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Distance Learning Young Naturalists Club

Lichens: Virtual Field Trip, Jan. 8

Our friend Emily found these “British Soldier” lichen on Christmas Eve. Photo: Emily Walter.

What is so tough that it can survive on bark, rocks, dirt, and even outer space? A little organism called lichen.

You might have seen it before: lichen is that flat, green or blue, flakey stuff on tree bark or rocks. Sometimes people think it’s moss, but it’s not. Actually, I wondered on my last walk, what exactly is this weird thing?

On this week’s virtual field trip, we’ll find out just what lichen is and what it does!

CHOOSE YOUR LICHEN ADVENTURE:

Attend the virtual field trip, Friday, January 8 at 10:30. We’ll find out what lichen is and how it can survive harsh places!

Learn what lichen is: Read and look at pictures of lichen.

Look for lichen outside: What kind can you find? Does it tell you anything about the ecosystem?

Virtual Field Trip, Jan. 8 at 10:30am

Some lichen is so small that it looks like little dots on rocks. Photo: National Park Service/Jesmira Bonoan.

Every Friday from 10:30 to 11-ish am, we hold a Zoom call live from the woods for anyone who wants to join. This week, we’ll look at what lichen is, how it survives crazy conditions, and how you can recognize it!

If you haven’t registered for our field trips before, register here to get the link in your email:

The same link works each Friday.

What is lichen?

If you’ve ever noticed something that…
… is grey, blue-ish, green or lime green;
… growing off a tree, a rock, cement or just on the ground;
…looks like flakes, dots, or dust;

…then you might have seen a lichen! Here are pictures of common lichens here in southeast Ohio:

A lot of people think lichen is moss. But moss is a completely different organism. Here’s a picture of moss. Can you tell the difference?

Moss is a plant, with roots, leaves and stems. But a lichen is not a plant at all!

Lichen is actually part algae and part fungus*. These two organisms join together and live like one! It’s a little like Frankenstein’s monster, except helpful instead of scary. When two organisms work together like this, it’s called symbiosis.

Lichen is made up of algae and fungus, living together like one organism.

What is the algae’s job in the lichen? The algae makes its own food from the sun (also known as photosynthesis). The algae shares this food with its partner fungus.

The fungus’ job is making the lichen’s structure. Like a house, it gives the algae a safe place to live.

Do you think lichens are producers, decomposers, or consumers in the food web? Why?

Lichens do not have stems, roots, or leaves to move water, air and food around. Instead, lichens use all the cells in their body to breathe, eat and drink. They breathe in EVERYTHING that surrounds them. This makes them very sensitive to the air around them, like Goldilocks. Certain lichens can only grow in very clean, very filtered air, while others can handle harsher conditions. 

Because they are so sensitive, scientists use lichens as bio-indicators–a living thing that shows how healthy their environment is. The number, health and kinds of lichen we find give us clues about how healthy the whole ecosystem is.

In North America, 3,600 species of lichen have been discovered so far! More are being discovered every day.

Using what you know about lichens so far, why do you think they are so important to an ecosystem? 

*It’s also part yeast, and maybe a few other things. We are still learning what is in lichen!

Masters of Survival

Lichens need a lot of water. They are typically found near water, or north in areas that get a lot of fog. When lichens are wet, they photosynthesize and grow. When dry, they stop doing everything: no making food, no growing. This helps them save as much water as possible. 

This dry lichen can spring back to life if it gets a bit of water. Photo: sirwiseowl

So when you spot a lichen outside, ask yourself: is it dry and brittle, or wet and spongy? The answer will tell you about how wet that place is. It might reflect recent weather. And it will tell you whether the lichen is active, or dormant! 

Because they can turn themselves on and off, lichens are known as one of the toughest, hardiest organisms found in nature. They can live in extreme conditions: everywhere from the freezing arctic tundra to the blazing hot desert. In the arctic, lichens are the main producer feeding animals, because it’s so difficult for plants to survive there. This is because they can dry out when there isn’t water, and wait for water to return. Astronauts even put a dry lichen in outer space for two weeks, and it returned just fine!

Lichen grows places that plants can’t. Once lichen is established, plants might grow on the spot it prepared. Photo: National Park Service

Because lichens don’t need roots to get nutrients, they can live on many more surfaces: you see them on rocks, concrete, dirt, and tree bark. In places that are very hard to grow–like rocks or places where volcanoes exploded–lichens might be the first organism to grow there. They prepare the ground before plants can grow. They have two parts that keep them attached to their surface. The first, rhizines, look like little twisty roots. The second, holdfasts, are often compared to an umbilical cord. They are just one thick structure that holds the entire lichen to its spot. 

Lichens have a weak spot: they need very clean air to be healthy. Since they breathe in EVERYTHING in the air around them, you might not find them in polluted areas, like cities or near factories or power plants. 

How do lichens help the ecosystem?

Many animals eat lichen. They can also use lichen as camouflage. Small birds, like the ruby-throated hummingbird, use them to build tiny nests that are hidden from predators. Gray tree frogs blend right in with them as well. The tree frogs will sit right on the lichen on the tree! 

Humans use some lichens for dyes, medicine, and as a preservative. We are even able to eat certain types! Do you have a pool at your house? The small strips you use to test the pH of your water, litmus strips, are lined with the color-changing chemicals found in lichens.

Some animals that use lichens in our neck of the woods: 

  • Lacewing insect larvae (to live in)
  • Northern Parula, ruby-throated hummingbird, and blue-gray gnatcatcher (for nests)
  • Nuthatches and brown creepers (for food) 
  • Gray tree frogs (for camouflage)
  • Flying squirrels (for food and nests)

Identifying lichen

There are three groups of lichen: Foliose, Fruticose, and Crustose. I can’t always identify what exact kind of lichen I’m looking at, but I can usually identify its group!

Foliose

A foliose lichen.

Foliose lichen have 2 sides, like leaves on a tree. There is a top and bottom. They can be flat, leafy, or full of ridges and bumps. 

Fruticose

Fruticose lichen have more fruit-like shapes, rather than being flat like a leaf. They can go straight up and down, look almost hair-like and shrubby, or look like “cups.” 

Crustose

A crustose lichen. Photo: National Park Service

Crustose are like their name: they look crusty, and are often on rocks. They are flat and often have bright colors. 

With this information, what do you think is the most common kind of lichen in Ohio?

Your turn: Look for lichens

Now that you are an expert in the functioning of a lichen, go outside to try and find some!

  1. Look on trees, rocks, and other flat surfaces.
  2. Once you’ve spotted your lichen, try to figure out which of the three categories it belongs in: fruticose, crustose, or foliose. s it bright and colorful and flat? Or does it have bumps and ridges? What was it growing on?
  3.  If you can’t find any–why do you think that is? If you find a bunch, what does that say about that environment?

After you’ve thought about these questions, share what you found in the comments! We’ll help you identify them!

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Distance Learning Uncategorized Young Naturalists Club

Exploring the Forest Floor: Virtual Field Trip

Have you ever been out in the woods, seen a decomposing log on the ground, and flipped it over to see what’s hiding underneath? Were you surprised at what you found? Grubs and worms and snails–and all the other squishy bugs and animals that help the forest floor do its thing. 

Join us on Zoom for a virtual field trip to explore the forest floor this Friday, November 13, 2020. Or read on for ideas for exploring the forest floor yourself!

Attend the virtual field trip, Friday, November 13, 2020. Turn over leaves and logs with us!

Read about the levels of decomposition. We’re calling in the FBI (fungus, bacteria and invertebrates).

Go on a forest floor scavenger hunt. We have some suggestions for what you can look for down on the ground.

Attend the Virtual Field Trip

Friday, October 23, 10:30am

Every Friday from 10:30 to 11:00am, we hold a Zoom call live from the woods. This week, our naturalists will turn over logs and dig under leaves. Let’s see what we can find when we get down low on the ground!

You’ll receive the link for the Zoom call in your email. The same link works each Friday.

~~We’ll post the recording of the field trip here the following Monday~~

Layers of the forest

As most of you know, forests are very complex ecosystems. They have many layers, all working together to keep things healthy and stable. The forest floor is one of the most important, and probably the most overlooked, of these layers. 

The forest floor is the link between the above-ground plants and animals, and the underground soil and nutrients that help the forest grow. When you look at it above ground, it mostly looks like clutter–leaves, logs, bark, branches–and not much life. But if you take a closer look, you’ll notice that this layer has an entire mini ecosystem of its own!

Invertebrates, fungi, algae, bacteria: these small organisms work together to decompose (break down) that layer of clutter and turn it into a beautiful, nutritious soil. Let’s learn more about what these organisms are.

Levels of Decomposition

Decomposition is essential to all life! It is the process of taking something that was once alive (like dead trees and animals) and turning it into fuel for future life.  

Invertebrates

Invertebrates are the first level of decomposition in the ecosystem of the forest floor. Invertebrates are insects and other small critters without backbones. These insects and their allies feast on the litter on the ground. For example:

  • Ants break down leaves and other plant parts for food. Ants dig tunnels, which helps bring oxygen into the soil. This makes room for other plants to grow. Ants also eat other, more destructive insects like termites or aphids. Termites and aphids can kill living plants before it is their time.
  • Snails and slugs eat a variety of plants and fungi. When they digest the plants and poop them out, they return nutrients from the plant to the soil, so other plants can use it.
  • Worms eat the freshly decomposed soil made by other invertebrates. They filter it through their bodies to make their own special fertilizer.  However, some earthworms are invasive, or from other parts of the world. They can decompose the litter on the forest floor too quickly!

Fungi

Mushrooms and other fungi are the next level of decomposition. In some places, algae is more common.

Most mushrooms are much bigger than the toadstool you see. That little aboveground mushroom is just a small growth on its large web of its underground, cobweb-like “roots.” These underground webs and strands are called mycelium.

A fungus’ mycelium can grow for miles. The mycelium will eat everything they can get into! Instead of digesting food inside of them, like we do in our bellies, they disintegrate the food all around them, then absorb it. Some of that disintegrated matter is left in the soil for other organisms. The process can even clean pollution out of the soil!

Mutualism
Some kinds of mycelium and trees help each other out. The strands of mycelium grow around the roots of trees, and help the trees get water and food. The tree gives the mycorrhizae a home where it can to grow and reproduce. This is called a mutualist relationship, which is a kind of symbiosis.

Can you think of other things in a forest that have this type of relationship?

Bacteria

The final level of decomposition goes to bacteria and other microscopic organisms. Bacteria are single-celled organisms (teeny tiny pieces of life). These bacteria feed on dead plants, animals, and even fungi.

Bacteria are super important to the cycling of nutrients in soil called carbon, nitrogen, and phosphorus. Carbon, nitrogen, and phosphorus are kind of like plant vitamins. Plants need them to live. So it is very important that they get returned from dead plants to living plants!

Your turn: How to explore the forest floor

You might want: a magnifying glass and a small plastic container to hold specimens

autumn blur boletus close up
Photo: Lum3n on Pexels.com

Now that you know the layers of decomposition within a forest floor, go outside and try to find some invertebrates, fungus or bacteria!

Start by flipping over rocks or logs.

  • What do you see?
  • Can you see any of the bugs (invertebrates) that help with the first layer of decomposition?
  • Can you find a silky substance that looks kind of like an underground spiderweb? (This is the mycelium).
  • What do you think these do, and how do you think they work together?
  • For more ideas about what to look for, try the scavenger hunt below.
Forest Floor Scavenger Hunt

Look under logs and leaf litter for these signs of decomposition:

  • Worms
  • Worm trails
  • Grubs
  • Roly-poly (potato bug)
  • Slugs
  • Slug trails or slime
  • Snails
  • Mushrooms
  • Mycelium (mushroom “roots”), usually a silky substance found in the log itself. It might look like cobwebs or long skinny strands.
  • Ants
  • Salamanders

When you look for these things, try to use all your senses! What do they look, smell, sound, or feel like? Remember not to eat anything though, unless you have a trusted adult, or really want to eat a worm. 

Remember to put everything back where you found it after checking things out! This includes rolling logs back where you found them, and returning the leaves. While it may not seem like it, the forest floor is one of the most important and delicate aspects of the forest ecosystem. Remember, leave no trace! 

Take pictures or make some art based on what you find, and share in the comments below!