Resumen

NUNEZ RAVELO, Franklin  y  TOLEDO BRUZUAL, Valentina. Variation in composition of the microbiotic crust according to the exposure (sunshine - shaded), in soils of the southern sector of the Barrancos river, Quibor valley, Lara state. Revista de Investigación [online]. 2013, vol.37, n.78, pp.193-212. ISSN 1010-2914.

The purpose was to compare the composition of the micro-biotic crust morphological groups according to exposure to sunshine and shade conditions in a semiarid environment. This is plotted on the two longitudinal transects surface and a quadrat square (25 x 25 cm) is used every ten meters in order to register the composition of the cover and scab and the exposure condition. Discontinuous growth is evident: registering 67.2% coverage, in the Solana area, consists of lichen, and in shady area extending 100% of the soil surface, containing 42.6% of lichen, 38.6% mixed and 18% bryophyte. We conclude that exposure to radiation conditions have an impact on the composition of the micro-biotic crusts, which is associated with the mechanisms of adaptation of each species.

Palabras clave : microbiotic crusts; exposure; composition.

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