Lesson video

Welcome to today's ninth and final lesson in the unit Ecosystems. Today's lesson is gonna be all about the importance of biodiversity.

My name's Mr. Jarvis and I'm gonna be teaching you today.

By the end of today's lesson, you're going to be able to explain why it's important to maintain biodiversity and to suggest how we might be able to do it.

There are four key words to today's lesson.

They are biodiversity, species, gene bank, and conservation.

The meanings of those words are all on the screen for you now.

We're gonna go through those as we go through the lesson, so don't worry, but if you want to pause the video to read through them, then you can do now.

So today's lesson is broken down into three parts.

First, we're going to be looking at what the word biodiversity means.

Then we're going to move on to talk about why it's important.

And finally the last part of the lesson and the unit is all about conservation.

And conservation is about maintaining biodiversity.

So if you're ready, let's get started with our first part of today's lesson, which is what biodiversity means.

So biodiversity is the range of different living organisms that live in a place.

The word biodiversity can be split down into two parts: bio, which relates to living things, and diversity, which means having many different things in one place.

So biodiversity is a range of living things that live in a place.

The important thing to remember about biodiversity is it's not having a lot of one type of organism in a place.

It's about having lots of different types of organism in the place.

That's the diversity part of the word.

It's important that you remember that.

So the higher the number of different organisms that there are in a place, the greater the place's biodiversity.

To measure biodiversity in a habitat, we count the different types of organisms or species that live there.

And a species is a group of organisms that are able to reproduce with each other to produce offspring that are also able to reproduce.

Here's an example.

In the pictures, we have four different species of snake.

They're all very similar because they're all snakes.

However, they're different species and they're different species, because they're not able to reproduce with each other to produce offspring that are also able to reproduce.

So here's a check.

Which of the following best describes biodiversity? Is it the variety of species, the number of individuals of each species, the variety of species and habitats, or the variety in differences within a single species? I'll give you five seconds to come up with an answer and then we'll check to see how well you've done.

The correct answer is A, biodiversity is the variety of species.

Well done if you got that right.

Some habitats contain more species, so they have more biodiversity than others.

So the arctic habitat doesn't have a very high biodiversity.

There's not many species that live there.

And one of the reasons for that is that the habitat is a really harsh place to live and very few species can actually live there.

On the flip side, we have a tropical rainforest habitat.

Rainforests have a very high biodiversity and that's because rainforests contain lots of food, shelter, and places for many different species to reproduce.

Generally, biodiversity is greatest in habitats that are found within the tropics.

So we've got a picture here that's a map of the world, and we've highlighted the Tropic of Cancer and the Tropic of Capricorn.

Between those two purple dash lines are the areas where biodiversity and habitats is usually highest.

So let's do a check.

A habitat at which position is likely to have the highest biodiversity? Is it position A, position B, position C, or position D? I'll give you five seconds.

The answer is position C.

Position C is likely to have the highest biodiversity because it sits between where the two Tropics of Cancer and Capricorn lie.

Well done if you got that correct.

Here's a practise task.

True or false, a coral reef has high biodiversity.

Is that true or is it false? Once you've decided, provide some evidence to support your answer by listing different organisms that might live in a coral reef.

You can use the image to help you.

You'll need to pause the video, write down your answer, and then when you're ready, press Play, and we'll check to see how well you've done, good luck.

What did you come up with? Well, first of all, true or false, a coral reef habitat has high biodiversity? And then provide evidence to support your answer by listing the different organisms that live within a coral reef.

The answer to the question is that it's true.

There is high biodiversity, and you can see that almost in the picture.

There's lots of different species that you can see either swimming around or on the rocks within that coral reef habitat.

So some of the organisms that you might have chosen to support you in your answer are lots of different fish species, lots of species of coral- that's the rocky looking organisms that are living on the rocks- species of seaweed, plankton in the water, sponges, anemones, starfish, jellyfish, crabs, lobsters, shrimps, turtles, sharks, whales, and many, many more.

There's lots of things you could've chosen because the coral reef has a high biodiversity.

Well done if you got any of those and extra ones yourself.

So now we're gonna move on to the second part of today's lesson, which is all about why biodiversity is important.

So if you're ready, let's go.

Humans have discovered about 1.

6 million species and scientists believe that we've discovered many of the large animals such as mammals and birds that are on the planet.

As the organisms become smaller, it's believed that there are increasing numbers of species that lie undiscovered.

Many of the most important species that carry out the hard work in keeping the planet healthy are these smaller species and often they're the species that we're not very keen on, such as the cockroaches and the moulds and fungi.

We need high biodiversity to ensure that ecosystems remain healthy.

Organisms all have important roles within ecosystems. Here are some of them.

Producers are important because they make all of the food for the other organisms in food webs.

Some organisms break down dead organisms and return important nutrients to the soil.

One example of this is an earthworm.

Pollinators help producers to reproduce and this also results in fruits and seeds which are eaten by other organisms, and bees and other insects play an important role in this.

And organisms that eat the fruit disperse seeds in their dung, and this helps plants to grow in new places.

It shows the interdependence, the inter-reliance of organisms on each other.

Producers relying on consumers and consumers relying on producers.

Biodiversity is also really important for humans to stay healthy.

This is because many of our medicines come from plants and fungi.

For example, you might not like the mould that grows on bread, but one species of mould penicillin is really, really important.

It's an antibiotic.

It helps us to fight infections when we're ill.

The natural world shelters us and protects us.

Examples of this include trees that protect homes from flooding and coral reefs and mangroves that protect the coastlines from storms. And there are positive mental benefits from being in and around the natural world.

So here's a check.

Biodiversity is important because there needs to be one main species in a habitat, humans rely on lots of different species for food and medicines, humans need to grow large fields of single crops such as wheat and rice to survive, and a high biodiversity helps to keep ecosystems healthy.

So there's two correct answers from those four.

I'll pause for five seconds while you work out which two they are, good luck.

How did you do? Let's check your answers.

So biodiversity is important, because humans rely on lots of different species for foods and medicines, and a high biodiversity keeps ecosystems healthy.

Well done if you've got both of those answers.

Let's do a practise task.

This wildflower meadow has lots of biodiversity.

There are lots of different species that you can see in the image and many others that you can't see.

I'd like you to write a short explanation of how biodiversity keeps ecosystems and habitats healthy.

You'll need to pause the video, write down your answer, and then when you're ready, press Play, and we'll check to see how well you've done, good luck.

How did you find that? Well, let's check to see if you got it right.

You were asked to write a short explanation of how biodiversity keeps ecosystems and habitats healthy.

Here are some of the answers that you could've had.

All organisms have a role to play within the ecosystem and the habitat.

A high biodiversity means there's lots of different types of food available For other organisms to eat.

Lots of flowers will attract lots of pollinators and that helps plants to produce fruits and seeds.

Some fruits and seeds will be eaten and that helps to disperse plants.

And other organisms help to break down dead organisms and return nutrients to the soil for plants to grow healthily.

Well done if you got those right and you might have had some others that you wrote down yourself.

Well done if you did.

So that brings us to the third and final part of today's lesson, and that's all about conservation.

Conservation is all about maintaining biodiversity.

So if you're ready, let's go.

Despite the benefits of a healthy planet, many human actions are destroying biodiversity.

Humans have changed and destroyed habitats for activities such as mining, grazing, crop production, and deforestation.

And humans have impacted land and aquatic habitats through the use of fertilisers and other chemicals.

Climate change is also putting huge pressure on organisms. As the planet temperatures rise, some organisms find it more difficult to survive.

In 2017, in the Great Barrier Reef in Australia, almost half the corals turned white or were bleached and died as a result of the warming of the seas.

And you can see in the picture on the right-hand side of the screen that the warming seas have killed some of the coral, the coral that's white.

Organisms are interdependent.

They rely on each other for food.

So reducing the population of corals will impact other organisms within the ecosystem because reducing the number of corals will reduce the amount of food that's available to be eaten.

So what can humans do? Well, we can cut our carbon emissions to reduce climate change.

We can find ways of using land and water that cause least damage to the environment.

We can protect habitats.

We can preserve and build biodiversity, for example, by giving nature the space that it needs to thrive through protected nature reserves.

And we can take a hands-on approach.

We can manage or conserve organisms and environments to help species to survive.

Here's a check.

Jacob explains ways in which humans have destroyed habitats and risk reducing biodiversity.

Which of the following statements do you agree with? So statement A is cutting down rainforests to grow crops destroys habitats and reduces biodiversity.

Are you sure that that's right? Do you think it's right? Do you think it's wrong or are you sure it's wrong? Choose one of the boxes.

Statement B, farmers' use fertilisers and chemicals can impact on biodiversity in rivers and seas.

Again, decide whether you think it's right or wrong and how sure you are.

And finally, statement C, human activities cause climate change, which impact on how organisms can survive.

What do you think about that one? You might want to pause the video at this point so that you can decide whether you think the statements are right or wrong and then when you're ready, press Play, and we can check your answers.

So Jacob explained ways in which humans have destroyed habitats and risk reducing biodiversity.

Which ones did you agree with? Which ones are right and which ones are not? So cutting down rainforests to grow crops destroys habitats and reduces biodiversity is right.

Farmers' use of fertilisers and chemicals can impact on biodiversity in rivers and seas is also right.

And human activities cause climate change, which impact on how organisms can survive, that's right too.

Well done if you got them all.

So humans can do good things for the environment.

Conservation involves protecting nature and the environment.

Here's an example of a landscape park protection area in Germany.

It's a nature reserve.

Conservation often involves a balance between what humans take from the environment and what organisms need to be able to survive.

There are lots of different types of conservation.

The next few slides, we'll look at some examples.

First of all, we're going to look at looking after the habitat.

This involves protecting the land completely, keeping other organisms, including humans, out.

And it might mean that we provide artificial nesting sites if they're needed.

One example that's been successful in Britain is how some rivers have been managed to help conserve otters.

Mountain gorillas have also been conserved in this way.

They're one of the rarest mammals on Earth, and populations declined as a result of habitat destruction, diseases that were caught from humans and humans hunting them for food and medicine.

The numbers are slowly increasing and they're increasing because of a number of factors and these include protecting the natural habitats and providing the protected areas for gorillas to live in, patrols by soldiers to prevent hunting, and breeding mountain gorillas in captivity in zoos.

It all costs a lot of money.

Some of that money comes from tourism.

We can also provide new habitats.

Conservation can take place in a garden if organisms are provided with things like bat and bird boxes to provide shelter and breeding places, ponds for drinking water, long grass to provide seeds and shelter, wildflower beds to provide nectar and pollen, or log piles to provide shelter and breeding places for beetles and hedgehogs.

All of these things provide a habitat.

Remember a habitat provides food, shelter, and a place to reproduce.

Many species become endangered when their habitat is destroyed and that's because they don't have the food, shelter and places to reproduce that they need.

Humans can help to maintain biodiversity through conservation of these habitats.

Humans can also support conservation through breeding programmes in zoos.

Zoos are controversial things.

Some people think that they're good.

They say things like zoos help to educate us about conservation.

They conserve endangered species.

People enjoy visiting zoos and the entry fees are spent on animals and conservation.

Other people think that animals suffer in zoos because they're living in unusual places.

They'll say things like the cages may be small and the animals get bored.

The animals may not have mates to breed and animals may not live like they do in the wild.

You may have a view.

What do you think? I'll pause for five seconds while you think for yourself.

So zoos work best when they work out how to breed organisms so that the population of endangered species can be increased.

And that work to help conserve the natural habitats of organisms is also important because that means that the organisms bred in zoos can be released back into the wild.

As populations of individual species reduce, there's also a reduction in the genetic diversity of the species and that means that the species may be less able to adapt to changing conditions.

Humans try to maintain biodiversity through the conservation of genetic material for future use in things called gene banks.

And gene banks are collections of seed, plants, and animals that are stored to protect genetic diversity.

Humans can help the conservation of plants by storing seeds in seed banks.

Seed banks are one example of a gene bank, i.

e.

, they're stores that help preserve genetic diversity, so that in the future, we may be able to help species to adapt to changing conditions.

The Svalbard Global Seed Vault is located between Norway and the North Pole in a place called Svalbard.

It contains over one million seeds from across the world.

The seeds are stored in cool and controlled conditions, which mean that they can be preserved for long periods of time.

Another form of gene bank involves storing embryos, eggs, and sperm from organisms at very low temperatures in liquid nitrogen.

This is called a cryobank.

The embryos, the eggs, and the sperm can be then thawed out in the future to help with breeding programmes.

So let's do a check.

Gene banks are used to help maintain biodiversity.

They do this by, A, storing organisms in captivity, for example, zoos, preserving species in the wild, or storing genetic material for future use.

I'll give you five seconds and then we'll check your answer.

The correct answer is C, gene bank's store genetic material for future use, and that helps to maintain biodiversity.

Well done if you got that.

We then move on to our final task of this lesson and of the unit.

The class have been thinking about designing a wildlife garden in the school to help promote biodiversity in their local environment.

Each class member has been asked to suggest something to include in the wildlife garden.

For each class member, explain how their suggestion will help to maintain biodiversity in the school grounds.

Izzy has suggested a small pond.

Alex has suggested lots of wildflowers.

And Andeep has suggested piles of logs.

You'll need to pause the video.

When you are ready, press Play, and we'll check your answers, good luck.

How did you get on with that? Well, let's see.

Each class member suggested something that they would like to include in their school wildlife garden to help maintain biodiversity in the school grounds.

Here are some of the things that you might have said.

Izzy suggested a small pond.

That would help because it would provide drinking water for animals and it provides a habitat for animals like amphibians and aquatic insects to live in.

Lots of wild flowers was Alex's suggestion that would attract insects by providing nectar and pollen and the plants would be food for some organisms. As well as food, it would also provide some shelter for organisms too.

And Andeep suggested a pile of logs.

They would provide shelter for organisms like beetles and hedgehogs and they provide a habitat for fungi and decomposers.

You may have got other advantages of adding those features to the wildlife garden too.

Well done if you did.

So that brings us to the final part of today's lesson, which is a summary of what we've covered.

During the lesson, we've seen that biodiversity is the number of different species that live in a place.

We've seen that biodiversity is important as it helps to keep habitats healthy.

It also helps to keep humans healthy by providing medicines and healthy habitats help to protect us from flooding and the natural world promotes our mental health.

Humans have a negative impact on biodiversity through the destruction of habitats and pollution of the environment, but we can take action to help maintain biodiversity through undertaking conservation activities.

This includes helping to conserve genetic diversity through seed banks and other forms of gene banks.

Thank you for joining me today in today's lesson.

I hope that you've enjoyed it and I look forward to seeing you again sometime in the future.

Take care for now.

Bye.