Lichens growing on the bark of a rowan tree (Sorbus aucuparia) near the coast. Three types of lichen are seen here. The white lichen is Parmelia laevigata,the green lichen is Lobaria virens and the grey/brown lichen is Pannaria rubiginosa. These last two are good indicators of air quality,as they are intolerant even of small amounts of the pollutant sulphur dioxide. A lichen is a symbiotic organism comprising an alga and a fungus. The alga produces carbohydrates for the fungus by photosynthesis,and the fungus protects the alga from harsh conditions. Photographed near the Sound of Mull,Scotland | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Burgess, Dr. Jeremy |
Taille de l’image : | 4548 px × 3114 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |