Why do some trees grow taller than others?
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From the brains behind Brains On, this is the Moment of Um. Moment of Um comes to you from APM Studios. I'm Shayla Farzan. Have you ever experienced awe? You know, that feeling when something stops you dead in your tracks and you suddenly realize just how amazing the world is?

There are all different things that can make you feel awe, like seeing beautiful art, hearing a song that moves you, or spending time with people you love.

I usually feel awe when I'm in nature. Like one time, I was hiking in California, and I turned a corner, and boom, there was the biggest tree I had ever seen. It was a redwood with thick, reddish bark and soft, needly branches. This tree was hundreds and hundreds of years old, which means it was probably a little sapling back when George Washington was alive. Wild, right? Yeah.

And it wasn't just old. It was huge, at least 300 feet tall. That's taller than the Statue of Liberty. Not all trees are hundreds of feet tall. And it kind of makes you wonder, why are some trees so big and others so small? Badger sent in a question about this, too.

I'm from Houston, Texas. And my question is, why do some trees grow taller than others? One of the main reasons certain trees grow taller than others is that they're different species. My name is Jake Misbauer. I'm an arboriculture scientist at the Martin Arboretum in Lyle, Illinois. I study how we can help people take care of trees that are growing in your backyard or in parks or in the city.

I've always loved trees ever since I was a little kid. Before I became a scientist, I was a practicing arborist. So what that means is I climb trees for a living. I had a harness that I wore and had ropes that were attached to that harness and climbed up in trees to cut off dead branches or sick branches and to help make the tree grow better.

Some of the trees that I climbed as an arborist were over 100 feet tall, which is as big as a 10-story building or about the size of a blue whale. So why do some trees grow taller than others? So there can be trees that range in sizes from really, really small to really, really big. And what species of tree it is plays a big role in that.

Your house cat and a lion are both types of cats, but the house cat is going to be much smaller than a lion. And trees are the same way.

But where they're growing also matters. Redwood trees growing in coastal California can get that big because the weather is great for growing conditions. Water from the root system up to the top of the tree is one of the reasons why trees can only get to be so big. So if redwood trees are growing someplace else where the growing conditions aren't as good, they're not going to get to be as tall.

Redwood trees are the largest trees in the world and they can get to be over 350 feet tall. There are eucalyptus trees in Australia that can get to be over 300 feet tall as well. The dwarf birch trees growing in the Arctic Circle have a very short period of time that they can grow and the conditions are really harsh so they just can't get very tall. Um, uh,

Trees come in all different sizes because they're different species, which is a fancy way of saying they're different kinds of trees. You can have huge redwood trees like what I saw in California or sugar maple trees or paper birch trees. These are all different species and they grow to different heights, but they also grow in different environments around the world. And that can affect how big they get, too.

Trees living in a mild environment with lots of water and good nutrients in the soil might get bigger than trees growing in really harsh conditions like the Arctic. You know what? All this tree talk makes me want to go out and plant my own redwood tree.

I bet in a really long time, when my great-great-great-great-great-great-great-great-great-great-great-great-grandkids are all grown up, that redwood tree will be huge.

If you like this episode, take a second to subscribe to Moment of Um wherever you listen to podcasts. And if you can't get enough of our leafy friends, check out the Brains On podcast where we have a whole episode all about trees. It's called How Do Trees Help Our Cities? Want to see our shows come to life? Head over to YouTube where we've got awesome animated Brains On episodes. Search Brains On Universe on YouTube and subscribe.

If you have a question, we'd love to help you answer it. Drop us a line by going to brainson.org slash contact. See you next time and the next day and every weekday. Until then, um... Whoa, now that's a really big tree.