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Lesson 2 - Ecosystems: Producers, Consumers, Decomposers

During this second segment, students continue to learn what composes an ecosystem, now focusing mainly on the biotic elements: producers, consumers and decomposers.

Lesson 2 Video Transcript

Hey, boys and girls. Steven and Vince back there from the Sandia Mountain Natural History Center. Um we're here to do the next part of our lesson. If you remember last time, we made a T chart on this board.

We had two names for those categories. One was Abiotic, the other one was biotic. If you remember and you can always look back on your other T chart, abiotic things in an ecosystem are like a rock something that can never be alive which means that it can also never do something else.

Can never die. So, abiotic things, things that can never be alive which means they never die. The other side which was over here was biotic. Like pine needles. They are biotic or a branch. It is biotic even though this one's dead. So remember the biotic things in ecosystems are the things that are alive and are also possibly dead. So what we're going to do this time is make that bigger.

We're going to put it into four groups. One of the groups is be the same. So, I want you to look on your T chart if you have it available. Which one of those groups that you listed things for, biotic or abiotic, was the smaller? Which one didn't have very much stuff in it? For me, it's always the abiotic. So, we're going to start off by making a four-square chart and the first thing we're going to put in it is abiotic again but that's the only time we'll see a repeat. So, up here, right? Abiotic.

And again, that A in Abiotic means not. So, it just means not biotic. So, this is the not biotic stuff. Now, I'd like you to spell the word Saws, S A W S. It's just an acronym, a word that's spelled made with the first letters as some other words.

It helps us remember the abiotic stuff in an ecosystem. Now, We have to think of things that are abiotic, not alive, not dead that start with an S, an A, or a W. One of them we had on our T chart before. One of the other things on our T chart could fit in one of these groups. It's part of it. So, let's just go down the row starting with an S. What am I standing on? If you're indoors, you're not standing on it most likely. If you're outside, quite possibly you are. It's the ground. So, I'm not standing on a sidewalk here.

Sidewalk wouldn't count for this. What kind of stuff? Do I have some up here? No. No. If you can see, what is this? Probably saw it. This looks like dirt, right? There's another word that we can use for dirt. Sometimes we think about it when we're going to start a garden. Yeah, soil. So soil, when we're talking about it today as far as being abiotic, it's the dirt, the rocks like the sandstone that we wrote up there before. Clay comes from the soil and then of course sand, all that kind of stuff. Not the dead stuff in there just yet, but just the the dirts and the rocks. That A.

If you remember from the other lesson, I had you guys take a deep breath in. Remember what it was? Yeah, air. Air is not alive. There's life in the air. I'm in the air. Birds fly through the air but the air itself is not alive which means it can also never die. A W. We don't see any right now. I don't see any. Oh, I do see some floating by up there. Obviously, I'm talking about clouds. Think about what clouds are made of. Think about what's in the tres right now. Why are these trees living? Think about what their roots absorb in the soil.

When it flows, sometimes it wears away, it erodes the ground, yeah, water. Now, water doesn't just have to be liquid. When it snows, that's water. When it hails, that's water. If it's foggy, that's water too. So, we can call it precipitation. We can call water precipitation as well. We got that last S. Oh, we're just now being able to see a change on the board.

It's not all in the shadow. We have these light spots. Yes, sunlight. Sunlight is abiotic. The important thing though that we're going to talk about is the light. What is light? Light is energy. So, what I'd like you to do is draw a wavy arrow like this into the next box. There's going to be a few wavy arrows like that on this box. It will always mean the same thing and that's energy. It won't always be light energy but it will be energy because the only time it's light energy is right now from the sunlight.

Now, it's starting to shine, that sunlight, it's starting to shine on the trees around me. What's happening there? Why is that a big deal? Well, yeah, because trees can do something with that sunlight just like all plants. It can take it and change it into its food. It needs other things like carbon dioxide and water too but the only form of energy that we're dealing with right there is the light. So, this next box is going to be the things in an ecosystem that need that sunlight to make their food. Obviously, those are the trees, the plants. So, this box, we're not going to write plants. We're going to write a longer word. That word is producers.

Think about what it means to produce something. If a factory produces cars, what are they doing? They're, that's right, they're making cars. So, plants are producers because they are making their own food. They don't have to go out and get it. They make it with that sunlight.

When you are looking for things whether it was in your house or apartment or if you got to go to the park or your backyard or front yard wherever, you probably saw some things that we could write in this producer box. If you saw a plant, you saw a producer. Remember these pine needles that I held up? There's two different kinds. This long one. This one was from a a ponderosa pine. The shorter ones. Those are from a piñon pine.

Because we have, see if I can pull this branch down. Can you see that branch right there? That's part of a piñon pine. Piñon pines are right there. Let's go ahead and write down piñon pine in this box. They are a very important tree in this ecosystem. Oops, They're very important tree in this ecosystem because there are so many of them.

What do pine trees grow off of their branches besides the needles? Yeah, the pine cones. Here's a pine cone. They don't just make 'em like this for no reason. There's a specific reason. What goes inside these little spots? The seeds. So, the purpose of all pine cones is to make seeds. Do you think all those seeds grow? Some of them do. Some of them don't do anything. They just end up dying. Some of them might get what? Yeah, they might get eaten.

Alright, another plant, another producer. Um Let's see. Can you see any more producers behind me? Vince, can you zoom out a little bit? Do you see anything else? Well, one other one we wrote down yesterday, and it's another important one, was the other kind of tree. Has little berries on it a lot of times, the grayish-blue berries. It's called a juniper. Let's write that one down again because that was so important. Juniper trees. They don't grow pine cones on em. They grow the little berries and like we talked about inside the berries is a little, yeah, seed. So, same story as the piñon seeds.

Those berries, some of 'em grow new trees. Some of 'em just die. They don't do anything. Some of 'em get eaten and if those seeds get crunched up, yeah, no seed, no trees going to grow there. Okay. So, a couple times, I talked about things eating those seeds. What is eating those seeds or anything else in the ecosystem? Animals. Because animals eat, we're going to call them something else. Just like we use producers for plants, we're going to use this word: consumers.

To consume can mean to eat. Consumers in an ecosystem are the eaters. That's how they get their energy. So, we need to add something from the producers going down to the consumers. What do we need to add? That energy arrow. Wavy arrow down here. The producers, the plants, take this in light, change it into the food that they use, but then also consumers can use the food that the producers create and eat it to get their energy. Did you guys see any consumers or animals when you're out looking for stuff? Consumers don't just have to be like a furry animal or a scaly animal like a lizard or snake. They can be bugs. They can be spiders. They can have feathers. You can, if you have a fish tank, they can be fish. Anything that has a mouth and eats is a consumer.

So, around here, we see them sometimes. We see other animals sometimes. We see their evidence though a lot more. What kind of evidence could say a deer leave behind as it walks through the forest? Yeah, it leave its tracks and we saw some yesterday. It could leave, well, if it ate a few hours ago, what's it going to need to do later? Yeah, it's going to have the poop, right? So, we can find deer scat out here in the forest and if you know, deer scat or any animal scat just refers to their poop. It's a word that we use when we do science outdoors and we talk about animals.

Let's go ahead and write down deer. Now, again, I didn't see the deer, but I saw their evidence, their tracks, and their scat. That's why I can write it down. And what do deer eat? Yeah, they just eat plants, leaves, maybe grass, things like that. What do you call that kind of animal that just eats plants? Herbivore, that's right, so deer are herbivores. Now what is an animal that might like to hunt that deer and all it eats is meat? You're right, it's called a carnivore, but what kind of animal--I'm going to lead you into a certain direction--you wouldn't want to be here by yourself if you saw that animal face to face.

Animal's pretty long and then it has a long tail, really sharp teeth. Yeah, mountain lion. Let's write down mountain lion? Mtn for mountain, and then lion. Like we just discussed, mountain lions just eat meat. They are a carnivore. They don't have any choice and where's it's getting, where is it getting its energy? Straight from the deer meat. Now, remember the evidence that I talked about that I could use to say that we have deer here? Their tracks and their scat. We do get evidence of mountain lions too.

Couple times we found some dead deer that the mountain lions have killed. Couple times we've gotten their tracks. Few times their scat. We have herbivores, carnivores. What's the other -ivore? Om...omnivore. What is a really big animal that's an omnivore that lives in the mountains? Yeah, bears. Every once in a while, we might see a bear. We might get a picture of a bear on our wildlife cameras out in the forest. And we find their scat a lot. Sometimes their footprints, but really their scat. You know, bears eat whatever they can find basically.

So, they are an omnivore. We need something to happen here. We had to have an empty box. Deer, they leave, uh, after the mountain lions hunt them, they don't eat everything so that we're going to have a carcass sometimes. But it doesn't stay there forever and a carcass is a dead animal. The plants that die. Trees fall over. They don't stay there forever. What happens to these things? What happens to the dead animals, to dead plants? Yeah, they, they rot, right? But there's another word that we're going to use. We're going to use this word. It's kind of a long one. Dead things de-com-pose, and the things that do that to those dead things are decomposers.

Just like consumers consume, producers produce. What kind of decomposers are out there in the forest? They can't be an animal. They cannot have a mouth because only consumers do. I'll give you a clue. One kind starts with an F. Another kind starts with a B. The one that starts with an F. We can eat some of them. Yeah, fungi. Two kinds of fungi. One kind I just mentioned we can eat. You know what it is. That's right. Mushrooms. Mushrooms. The other kind we might find on an old sandwich that you left in your lunch box for a month. Yeah, mold. We see mold all the time. Mold on old food. Mold on old beans, old bread, that kind of thing. So what's happening to that stuff? It's getting decomposed. These guys, the ones that start with the B. We can't see 'em usually unless we have microscopes.

Yeah, bacteria. Generally, usually, the fungi decompose the dead plants. The bacteria decompose dead animal stuff. Why do they do it? Why do they decompose? Not to clean up the forest for sure. That's not their job. They need something. What are these arrows? Energy. That's right. Decomposers whether it's mushroom, mold, or whatever, they need energy. Energy from dead animals or consumers. Energy from dead producers, plants. It's getting kind of messy. So, decomposers get their energy from dead stuff. Plants and animals that have died.

Consumers, get their energy from two places, either straight from the producers or from other consumers by eating them. Producers, get their energy straight from something that's 96 million miles away, the sun. That's right. So, what is the starter of all of the energy for life on Earth? Yeah, the sun. So, all living things. They need energy. All living things can get their energy from different places. That is one way to organize the things that we can find in the ecosystem.

The abiotic stuff and the biotic stuff. Alright, boys and girls, what I'd like you to do with your chart at home, again, just like you did with the T chart, look around your house, your yard, park, with your adult's permission, and see if you can add more things to these producers to the producer section, to the consumer section, and possibly to the decomposer section. Alright, we'll see you next time.