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Lesson 5 - Leaves

This fifth segment of the Sandia Mountain Natural History Center's virtual field trip focuses on leaves: their types, characteristics, and purpose.

Lesson 5 Video Transcript

Good morning boys and girls. Welcome back to the Sandia Mountain Natural History Center. My name is Vince and I've been behind the camera while Steven was teaching over the past few videos and I thought I'd give it a try.

If you notice, there are trees all around me. I'm surrounded by the trees and if you remember back to one of the first videos when Steven was talking about the different parts of an ecosystem. Do you remember what we called plants and trees? That's right. It did start with a P. Do you remember that word? That word was producers. Now, let's think about producers for a minute. Why do we use that term producers? And why might they be important to the ecosystem?

That's right. Producers are those parts of the ecosystem that make their own energy out of sunlight. Now, let's think about producers for a minute. What do they provide to the rest of the ecosystem? Let's think about that for a moment. Let's think about trees. Let's think about plants. What do they provide to everything else?

Yes, that's right. They provide food to everything else in the ecosystem. What else might they provide? Everybody take a big deep breath. Hmm, what did we just do? We we breathed in. What did we breathe in? We breathed in oxygen. Where did that oxygen come from? If you're thinking from the producers and the trees, you're absolutely correct. That oxygen is released by the producers and we breathe it in as consumers, and when we breathe out, what do we breathe out?

If you're thinking carbon dioxide, you would be right. So, there's a relationship going on between the producers and consumers, not just for food but also for the air we breathe. Now, let's think about some other things that producers might be good for. What am I sitting at right here? I'm sitting at a table. What's this table made of? It's made of wood and where did that wood come from? It came from trees.

So, the furniture we have in our homes, in our classrooms also come from producers. Now, if you don't have one already, make sure that you have a notebook and pencil with you because you'll be using the notebook and pencil throughout this activity. So, let's think of anything else that producers might be good for for human beings and if you just thought of a pencil, you would be right.

The pencil came from a tree as well because it's made of wood. The paper that we write on also came from trees, didn't it? So, there's all sorts of things in the ecosystem within the producers that are important for us. Now, in a moment, you're going to be seeing a bunch of pictures of different kinds of producers. I want you to look carefully at those producers as those pictures go by and think about what you notice and when we pay attention to something really closely, what are we really doing?

There's a scientific term for that. That's right, that term is making observations. So, make observations of these images of the producers and pay attention to what's similar and different between all the different producers you're going to see. [no sound during slideshow] Alright, so now you've had a chance to look at different images of producers. What did you notice about all of them? What were they? If you're thinking plants, all different kinds of plants, you would be right. And so now, we're going to talk a little bit about different kinds of plants that live here in the Sandia Mountains, and we're going to pay particular attention to some of the different parts that are on the plants.

Now, you are looking at some of the different plants, you may have seen something that looked like this or something that looked like this. What are these things boys and girls? If you're thinking leaves, that would be correct. These are leaves. Now, what is the purpose of leaves? What do they do on a plant? You'll notice these leaves are green whereas these leaves are brown. What happened to the brown leaves. That's right, they died. Some types of trees have leaves that start out as green but in the fall, what happens to them?

They change colors. Have you ever been down to the river in the Bosque? Those big tall cottonwood trees, their leaves turn what color? Yellow, that's right. After they turn yellow as it gets colder, they turn brown and they fall off the trees. But when they're green, what are they doing for the tree? That's right. They're absorbing the sun's energy and creating their own energy through a process. Does anybody know what that process is called? If you haven't learned that, that's okay, but it's what we call photosynthesis. Do you know what's happening in photosynthesis? In photosynthesis, the trees are able to convert the sun's energy into what we call sugar and that sugar is called glucose. If you remember when Steven was talking, you may have noticed that some trees have something else.

What do we call these? What about this right here? That's right, they're needles, and needles are on a different kind of tree, aren't they? We also have something that looks like this. These aren't needles or leaves, are they? And we call those scales and if you look real closely, you can see the scales overlapping one another and they feel like the back of a reptile or a fish. Now, why do some trees have leaves like this? And other trees and plants have needles or scales? Because they're adapting to the habitat and the climate that they that they exist in. Now, does anybody know what we call a tree that has either needles or scales? I'll give you a little hint.

These trees produce something where their seeds are. What do we call these? We call these cones and so we call trees with needles and scales coniferous trees. Now, these other kinds of trees that have leaves like this leaf or something like this. We call deciduous trees. So, we have two kinds of trees, deciduous and coniferous. Now, one of the things we're trying to figure out is why do some trees have cones like these and some trees have needles, some trees have scales, and some trees have leaves.

Why might that be? Well, we talked about it earlier. It's because they adapt to the environment in which they live. Adaptations are super important and let's think about different kinds of adaptations besides leaves, needles, and scales. What other kinds adaptations might plants have? If you're thinking about different color of leaves, you would be right. Different kinds of plants have different color leaves for a specific purpose. In some climates like the desert southwest are fire prone.

Do you know what I mean by fire prone? That's right. Areas that sometimes can have wildfires and so some trees have developed the ability to survive forest fires and we'll talk about that sometime in another video I'm sure. At this point, we're going to go ahead and stop because we'll see you in the lab in just a few moments where we're going to look specifically at more adaptations that trees and producers have.

We just finished learning outside in the field about different kinds of leaves and we're now here in the, in our science lab at the Center and just a quick reminder about some different kinds of leaves that we've been talking about. So, if you remember, these are needles, right? What kinds of trees have needles like this? Or needles like this? Or even scales like this? Do you remember the word for that? That's right, coniferous. Now, we also have trees that have real leaves like these. What kind of trees have leaves like these?

That's right. Deciduous leaves or deciduous trees. So, in a moment, we're going to head to one of our lab benches and we're going to be spending some time looking at deciduous leaves, looking at their traits, their characteristics, and trying to understand how trees have adapted to their given climate. You guys ready? Let's go. So, let's look at these leaves. What do you notice about these leaves? What do each of them have? That's right.

They each have some parts and if you look closely, some of the parts are, this part here, right in here and we call that the leaf blade. That's the main part of the leaf. What else do you notice? That's right, you notice something sticking out of each of the leaves. We might want to call them a stem but technically that part is called a petiole. And if you look closely down at the base of the petiole, each leaf has what we call a node.

That's where the leaf attaches to the rest of the tree. And yes, you're right. There is something else you notice. Inside the leaf blade itself, you might notice these things that look like veins in different parts of the leaves. Just like us, leaves have to get their nutrients to all parts of their tree and leaf, and the veins take care of that. Let's look more closely at some of these leaves. You'll notice that these leaves are all singular. They all have one leaf.

Whereas other type types of leaves come together in multiples. So you'll notice that these leaves have more than one. Okay? This one has five. This one has many more than five and this one has even more than that. So let's take look at these. There's a specific name for these. The ones that only have one leaf are called simple leaves and these are called compound leaves. Now, we're going to look at the edges of the leaves. Let's look at the edges of these leaves. You notice how they're very smooth.

So, some leaves have smooth edges. While other leaves like these right here, if you look really closely, you can see they're not completely smooth. Instead, we like to call them wavy. Waves can be small like these or they can be bigger like these. Uh another kind of leaf edge is what we call leaves with lobes and if you look carefully here they have lobes right here they're bigger than the waves so we call them lobes and these have sort of smaller lobes just like our earlobe and then the last kind of leaf edge we have are leaves that are jagged and if you look closely here they have jagged edges almost like teeth on the edge of the leaves.

As we look at these leaves we're going to look at shapes. If you look at each of these leaves they kind of look like they all have different shapes don't they? But these two right here are more circular and what I mean by circular is if you draw a circle around the leaf, they form that shape, right? Not perfectly but pretty close. Same thing here. You get a circle going all the way around. This one right here and this one, what are those look like to you? If you said triangle, you'd be right. So, if I draw a triangle on it.

On this one, you'll be able to see the shape of the triangle, won't you? This one though when it matures and gets older and grows more is going to look like something else. What do you think that might be? If you look carefully, you might see a heart shape. Just like that. And lastly, these three leaves, what are those look like to you?

They're called lance-like leaves but they might look like a sword or a knife, something like that. So, as you can see, leaves have different shapes, circular, triangle, heart shape, and lance. And as we look at these leaves, boys and girls, what do you notice? That's right, you might notice different colors. Of course, we have green leaves right here and we have some green leaves here but notice they start to fade into a darker color, kind of like purple and then these are also purple and as you look at this leaf right here, it's looking sort of a dark green or a darker purple and finally, you have this lighter color.

So, leaves will also have different colors. When you look carefully at leaves, you might also notice that some leaves are very soft. Now, you can't really see it but if you touch it, it's very soft whereas these are more waxy and shiny. So, boys and girls, we've just spent some time looking at different traits and characteristics of deciduous leaves, haven't we? You might wonder exactly what a trait is. Well, a trait is just something that that shows us how something looks or how something grows and now, we're going to move into an activity, a hands-on project that you'll all participate in.

I'm going to show you how to do it. There's really two main parts. The first will be collecting and preserving leaves. The second part will be making leaf rubbings or drawings and identifying different parts, different characteristics of those leaves. As you can see, I've collected some leaves here and before I can do anything else in this, I need to go ahead and preserve my leaves because one of the things you'll notice is this leaf right here, notice that it's gotten, notice that it's gotten dried up and crinkled and curved. We don't want that.

We want our leaves to stay flat. So, the thing we need to do to make 'em flat is we take our leaves and take a of paper. Any kind of paper folded in half and then we're going to put a leaf in there just like that, okay? And you might not have a brand new sheet of paper, that's okay, maybe you have an old notebook paper like this and so we'll go ahead and take our leaves and put them in there just like this and keep them nice and flat. There we go and then we take our two sheets of paper and we're going to put them into a notebook just like this and we'll close our notebook like that.

The last thing to do, if you have something heavy like a rock or a can of food, go ahead and put it on just like that, and maybe leave it overnight. That way your leaves stay flat and then you can go ahead and start your leaf rubbings. As you can see, there's some leaves here and I'm going to move all the leaves out of the way except for one of them and I'm going to take this sheet of paper and put it right on top. I'm going to grab a black crayon and make what we call a leaf rubbing. Take a look at that. Pretty neat huh?

Now, we're going to do some other leaf rubbings besides this one in different colors and also using pencils or colored pencils. So, let's take a look at those as well. Here's another leaf. There's another sheet of paper and this time we're using a different color for crayon. It seems to work best if you're able to find the leaf edge. There we go. There's the leaf edge and once you find the leaf edge, keep rubbing around until you've got the entire leaf on your paper. Doesn't that look nice? Let's try a colored pencil now in a different leaf.

Let's see how this works. And it really helps if you put your finger kind of towards the tip of the the thing you're using whether it's a crayon a pencil or a colored pencil and there you go you've got another leaf rubbing and one more with just a regular pencil because some of you that might be all you have at home which is completely fine. Again you find the edge of the leaf oh look at that coming out just beautifully. Now, once you've made the leaf rubbings, your job will be to go ahead and label the leaf with some of the characteristics and traits that we've been learning about.

So, let's go back to the orange leaf that we made a rubbing of. Do you all see that? What are some of the parts of this leaf? What are some of the characteristics and traits of this leaf that we notice in the leaf rubbing? Well, it's a little hard for me to write upside down. So, I'm going to talk you through this a little bit. First of all, we know that it's a deciduous leaf, right? It's not scales or needles. We also might notice that the entire leaf part right here is the leaf blade.

We might have this petiole which we kind of think is like a stem. We might also be able to see the veins. You also will notice the shape of the leaf. In this case, it's fairly circular. The edges, though, are lobes. Now once you've identified and labeled your leaf, I'll ask you to turn it over, and go ahead and take your preserved leaf, grab a piece of tape or some glue if you have it, and glue or tape it down to the back.

And then you'll do that for all of the leaves, just like this one. We're going to tape it and ultimately you're going to be making a leaf book, so you have more than one kind of leaf and you'll go through and label each one with some of the different characteristics and traits we've been learning about.