Lesson video

Hi everyone.

I'm Miss Reid and welcome to our third lesson on biomes.

Let's have a look at our key question for today.

Our key question today is what affects a biome? Well, in this lesson we're going to be learning about the climatic factors and human activities that impact biomes and the ecosystems within them.

Now in this lesson, you'll need: an exercise book or a piece of paper, and a pencil, and your brain.

Please take a moment now to clear away any distractions, including turning off any notifications, or apps, or conversations that you've running in the background if you know how to.

Finally, if you can, try to find a quiet place where you won't be distracted during today's lesson.

Pause the video now so you can go and get the things that you need and try and find a quiet place to work.

Great.

Now you have everything you need.

Let's carry on.

So we are geographers.

Now, geographers, as you know, are types of scientists who study the earth.

This includes the land, the physical features, and the people who live within it.

And these are what we call the human features.

In today's lesson we're going to be looking at global biomes.

We're going to be thinking about climatic factors that affect the biome.

And we're also going to be thinking about human activity that's affect the biome.

So here is the map that we've been studying, showing us the location of the biomes across the world.

We have learned that there is huge diversity across continental biomes, due to their proximity, how close they are to the equator.

In this lesson, we're going to consider the climatic features and the human activities that impact biomes.

When we talk about climatic features, we're thinking about the climate.

So, the first climatic factor that we're going to be thinking about is temperature and precipitation.

So, temperature is the degree or intensity of heat present in the atmosphere.

And we usually measure the temperature with a thermometer in either degrees Celsius or degrees Fahrenheit.

Precipitation is often thought of as rain.

But precipitation is not just rain.

It's also snow, sleet, or hail that falls too, or condenses on the ground.

Let's recap on those things.

So the temperature is the degree or intensity of heat present in the atmosphere, measured with a thermometer in either degrees Celsius or degrees Fahrenheit.

And precipitation is rain, snow, sleet, or hail that falls to or condenses on the ground.

We're going to read some information about temperature and precipitation.

I'm going to read it along here and you can read along with me at home.

Temperature and precipitation of very important physical features that influence the characteristics and distribution, location, of biomes.

So when we think about temperature and precipitation, we think of them as very important because they determine where in the world a biome is going to be.

But they also determine the characters, the features of that particular biome.

Let's keep reading.

Differences in temperature or precipitation determine various aspects of the biomes, such as plants.

Biomes with low precipitation and extreme, very low or very high temperatures, have short growing seasons and poor soil.

Resultantly, fewer kinds of plants and animals are able to grow and live in these environments.

So, biomes with low precipitation and extreme growing, extreme temperatures have difficult growing conditions.

We talked about the fact that they have short growing seasons and poor soil.

Let's carry on reading An example of a biome with low precipitation and extreme temperatures are deserts and tundras.

You're now going to use the information that we've just read to answer a question.

The question is, what happens in a biome with low precipitation and extreme temperatures? Look out for those key words in the text on the left-hand side.

Pause the video and answer the question now.

Let's see how you did.

So I said, biomes with low precipitation and extreme temperatures, either hot or cold, have short growing seasons, and poor soil.

Pause the video now so you can tick or fix your answer.

Well done everyone.

Let's move on.

So the next factor that we're thinking about, called climatic factors, we're thinking about is elevation.

Now, elevation is the height of the land above sea level.

Let's recap that again.

You can say it with me.

Elevation is the height of the land above sea level.

Great work.

Also going to read some information about elevation.

I'm going to read it on here and you can read along with me at home.

Elevation has significant impact on biomes.

The change occurs because the atmosphere becomes thinner at higher elevations, which means that the temperature is lower.

So, we can think of this as higher elevation, thin air, low temperature.

I'm going to say thin air.

You're going to say, or air thinner, and you're going to say low temperature.

Air thinner.

Air thinner.

Air thinner.

Low temperature.

Well done for saying air thinner.

So as the elevation becomes higher, the air becomes thinner and the temperatures are lower.

Let's keep reading.

Elevation affect precipitation because when clouds fill with moisture, they rise and cool, which forces them to release rain or snow, precipitation.

You have now got a task to complete.

You need to complete the sentence.

At higher elevations, the atmosphere becomes, which means the temperature is.

Pause the video so you can complete that sentence.

Let's see how you did.

At higher elevations, the atmosphere becomes thinner, which means the temperature is lower.

Pause the video now so you can tick or fix your answer.

Excellent work everyone.

Let's move on.

So another climactic figure or feature is ocean currents.

Now, ocean currents are a physical factor that are in constant movement and affect the weather.

You can see from this diagram that the ocean currents are constantly moving.

Ocean currents can help to make climates less extreme.

That means that they can help to make them less cold or less hot.

For example, ocean currents transfer heat from the tropics to the polar regions and other parts of the world.

If we zoom in on this diagram, we can see that here the ocean currents are transferring warm surface flow or warm water, warm currents, up to the polar region and also to this part of Northern Europe.

They then take colder currents back down and the cycle begins again.

Now, the heat from ocean currents keeps much of Northern Europe significantly warmer than other places equally as far north.

So when you look on the map there are places such as Eastern Asia, which I'll show you here, which have cold currents passing by them.

That means that they're not as warm as parts of Northern Europe, which are on the same latitude.

Now, ocean currents are also important for more than just the climate.

They're also important for food chains and the reproduction of marine organisms and marine ecosystems. So, I'm going to present you with the same information that I just gave you, but this time it's going to be in written form.

We'll read it through together.

Ocean currents are a physical factor that are in constant movement and affect the weather.

Ocean currents can help to make the climates less extreme.

For example, ocean currents transfer heat from the tropics to the polar regions, influencing local and global climates.

The heat from ocean currents keep much of Northern Europe significantly warmer than other places equally as far north.

Ocean currents are also important for food chains and reproduction of marine organisms and marine ecosystems. You've now got a question based on this information.

The question says, why is Northern Europe significantly warmer than other places equally as far north? Pause the video and use the information on the left-hand side to answer that question.

Let's see how you did.

So, I wrote Northern Europe is significantly warmer than other places equally as far north because ocean currents transfer heat from the tropics to Northern Europe.

You can pause the video now while you tick or fix your answer.

Excellent work everyone.

Let's move on.

So latitude.

We've talked about latitude a lot.

Latitude is one of the main factors that affect biomes, particularly where they are located in relation to the equator.

For example, biomes located in high latitudes, farthest from the equator, like the taiga and the tundra receive the least amount of sunlight and have lower temperatures.

Put your finger on the taiga and the tundra right up in the most Northern part of the map.

Well done.

So those are the areas that receive the least amount of sunlight and have lower temperatures as a result.

Biomes located in the middle latitudes, between the poles and the equator, such as the temperate deciduous forest, receive more sunlight and have more moderate temperatures.

That means that they're not as extreme.

Not as hot or cold.

For example, in Europe there are- the area of land is covered with a lot of temperate deciduous or temperate broadleaf forest.

And that's because the temperature here is not as extreme as at the poles or as at the equator.

Now, biomes located in the middle latitudes or right in the middle at the equator, receive the most sunlight and therefore have higher temperatures.

But they receive high amounts of rainfall as well, which is why we see tropical rainforests and grasslands.

They receive a lot of heat and a lot of rainfall.

So that's why we have the tropical rainforest.

It's the perfect climate.

The grasslands receive less rain than the tropical rainforest but they still get the heat.

Here's a question.

The equator receives more direct sunlight than the polar regions.

True or false? Shout out your answer.

That is true.

The equator does receive more direct sunlight than the polar regions.

Well done.

Okay, now we're thinking about human activity that affects the biome.

Well, all biomes contain millions of intricate ecosystems in which living and nonliving things interact.

These ecosystems are balanced, by all of the natural activity that occurs within them.

We can see from this image that there are many living things that are interacting within a biome and then within the individual ecosystems. So, humans rely on ecosystems located within biomes to provide them with many things.

For example, fertile soil, minerals, nutrients from the food we eat, fish, and game.

Game is wild animals that are hunted for meat.

In many parts of the world humans are overfarming, overfishing, overhunting, and extracting minerals and nutrients from the land at unprecedented rates.

That means at rates never seen before in human history.

This is causing many ecosystems to become unbalanced.

For example, overfishing can unbalance the food chains that occur in the oceans.

Meaning that there is not enough food for other species and this can cause a knock on effect.

For example, tuna are a species of fish that have been hugely over-fished.

They are one of the main food sources of great white sharks.

If there are not enough tuna for the sharks to eat, sharks will suffer and they will not be able to survive in the wild.

The whole ecosystem will become unbalanced.

Answer the question.

Why shouldn't humans overfish species such as tuna? You can use the sentence starter, humans should not over-fish.

And there are some key words for you to use as well.

Tuna, species, food chains, sharks, ecosystems, unbalanced.

Pause the video now, while you complete that task.

Let's have a look at my answer and you can compare yours to mine.

Humans should not over-fish species such as tuna because animals such as sharks will not have enough food to eat.

This can cause ecosystems to become unbalanced.

Compare your answer to mine and either tick or fix your own response.

Let's move on.

So, waste.

Waste is another human activity that affects biomes.

Now, human wastes enters other natural ecosystems where it can cause them to become unbalanced.

Sometimes all of the waste can build up to harmful levels, which can destroy destroy entire ecosystems. Some examples of human waste that can affect ecosystems are household waste, industrial waste from factories, mills, mines, and other production industries, agricultural waste, such as animal manure and harmful pesticides, and gas's produced when fossil fuels are burned.

Here's a task.

Answer the question.

Using the images, describe what impact throwing plastic away may have on fish and humans.

So you have in this series of images, an image of a plastic bag in the ocean.

You then have an image of a school of fish and finally a plate of fish and chips.

Why, how do you think these images are linked? What might the fish do with the plastic bag? And what does that mean for the person about to eat the fish and chips? Pause the video now and write a description about the impact or potential impact of throwing plastic bags away on fish and humans.

Let's compare your answer to mine.

I said, if humans throw away plastic, it may end up in the ocean, where fish may mistake the plastic bag for food and eat it.

The fish may then be caught and eaten by a human, meaning that the human will also be eating plastic.

You can compare your answer to mine and tick or fix your response.

Great work everyone.

Another fantastic lesson.

If you're able to, please take a picture of your work and ask a parent or carer to share it with your teacher so that they can see all the fantastic work you've achieved.

And if you'd like, you can ask your parent or carer to send a picture of your work to @OakNational on Twitter so I can see your work too.

That's all we've got left for for today.

Thanks so much and see for our next lesson.