MICROCLIMAE, WEATHERING AND LICHENS IN THE CENTRAL NAMIB DESERT: A 3 YEAR INVESTIGATION OF BIOGEOMORPHIC INTERACTIONS

The hyper-arid central Namib desert is characterised by extensive gravel plains and rocky outcrops, in many cases covered by unique lichen-dominated ecosystems. A three-year study of mciroclimates, weathering and rock surface ecology at four sites across a c. 100 km transect from the coast inland has revealed the complesity of relationships between rocky surface ecology, rock breakdown and landscape at a range of scales. Lichens contribute both to weathering and protection of the desert surface, and their distribution is influenced by both geomorphology and microclimate. In turn, microclimate is a major control of the nature and rate of rock breakdown. Records of rock surface temperatures, fog and rainfall from 1999-2002 show huge variability at a range of temporal scales, which influences both weathering and lichen growth.