Margen
We tend to call the Amazon the lungs of the planet, but the label doesn't quite fit. Much of the oxygen you breathe doesn't come from forests, but from the sea.
It's made by phytoplankton: tiny algae and microbes that float near the surface and photosynthesise just like a leaf, only on a colossal scale. They're reckoned to produce around half of the atmosphere's oxygen. Put bluntly: one in every two breaths of air is born in the ocean.
One of its champions, Prochlorococcus, is so small it wasn't discovered until 1986, and yet it's one of the most abundant photosynthetic living things on Earth.
So next time you take a deep breath gazing at the forest, remember that half the favour is being done by something you can't even see.