Lichen. Unidentified lichen growing on a rock. A lichen is a mutualistic organism comprising an alga and a fungus that live in a mutually- beneficial relationship. The alga produces carbohydrates for the fungus by photosynthesis,and the fungus protects the alga from harsh conditions. Lichens are highly sensitive to pollution: several are used as indicator species for sulphur dioxide levels in the atmosphere | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Fraser, Simon |
Taille de l’image : | 3992 px × 4961 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |