First growth on Mount Etna
As shown in the pictures, lichens are starting to re-grow on bare volcanic rock. Lichen being a pioneer species which are the first to colonize previously disrupted or damaged ecosystems. Some lichens grow on rock without soil, so may be among the first life forms and break down the rock into soil suitable for other plants.
Just before writing this publication Mount Etna erupted, mainly effusive, in April 2017. Etna is still a very active volcano, but lichen can live, grow and re-seed even on a barren lava field. They are able to thrive in some of the most uninviting places on our planet and can tolerate huge swings in temperature and moisture conditions. If conditions are too stressful, though, they will go into a dormant state.
Lichens are a symbiosis between algae and fungi. The algae can photosynthesize and provide nutrients for the fungi. In turn, the fungi provides shelter so that the algae can survive in harsh conditions in which algae would not otherwise thrive.
Lichens can also accumulate trace elements present in volcanic emissions. Studies at Mount Etna show that in downwind areas heavily impacted by volcanic plumes, lichens contain a higher concentration of volcanic pollutants. These include fluoride, bromide, and metals, such as copper, lead, zinc, gold, mercury, and antimony.
The vegetation on Mount Etna changes as you rise, with pine trees, vineyards and chestnut groves giving way to broom and lichen. Etna is the home of many endemic plants and it is the best place for botanizing in Sicily. The right period to observe the Etna flora in blossom is from end of May to middle of July.
Mount Etna, lichen on volcanic rock at about 1600 m of altitude.
With thanks to Sebastiano Mirici, Mount Etna tour guide.