Desert, where cyanobacteria predominate on the rock outcrops of the south-facing slopes and lichens on the rock outcrops of the north-facing slopes. Hypothesizing that abiotic conditions determine their distribution, radiation, temperature, rain, dew and fog were monitored over a two-year period (2008-2010) at cyanobacteria- and lichen-dwelling habitats within a first-order drainage basin in the Negev Highlands. While non-significant differences characterized the rain amounts, substantial differences in substrate temperatures were recorded which resulted in turn in fundamental differences in the non-rainfall water regime. While dew condensed at the rock outcrops of the lichen habitat, no condensation took place at the cyanobacteria habitat. Contrary to the common belief, cyanobacteria were found to inhabit dewless habitats. As a result, cyanobacteria solely rely on rain precipitation for growth and can therefore serve as bioindicators for dewless habitats within the dewy Negev Desert. The findings may have important implications regarding Earth colonization, soil forming processes and geochemical processes following climate warming. They may explain lichen expansion and subsequent O2 increase during the mid Neoproterozoic providing indirect support for substantial photosynthetic activity and high weathering rates during this era.
KW - Colonization
KW - Cyanobacteria
KW - Dew
KW - Lichens
KW - Negev
KW - Neoproterozoic
UR - http://www.scopus.com/inward/record.url?scp=84918806239&partnerID=8YFLogxK
U2 - 10.1016/j.jhydrol.2014.11.010
DO - 10.1016/j.jhydrol.2014.11.010
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AN - SCOPUS:84918806239
SN - 0022-1694
VL - 519
SP - 3606
EP - 3614
JO - Journal of Hydrology
JF - Journal of Hydrology
IS - PD
ER -