Lichen Colonization on Cobbles in the Negev Desert Following 15 Years in the Field

Abstract

Rock slabs were placed from 1991 through 2006 at the bottom of a north- (NFS) and a south-facing (SFS) slope of a first order drainage basin in the Negev Desert Highlands, Israel (P = 95 mm) where natural cobbles have >95% cover of endolithic and epilithic lichens. Periodic measurements of rain, dew and chlorophyll content took place. Lichen cover and the regeneration time were aspect-dependent. Lichen cover was 98% and 61% at NFS and SFS, respectively, while the lichen's recovery time was respectively ∼45 and ∼80 years. The fast regeneration time may have important implications regarding weathering and soil formation.

Keywords:

• dew
• growth rate
• ichen cover
• Negev Desert

The study was supported by grant 1358/04 of the Israel Science Foundation (ISF). We would like to warmly thank Avraham Starinsky for his support, making the research available, Shimon Tal for technical assistance and Carol A. Kidron for the editing.