As you read this, I’m in Sicily on vacation near the place of my father’s upbringing; a small ancient town called Tortorici. I’ve only been here for five days, and already the hustle and bustle of my modern life is fading away. Things just move slower here. Besides the alternate pace of day to day life, the scenery is just enthralling. Last week I had the opportunity to hike around the largest volcano in Italy, Mount Etna, at just under 11,000 feet. This geologic feature is truly massive as you can explore different formations for hours on end without the scenery becoming predictable. A few days later, I ventured off via boat to two smaller, off-shore volcanic islands, Lipari and Vulcano. These were far different landscapes compared to the mother of volcanos I visited earlier this week. These dynamic landscapes inspired me to do some research, and I just so happened to find a paper published in 1998 that tied together my new experiences with Mount Etna, Lipari and Vulcano with my passion for fungi.
Grasso and his team set off to see if they could utilize lichens growing on these volcanic as bioindicators. They hypothesized that these algal-fungal complexes could possibly accumulate the different elements emitted from these geologic features. Using Neutronic Activation Analysis and Inductively Coupled Plasma-Mass Spectrometry, these researchers collected and examined lichens from these different volcanic areas.
Their hypothesis was in fact supported by their results, as lichens mirrored the elemental lithosphere composition of their nearby volcano. The elemental composition of the lichens growing around the smaller volcanic islands shared many of same elements, while the lichens growing near Etna had their own unique elemental signatures. Furthermore, lichens that grew near urban centers had more pollutants like lead expressed in their tissues.
I’m not a geologist in the slightest, so it’s great to remind myself of these earthly processes that are carried out over millions of years. I am always reminded of diversity of soils found on this planet, and how soil properties can shape ecosystem functioning from the bottom up. This paper took this concept to the next level, helping me realize that the lithosphere is not homogenous by any means. Volcanoes around the world spew the distinct elements of the lithosphere they are resting on. From the bottom up, these abiotic factors shape plant and fungal assemblages, laying down the first filter for biological interactions.