A forest of tree ferns. [Image: ttps://www.laterredufutur.com/accueil/la-plus-vieille-foret-du-monde-a-ete-decouverte-dans-letat-de-new-york/foret-380millions-dannees/]We are not alone in Nowhere Wood, about 300 million years ago. We are deep in a forest of tree ferns, towering above us, fifteen metres high. The damp air has a sweet and woody fragrance, heavy with spores, heavy with promise.
Carboniferous trees [Image: https://forces.si.edu/atmosphere/02_02_06.html]
The plants are silently photosynthesising, growing ever taller and adding oxygen to the air. Year after year, generation after generation.
Stages in the formation of coal. [Image: https://www.manalifelab.com/the-science]The wood in the tree stems is a new invention of evolution: no other plants have wood and fungi have yet to discover a way to eat it. This means that when the trees die and fall into the swampy wet soil, they do not decay, but stayed for thousands of years, gradually becoming compressed together to form deposits of coal.
The formation of most of our coal brought Earth close to global glaciation. [Image: George Feulner, https://www.pnas.org/doi/10.1073/pnas.1712062114]
The tree ferns took carbon dioxide from the air and locked it away as wood and coal. They took so much and the amount of carbon dioxide in the air fell so much, that the climate cooled, lead to the destruction of the tropical forests.
Today, humans have found the coal and burned it, putting the hidden carbon dioxide back into the air, re-warming the planet. No we face a global warming, not a global cooling. Perhaps, one day, Nowhere Wood will be destroyed for a second time.
Think about how interconnected the rocks, the trees, the atmosphere and the climate are. How does a change to one thing affect everything else?
Ferns are the first group of plants to develop proper roots. Think about why it would be an advantage for the early tree ferns to grow into sandstone.
Back then, the tree ferns grew through sandstone much as the smaller ferns in Nowhere Wood do today. Read more about this in another story: Climbing the walls.
