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11 Superb Facts About Mosses and Lichens

Have you ever been hiking and notice mosses and lichens on trees? In some places, they are growing everywhere and on everything that is solid like rocks.

Does seeing a lot of lichen on trees make you wonder if the trees are diseased or sick? When was the last time you recall seeing lichen or moss?

Have you ever come back to a place years later where lichen used to grow but you don’t see it now? Did you ever wonder why the lichen disappeared?

Maybe you haven’t thought about moss or lichens at all. But you should.


Mosses and lichens are organisms that can tell you a lot about the health of your environment. Depending on the lichens that are growing or not in an area tells a lot about the air quality of that area.

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Closeup photo of Foliose lichen on my Pink Dogwood Tree.

When I first moved to my current property, I became concerned about the number of lichens I saw growing on so many trees. It’s everywhere. It grows on so many different hard surfaces like my siding, parts of the patio, rocks and on trees. I also noticed large patches under the shaded areas of our lawn covered in just moss.

I became curious why I saw so much lichen and moss on this property and not on my last property which was 1 1/2acres. Both properties were only a 40 minute drive.

It inspired me to do some research on what lichens and moss are and what does it mean when they are growing abundantly or not.

As I learned more and more about lichens, I realized how fortunate I was to see so much of it.

Mosses rely on moisture to reproduce through spores.

What are mosses?

Mosses are small plants that have stems and leaves but don’t have veins, flowers or true roots. Their root system is called rhizoids which are small hairs that anchor them to hard surfaces.

You will find mosses in wet, dark and cool places in the forest. You can find mosses in gardens, rain forests, wetlands, caves and even on city pavement. They drink rain water and eat a simple diet of dust particles. Mosses prefer wet areas but can survive short periods of being dry.

What are lichens?

Lichens are a slow growing organisms that grow on living and non-living surfaces like rocks, trees and even siding. Lichens can be different colors, textures and shapes. There are almost 20,000 known types of lichens in the world and 3,600 living in North America.

Initially, lichens were thought to be plants. People still think lichens are plants. They don’t have leaves, roots or stems and they don’t need soil to grow. Scientific textbooks emphasized that lichen was a symbiotic relationship between algae and a fungus. But only recently, they discovered a third component called Cyanobacteria.

The fungus part of the lichen gives the structure that you see. The algae and Cyanobacteria provide food for the lichen through photosynthesis. Cyanobacteria does one more important thing. It releases Nitrogen that feeds the lichen and other plants.

Lichens collect rainwater but are unable to store it during long periods of drought.

You often see lichen on trees. This Dogwood tree is covered by all three types of lichens.

What are differences between mosses and lichens?

The main difference is that mosses are plants and lichen are algae/fungi.

Mosses require a lot of water to live and lichen can get by on very little water.

Mosses take in pollutants in the form of dust particles and release oxygen back into the air. They are like natures air cleaners.

Lichens aren’t able to do that. They absorb pollutants in the air too but they can’t release it or convert it. Lichens are important too because their health is an indicator of air quality.

Now that we know what mosses and lichens are, let’s explore some more interesting facts about how they contribute to nature.

1. Mosses contribute by preventing erosion.

Mosses can also serve as a really important tool in retaining moisture on lawns and controlling erosion. There are parts of our property that are covered by large patches of moss and I don’t see any evidence of erosion.

Another great benefit is we don’t have to mow over it. That part of our field is very low maintenance. For those who still use chemicals to control weeds, there wouldn’t be a need to use it. Plus, it’s soft to walk on and it attracts worms.

2. Lichen slowly creates soil

The lichen that grows on rocks or other hard surfaces slowly breaks them into soil. This is a very long process. As the lichen grows larger, it wedges the rock apart and creates an acid that further breaks apart the rocks releasing minerals into the soil.

3. Birds use lichen for their nests

When birds are busy building their nests in the spring, they will pull lichen on trees. Lichen provides structure to the nest. The grey color also makes a great camouflage to keep baby birds hidden from predators.

Find out more natural ways to attract more birds to your garden, click here.

4. Mosses and lichens are a food source for some animals

Lichens are a food source for deer, caribou, musk ox, brown lemmings, squirrels, snails and some insects. They also provide shelter for small insects like pill bugs that are important in supporting biodiversity in your garden.

Moss is a rough fiber that most animals would find it hard to digest. However, Lowland pikas do eat moss.

Are mosses and lichens safe for humans to eat?

Reindeer moss was one that indigenous people did eat but it isn’t recommended. Besides, there’s no nutritional value to it.

Native Americans ate a type of horsehair lichen that was brown similar to us eating a protein bar for convenience. They knew a yellow similar variety was toxic. Lichen’s are NOT recommended for humans to eat. They are very acidic and cause some serious belly pain. It doesn’t taste good either. Lichens are so important to biodiversity and environmental health; our goal should be to preserve them.

Both moss and lichen grow on trees. Mosses are being found to be good indicators of Cadmium air pollution according to this study.

Are lichens on trees bad?

Lichens grow on trees to get high enough to reach for food in the air and catch rain water.

When you see different types of lichen cover branches and trunks, it makes you wonder if this is harmful to trees. Many times, the trees that are covered in lichen seem sickly (like not producing normal leaves) and may die in a few years.

If you look closely, the lichen is only attached to the outside bark without making any holes or penetrating like a parasite would. It’s not harming it but lichen has a tendency to grow on trees that are already declining in health not adding to it.

The picture below that shows 3 different types of lichen on my Dogwood tree. Yes, I have seen this tree struggle in the last few years since I moved in. One year, it didn’t even bloom.

You can see all three varieties of lichen growing closely together on a Dogwood tree

Now you can see this same tree made a comeback in health this year and the lichen is still growing on it. Resist the compulsion to remove lichen from trees because you’d be doing more harm than good.

If you look closely, you can see lichen is still growing on this tree that has been struggling for a few years. In spring of 2023, this tree bloomed beautifully.

6. Lichens tell you a lot about your air quality

Scientists have done extensive studies and are able to determine the type of air quality based on the species growing in an area. Lichens are nature’s air quality monitors due to how sensitive they are to air pollution.

Because they absorb their nutrients from the air, pollution affects really quickly. An easy rule of thumb is the smaller the size and less variety of lichens growing in an area, the more polluted the environment is. Some varieties of lichen like Usnea lichens are extremely sensitive to Sulphur Dioxide pollution from burning coal. People with asthma can be very sensitive to this type of pollution.

7. Mosses can improve your air quality

When I started researching for this blog post, I had no idea that mosses help combat air pollution. Mosses soak up water even from the air and dust particles. They don’t need fancy sensors to monitor the air. They simply absorb the harmful particles.

The European Union is using different species of moss to address air pollution in their cities. Click here to read about this initiative in more detail.

What are other ways I can improve my air quality?

The good news is that as air quality improves lichens do grow back.

  • Write to your representatives repeatedly, provide them with scientific data about mosses and lichens being indicators of good air quality and about costly health problems form poor air quality. Different lichen types can tell you how good or poor the air quality is.
  • Plant lots of trees to improve the air quality.
  • Educate others about how air pollution affects health and lichens.
  • Lichens take a long time to grow, so if you have materials with lichen on them…try to repurpose them in some way so they can spread.
  • Don’t remove old trees because lichens prefer them. If you must cut them down, leave some logs at then end of your property for lichen to attach to.
  • Click here for more practical ideas to reduce air pollution.

8. Moss can be used as roofing material in a survival shelter

If you ever in a situation that you are stranded or lost in the woods, you can build a lean to for temporary shelter. The roof of the lean to can be reinforced with moss to absorb water. This will help keep you dry during the rain. Click here to watch a video how to make one.

9. How can moss be used as a bandage?

Moss was used as bandages during major wars. It was collected, sterilized and dried then stored in muslin bags for later use. As moss can absorb large amounts of water, it can also absorb blood. In fact, Sphagnum moss was used during World War I. Moss was a renewable resource that quickly grew back. For more information about how moss was used as a bandage, click here.

10. Dried moss and lichen can be used as kindling

Mosses and lichen are a critical part of our ecosystem so unless you are in survival mode to build a fire, you can use them in a pinch. For the vast majority of non-emergency situations, there are better kindling to start a campfire like dried pine needles, lint and dried grasses.

11. Indigenous people had many practical daily uses for moss

Moss was used as a sponge to wash dishes. Spanish moss used to be collected and sent abroad to as stuffing for chairs and mattresses according to this article from 1876.


Mosses are plants and lichen are more of an organism that is made up of a fungus and algae. Both get their nutrients and water from the air. Lichens can tell you a lot about your environment while mosses can improve the air quality of your environment. Mosses help prevent erosion while lichen break down rocks adding minerals to soil. Both are a food source for animals but it’s not recommended for people to consume. Birds use lichen to create structure for their nests.

In survival situations, moss can be used as a roofing material in a temporary shelter to keep you dry and be used as an absorbent bandage. Dried moss and lichen can be used as kindling for a fire. Indigenous people had many uses for moss like using it as a sponge to wash dishes.

Lichen takes a long time to grow so preserving it and encouraging it to grow can help improve our lives. Leaving old trees with lichen and repurposing wood outside can be a way to encourage them to spread. Educating ourselves and future generations how mosses and lichen play a key role in creating a health environment for all of us.