Book 25, Question 96 · Video
Why can lichens tell scientists about a city's air?
Lichens soak up water and air straight through their surfaces, with no roots or thick skin to filter them. That makes them sensitive to pollution. Some lichens disappear where the air has a lot of pollutants, while others can live in dirty air. By counting the kinds of lichens on tree trunks, scientists can judge how healthy the air is. More kinds usually means cleaner air.
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What Crafty Clover says in this video
Intro
Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why can lichens tell scientists about a city's air?
The Big Idea
Look closely at a tree trunk. You may see crusty gray-green patches. They are lichens, and they are air detectives!
No Filters
Step one: No Filters. Lichens soak up water and air straight through their surfaces, with no roots or thick skin to filter them. That makes them sensitive to pollution.
Clues
Step two: Clues. Some lichens disappear where the air has a lot of pollutants. Others can live in dirty air.
Counting
Step three: Counting. By counting the kinds of lichens on tree trunks, scientists can judge how healthy the air is. More kinds usually means cleaner air.
A Closer Look
Let's take a closer look! Some are leafy. Some are crusty. Some look bushy. All soak up air.
Quick Facts
Quick facts! Some lichens can live for hundreds of years. A lichen is a partnership between a fungus and a tiny algae. Lichens grow on rocks too. Look on tree trunks.
Think Like a Scientist
Now, think like a scientist! Look at tree trunks near you. Search for gray-green crusty lichens. Count how many kinds you can find. Draw each kind. Compare a busy street with a park.
Outro
Lichens tell scientists about air because they soak up air directly with no filter, so polluted air makes many kinds disappear. More kinds usually means cleaner air. Science is amazing! What will you discover next? Every question is a new adventure, so keep wondering and keep exploring with me! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!