A dry stone wall in Borrowdale Cumbria UK. Dry stone walls are widely used in Northern Britain as a durable stock-proof boundary to pastures. The materials used vary with availability,and may include river cobbles,clearance stones from pastures,and quarry stone or slate. The pictures shows the west-facing side of a wall 50m above sea level,built from a mixture of cobbles and clearance stones The rock is of the Borrowdale Volcanic series. The surface of a dry stone wall is a harsh environment; here,it supports a variety of crustose lichens,the most obvious being the lime-green Rhizocarpon geographicum,or map lichen. Lichens are the result of a symbiotic relationship between a fungus and an alga; this partnership is able to wthstand conditions of drought and extremes of temperature that would be fatal to either constituent on its own | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Burgess, Dr. Jeremy |
Taille de l’image : | 5212 px × 3468 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |