Lesson video

Hello, my name's Mrs. Hawking.

Today we're going to be exploring temperate deciduous forests together.

These are forests that you might find in the UK.

So many people might have explored these forests in reality near their homes.

So they're really a good one to find out more information about.

Today our lesson is the temperate deciduous forest.

It's taken from the "Forest Biomes" unit.

Why are forests so important? Our outcome today is to locate the temperate deciduous forests, describe their climate and explain the role of the nutrient cycle.

We have some key words that are useful to know before we start.

We have temperate climate zone, seasonal, climate, adapt and nutrients.

If there's any of these words that you haven't heard before or you think you might need to record, feel free to pause the video as I read them out and you can make a note of the definition.

Our first key word, temperate climate zone means the region between the tropics and the polar areas.

It's a climate zone, so the climate in that region is the same.

Seasonal means things that relate to, occur during or depend on a particular time of year.

So you will have heard of the seasons spring, summer, autumn, winter, which we experience in the UK.

Climate is our next keyword and average of weather conditions in a place taken over a long period of time, usually 30 years or more.

Then we have adapt.

This is to make changes to suit different conditions.

And finally, nutrients.

These are substances that living things need to consume in order to live and grow.

Our lesson today is in two parts.

What is the climate of temperate forests and what are the features of temperate forests? First of all, we'll start with the climate.

Temperate forests have many different seasons.

Many of the trees drop their leaves in winter, although some are evergreen.

Temperate forests are located in the temperate region between the polar and tropical regions.

You can see the polar regions identified here on our map and here's the tropical region.

Sitting in between these are our temperate regions.

You can see that the temperate forests are identified on the map in green.

Much of the UK was once covered in temperate forests.

This has now reduced to only 13%.

Here is the UK and you can see that it is definitely within that temperate forest region.

What type of forests are found in the UK? Well done.

Temperate forests.

The continents with the most temperate forests are North America, Europe, and Asia.

Time for another check for understanding.

Name three continents which contain the most temperate forests.

You can use that map to help you if you'd like.

Well done.

North America, Europe, and Asia.

The temperate forests have an average annual temperature of 10 degrees C as they're located in the temperate zone.

However, temperature varies a lot due to seasonal changes.

On the climate graph an the right we can see the temperature is shown by the red line and that is read off against the right hand axis average temperature in degrees C.

The average rainfall is shown by the blue bars and it is read off against the left hand axis average rainfall in millimetres.

Now we can see as a really broad range in temperatures, and I'm going to add on some lines just to make this a little clearer.

So the lowest temperature that is shown on the graph is 4.

7 degrees C, and the highest temperature is 17.

7 degrees C.

So you can see the range.

The difference there is quite big.

The way we can calculate how big that difference is, is by doing a simple sum.

The maximum in this case, 17.

7 minus the minimum, in this case 4.

7, and that will equal the range.

So here we have 17.

7 minus 4.

7 equals 13 degrees C.

So the range of temperature for this area shown in this graph would be 13 degrees C.

A quick check for understanding now.

What is the rainfall range shown on the graph? So this time it's rainfall, not temperature, but you need to use the same principles to work out the range.

The maximum minus the minimum equals the range.

Make sure you're looking at the correct part of the graph.

The key shows which symbols show rainfall.

Would you like me to put some lines on the graph as well to make it a little easier? Here we go.

And just in case you can't read off accurately enough, I'll pop the numbers on for you.

So this shows our minimum and maximum rainfall.

Now you calculate the range.

Pause the video if you need any longer.

Well done, good effort.

So got 68 millimetres minus 48 millimetres equals 20 millimetres.

So the range is 20 millimetres.

Well done for getting that right.

Now we're onto our practise task.

I would like you to use an atlas to identify five countries where temperate forests are found.

I've put on the slide here, the world map showing where the temperate forests are.

Remember the (indistinct) green shows us the temperate forest, and that is on the key.

Our second task I'd like you to do is to complete the climate profile table using the climate graph on the right hand side.

I would like you to fill in this table by having a look at the graph.

Remember the key will help you on the graph and we have talked about these numbers already, so hopefully that should help you with reading off the axis.

Pause the video now.

Well done.

Right, let's have a look at which countries you might have identified.

I've got a selection, but there are more.

So if yours are correct and you know they're correct, well done.

So we've chosen Chile, the USA, the UK, Germany, but there's lots of other European countries as well.

Russia, China, and Australia.

These are just an example.

Did you get any of these? Well done.

If you didn't get any of these, you might want to add some to your list.

The next task was to complete the climate profile table using the climate graph.

So these are the answers that you should have.

The warmest month should be July.

The maximum average temperature is 17.

7 degrees C.

The coolest month is January, and the minimum average temperature is 4.

7 degrees C with a temperature range of 13 degrees C.

We're now moving on to the second part of our lesson.

What are the features of temperate forests? Temperate forests contain deciduous and evergreen trees.

Evergreen trees don't lose their leaves in winter, deciduous trees do lose their leaves in winter.

The majority of trees in temperate deciduous forests are deciduous.

So notice now we've started talking about temperate deciduous forests, so a specific type of temperate forest.

and the reason we're doing that is because they're prevalent in the UK.

So just to point out, it's not just temperate forest anymore, it's temperate deciduous forest.

Jun says, "I walk home from school through the woods.

The leaves change colour and fall from the trees in the autumn.

So the woods I go to must be part of a temperate deciduous forest." That's correct.

I totally agree with that.

The temperate deciduous forest has four main layers.

The ground layer where the soil and decomposing leaves are found.

The herb layer, including herbs, grasses, ferns, and wild flowers under one metre high.

Sub canopy, which contains smaller trees.

And the canopy.

This is the highest layer made from the tallest tree tops.

Fallen leaves or leaf litter create nutrient rich soil through a process called the nutrient cycle.

Let's have a look at that in more detail.

So deciduous trees drop their leaves in the autumn and this creates leaf litter.

Leaf litter is literally the leaves that have been dropped by the tree, so it makes sense.

The trees are littering like somebody might litter.

Decomposers break down dead materials such as leaf litter, turning it into soil.

This is called decomposition.

Worms, beetles, bacteria and fungi are decomposers.

Temperate deciduous forests have more nutrient rich soil than other forests.

As trees lose their leaves, meaning there's a lot of leaf litter and the climate is not too cold for decomposers, the trees absorb the nutrients through their roots and then the cycle begins again.

So this is our nutrient cycle.

We start with the deciduous tree.

The leaf litter is then decomposed to form nutrient rich soil, which the tree roots then reabsorb.

And this is a cyclical process.

Let's do a quick check for understanding.

Rainforests must have the most nutrient rich soil out of all of the forests as the trees are so tall, and there are so many plants.

Is this true or false? You're right, it is false.

Can you tell me why? Actually the soil is richest in the temperate deciduous forest, and this is because the trees lose their leaves, meaning there's lots of leaf litter.

In addition, the climate is not too cold for decomposers, so the decomposers can survive and do their decomposing leading to the nutrient rich soil.

Well done.

I want to check a little further.

So another check for understanding here.

Complete the missing keywords to explain the nutrient cycle.

So trees drop leaves in autumn creating what? This is broken down by what? Such as worms, beetles, bacteria, and fungi.

Well done.

Trees drop leaves in autumn creating leaf litter.

This is broken down by decomposers such as worms, beetles, bacteria, and fungi.

Onto our task now.

I would like us to name the forest layers.

I've given you the definitions.

You need to name each one.

Then I would like you to draw and annotate a nutrient cycle diagram.

So that's a little bit more of a challenge.

I would like you to use the following words.

Leaf litter, decomposer and nutrient rich.

See if you can get them in there, explain how they happen, and make sure you've got that full cycle cycling round back again to the beginning.

Good luck with this.

I suggest you pause the video now.

Well done.

Right, so did you get these answers right? So the first one was canopy, the highest layer made from the tallest tree tops.

Then we have the sub canopy, smaller trees.

Then a herb layer including herbs, grasses, ferns, and wild flowers under one metre high.

And then ground layer, the soil and decomposing leaves.

The next task was the nutrient cycle diagram.

So let's have a look at this one here and make sure we've got some of the key components in our own answer.

Feel free to edit your answer as we go.

I'm going to start with the trees.

So trees drop their leaves in autumn.

This creates leaf litter.

Did you use that word leaf litter? Decomposers break down dead materials such as leaf litter, turning it into soil.

This is called decomposition.

Did you use those key terms there? Have you explained that correctly? Worms, beetles, bacteria, and fungi are decomposers.

Have you given some examples of decomposers? That would be good to use on here as well.

Next we have temperate deciduous forests have more nutrient rich soil than other forests, as there is a lot of leaf litter and it is warm enough for decomposers.

Lastly, trees absorb nutrients through their roots and the cycle begins again.

So with your images, I would suggest you have an image of a tree.

Then we have the leaves dropping from the tree or the leaves on the ground.

Then a picture of a decomposer such as a worm, and then soil, and finally, tree roots.

I'm sure you've got some beautiful diagrams. Let's have a look at the summary.

Temperate forests are distributed across Europe, Asia, and North America within the temperate climate zone.

The temperate forests have an average annual temperature of 10 degrees Celsius.

There are four layers in the temperate deciduous forest, the canopy, sub canopy, herb layer, and the ground layer.

The nutrient cycle means the soil in the temperate deciduous forest is nutrient rich.

I hope you've enjoyed learning about the temperate deciduous forest today, and next time you visit one, you will know a little bit more about the forest that are in the UK surrounding us.

Looking forward to seeing you next time.

Goodbye.