Vast armies of yellow, orange, green, blue, black, and any other color imaginable spread across the barren landscape. After an asteroid impact wiped out the majority of species on this planet, these colorful symbionts march forth to take advantage of the wide open world. Two unlikely organisms join forces to thrive in this new world. Fungi and algae (or sometimes cyanobacteria) join forces to make lichen. But they must out compete others of their kind for space and resources. One thing is certain, once the dust settles multiple forms of lichen will have found a way to colonize an area while other species struggle to reestablish themselves. Not only are these tiny organisms powerful armies, but they have a lot to teach us about ecosystems, climate change, and even space!
After a disturbance, such as wildfires or tsunamis, in an ecosystem lichens are some of the first organisms to repopulate an area. They reproduce and spread very quickly and can grow on virtually any surface. The fungus part of lichen is responsible for creating a stable home while the algae is responsible for providing food and energy through the process of photosynthesis. Together, they make the symbiotic relationship known as ‘lichen.’ But without each other, the algae would be secluded to aquatic environments to live while the fungi would work a lot harder to create food for itself. Recent research even suggests that this dynamic duo was one of the first organisms to thrive after the mass extinction event that killed off all the dinosaurs! Being some of the first creatures to inhabit an area, lichens break down various materials they come in contact with to create a nutrient-rich soil for plants to grow upon. Animals, in turn, will eat the plants and thus a stable ecosystem is born.
Not only are they important organisms for creating a habitable ecosystem, but humans are starting to find answers to a wide variety of questions thanks to the hard work of lichens. Lichens absorb water and other airborne molecules as part of their metabolism. Because of this, lichens can be great indicators of air pollution and climate change. By measuring the health of various lichens in an area, scientists are discovering how air pollution is effecting an ecosystem and the extent of various pollutants in that environment. Scientists have also discovered that Lichen can exist in the vacuum of space and on the barren surface of Mars! Why do we care about this? This could help us identify the types of life that may be discovered on other planets.
So far I hope you can see that when it comes to lichens there is way more than meets the eye. Here are three more parting facts about lichen.
- Lichen as a food source and protection: Many microscopic creatures call lichen home including tardigrades. Some insects use lichen as a camouflage covering by chewing off a piece of lichen covered tree bark and sticking on their backs. Most caribou and reindeer rely on lichen for the bulk of their food supply– reaching as high as two-thirds the food supply of caribou.
- Lichen beauty products: Lichen, and various molecules that lichen produces, are used in the production of perfume, toothpaste, sunscreen, and deodorant!
- Lichen wars: Lichens are known to attack each other when competing for space and resources. Depending on the type of lichen, you may see them attack each other with spores, use chemical warfare to inhibit other lichen growth, or pile up on top of other lichens to suffocate them.
**If you read this whole blog post, you are my hero! Thanks for reading. Please feel free to leave me a comment and feedback below. Also, let me know if there is any particular science topic you would like me to look at “through green tinted glasses” and I will write about it.**
*All photography in this blog post was taken by myself, Jay Merrill, and is the property of the blog owner.