Lesson video

Hello and welcome to this lesson from the unit "Maintaining Biodiversity and Human Impacts".

My name's Mr. Jarvis and I'm going to be taking you through today's lesson.

Today we're gonna be looking at benefits and challenges of maintaining biodiversity.

By the end of today's lesson, you should be able to describe benefits of maintaining biodiversity and ways in which humans can work to conserve biodiversity.

There are five keywords to today's lesson.

They are biodiversity, ecosystem services, food security, sustainability, and conservation.

You can pause the video if you want to read through those definitions for yourself now, but we will go through the definitions as we move through today's lesson.

Today's lesson is broken down into three parts.

First of all, we're going to look at the benefits of biodiversity.

Then we'll move on to talk about sustainable use of resources, and finally we'll talk about how we conserve biodiversity.

So if you ready, let's get started with our first section, which is all about the benefits of biodiversity.

Humans have discovered about 2.

1 million species of organisms. Scientists believe that most of the large animals, such as mammals and birds have been discovered, but as organisms become smaller, it's believed that there are increasing numbers of undiscovered species.

Many of the most important species that carry out the hard work in keeping the planet healthy, which is the decomposers, are these smaller species.

And we've got two examples on the screen.

A cockroach, which is an insect and helps to break down dead organisms and dead plant matter, and fungus, which again break down dead organic matter.

High biodiversity helps to keep ecosystems healthy.

And remember, biodiversity is the range or number of different species that there are within an area.

All organisms have important roles to play within ecosystems. Here are some examples.

Producers make all of the food for all of the other organisms within the food chain or food web diagrams. Some organisms, such as this earthworm, break down dead organisms and dead organic matter and return important nutrients back to the soil for producers to use to grow healthily.

Pollinators, such as this bee, help producers to reproduce.

This also results in fruits and seeds, and these are important foods for other organisms. And organisms that eat fruit disperse their seeds within things like dung, and this helps plants to grow in new places.

Here's a check.

Which of the following explains why higher biodiversity is important in keeping ecosystems healthy? Is it a, organisms rely on each other for food, b, to keep nitrogen levels in the atmosphere stable, c, to make sure that water is not used up, or d, to prevent the melting of polar ice caps? I'll pause for a few seconds and then we'll check your answer.

The correct answer is a, organisms rely on each other for food.

Well done if you got that right.

All species, including humans, rely on other species, and we call this reliance interdependence.

Some examples of interdependence include food, building materials, protection, maintaining health, or reproduction.

Humans rely on a large number of species and we rely on organisms for food, for pollination of crops, for building materials such as the reeds in this roof, providing medicines, and cleaning up our waste.

How many species that humans rely on can you list, and what do humans rely on these species for? I'll pause for a few seconds, but you might want to pause the video at this point and make a list for yourself.

How many can you think of? There are many benefits that nature and high biodiversity provide to human wellbeing and quality of life, and these benefits are called ecosystem services.

Here are some examples of the ecosystem services that high biodiversity offers humans.

First of all, nature provides us with clean air and clean water.

It provides us with food, it provides us with shelter and protection.

For example, this coral reef is protecting the coastline and preventing villages that might be built there from being washed away in storms. It provides us with medicines and it helps us with our wellbeing.

It helps us by giving us days out in the local environment.

All of those ecosystem services are reliant on a healthy environment, and for ecosystems to be healthy, they need a high biodiversity.

Here's a check.

What are ecosystem services? A, places where the ecosystem is looked after, b, the benefits that nature provides to human wellbeing and quality of life, or c, conservation activities that stop organisms from becoming extinct? I'll pause for a few seconds and then we'll check your answer.

The correct answer is b, ecosystem services are the benefits that nature provides to human wellbeing and quality of life.

Well done if you that.

One of the most important ecosystem services which helps humans to have a better quality of life is having enough food to eat.

Humans eat lots of different types of food.

For example, you might eat meat or fish, you probably eat bread, you eat probably fruit and vegetables, and you may eat cereals in one form or another.

Staple foods are those foods that form part of human diets and humans eat different foods in different parts of the world.

For example, maize or corn, rice, wheat, potatoes, cassava, soybean, sweet potatoes and yam, and sorghum or millet.

Why do you think the different foods are eaten in different parts of the world? I'll pause for a few seconds to give you some time to think about it.

Many of the human staple foods are producers, and producers make their own food by the process of photosynthesis.

All animals, including humans, rely on producers for their food.

And without producers, animals would not be able to survive.

Demand for food is increasing as the human population grows, and this raises questions about food security.

Food security is being able to produce enough food to feed the human population.

Here's a quick check.

What's meant by the term food security? Is it a, being able to eat a wide range of different foods, b, having food locked away, c, growing enough food for humans to eat, or d, having supermarkets where we can provide food? I'll pause for around five seconds and then we'll check your answer.

<v ->The correct answer is c,</v> food security is growing enough food for humans to eat.

Well done if you got that.

Bees and other pollinating insect populations have declined over the past 50 years.

This is because of the destruction of insect habitats, pest species, diseases, and the use of insecticides.

Pollinators are essential for food security as they make sure that producers make the food that we can harvest and eat, for example, fruits.

Here's a check.

Which are the following are factors that threaten food security, a, a reduction in the number and diversity of pollinators, b, an increase in biodiversity in ecosystems, or c, an increasing human population? I'll pause for a few seconds and then we'll check your answer.

The correct answer is a and c.

Food security is threatened by a reduction in the number and diversity of pollinators, and it's also threatened due to the increasing human population.

Well done if you've got both of those.

Let's move to our first task of the lesson.

Most UK bees, around 90%, are what we call solitary bees.

They live on their own.

They don't live in groups.

One example is the mason bee.

These bees are commonly seen in gardens.

They often make their nests in the holes in brickwork of houses.

Mason bees feed on the nectar of flowers, and when they feed on the nectar, they pollinate these flowers.

The number of mason bees in the UK has declined rapidly as a result of a reduction in wildflower meadows and increased use of insecticides.

I'd like you to write a short paragraph to explain why the reduction of solitary bees may impact on human food security.

You'll need to pause the video at this point, 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.

I hope that you got on okay with that short task.

I asked you to write a short paragraph to explain why the reduction of solitary bees may impact on human food security.

You might have come up with some of the following.

A reduction in solitary bees means that the number of pollinators is reduced, and humans rely on many crops for food that are pollinated by bees, and if the crops are not pollinated, there'll be less food for humans to eat, and that will impact food security, and as a result of that impact on food security, it could result in a reduction in the human population.

Well done if you got some or all of those points in your answer.

That brings us to the second part of the lesson today, which is all about sustainable use of resources.

So, if you're ready, let's move on.

As the human population increases, there's an increased demand for food and other resources, and as a result, humans are using up the resources, destroying habitats and reducing biodiversity, and depleting populations that we use for food, such as fish.

Many of the resources humans use are finite, i.

e.

, they have an end.

Humans need to ensure that there is sustainability in the use of these resources, and sustainability is when a resource is being renewed at the same rate that it's being used.

Here's an example from a box of tea, and we can see that it has this FSC logo on it.

That indicates that the wood or the paper comes from a sustainable source, and that means that as the trees are cut down to make the paper, new trees are planted in their place.

Examples of human sustainable use of resources include reforestation to replace those trees felled for wood or paper as seen in the previous slide, fishing quotas and farming fish to help sustain the wild fish populations, and farming that maintain soil fertility.

Let's move to a check.

Which of the following are examples of resources being used in a sustainable way, a, farmers creating large fields of wheat for food, b, planting new trees to replace ones being failed for building materials, or c, replacing nutrients in the soil using manure and other organic waste? I'll pause for a few seconds and then we'll check your answer.

The correct answers are b and c.

Planting new trees to replace ones being felled for building materials and replacing nutrients in the soil using manure and other organic waste are ways of us using resources in a sustainable way.

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

That brings us to task B.

Humans use wood from trees for many uses, including making building materials and cardboard production.

I'd like you to explain how forest trees can be harvested in a sustainable way and the impact that this has on biodiversity.

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

Good luck.

So, I asked you to explain how forest trees can be harvested in a sustainable way and the impact that it has on biodiversity.

I hope that you got an okay answering that question.

You might have suggested in your answers, as forest trees are cut down to use for building materials, new trees are planted to replace them.

Only part of the forest is cleared at any one time, so there's still habitat in which organisms can live, and this means there's less impact on biodiversity levels than deforestation might cause.

Well done if you've got those right.

That brings us to the third and final part of today's lesson, which is all about conserving biodiversity.

So, if you're ready, let's carry on.

Humans can do good things to maintain biodiversity through conservation, and conservation is the process of protecting biodiversity and the environment.

Humans can help protect biodiversity at an ecosystem level, a species level, and at a genetic level.

At an ecosystem level, conservationists try to change the behaviours of humans, for example, reducing the use of fossil fuels and limiting the impact of climate change, for example, turning radiators down by a degree or so, and by recycling materials to prevent land use being used for landfill.

These types of actions help to protect habitats and to conserve biodiversity.

Here's a check.

Which of the following human behaviours is likely to result in a loss of biodiversity, a, turning down our heating by one degree C, b, protecting areas of land from urbanisation, c, not recycling materials that humans use, or d, farmers combining lots of small fields into one huge field growing a single crop? I'll give you a few seconds to think about which answer you're gonna choose and then we'll check to see if you got it right.

And the correct answers are c and d, not recycling materials that humans use and farmers combining lots of small fields into one huge field growing a single crop is likely to result in a loss of biodiversity.

Well done if you got both of those.

Conservation at habitat or ecosystem level involves a balance between what humans take from the environment and what organisms need to survive.

So protecting habitats, for example, as nature reserves help to provide organisms with the things that they need to survive.

Conservation efforts can occur at species level and they can involve actions such as protecting and regenerating rare habitats.

For example, coral reefs and heathlands, and the British otter has now started to increase in numbers as a result of conservation efforts to protect their habitats.

A reduction in deforestation and carbon dioxide emissions, providing new habitats, for example, creating wild flower meadows, breeding programmes in zoos to help prevent the extinction of species, and introducing laws to protect species that are threatened, for example, through the use of fishing quotas.

Here's a check.

Species can be conserved by a, introducing laws to protect a species and habitat.

b, protecting habitats as nature reserves, c, using more fertilisers and pesticides, or d, building new roads and houses.

I'll pause for a few seconds while you think about which of the answers are correct, and then we'll see how well you've done.

The correct answers here are a and b.

Species can be conserved through introduction of laws to protect species and habitats, and by protecting habitats as nature reserves.

Well done if you've got both of those.

As populations of individual species reduce, there's also a reduction in the genetic diversity of the species, and here in the we've got genetic diversity being shown through the range of different colours of these (indistinct).

However, as genetic diversity reduces, it means that a 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 seeds, plants, or animals that are stored to preserve genetic diversity.

Humans can help the conservation of plants by storing seeds in seed banks, and seed banks are one example of a gene bank.

The Svalbard Global Seed Vault, located between Norway and the North Pole, contains over one million seeds from across the world.

They're stored in a really cold environment, which helps to preserve them, but it means that those seeds are available for us to use in the future should we need to help with conservation efforts.

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

This is what we call a cryobank, and these can be then thawed out in the future and hopefully will help with breeding programmes.

Here's a check.

Gene banks help to maintain biodiversity by a, storing genetic material for future use, b, preserving species in the wild through conservation, or c, keeping organisms in captivity such as zoos? I'll pause for a few seconds and then we'll check your answer.

The correct answer is a, a gene bank helps domain biodiversity by storing genetic information for future use.

That brings us to our final task of today's lesson.

Some scientists estimate that up to 40% of plant species may be at risk of extinction.

Seed banks can be used to store seeds for a long period of time.

Here's a picture of the Millennium Seed Bank Project in the UK.

I'd like you to do two things.

First of all, I'd like you to explain why plants can be conserved using seed banks, and then I'd like you to describe why conservation efforts such as seed banks are important.

You'll need to pause the video, write down your answer, and then when you are ready to check them, press play and we'll see how well you've done.

Let's see how you did.

First of all, I asked you to explain why plants can be conserved using seed banks, and you may have included in your answer that seeds are small and easy to collect.

They can be dormant for long periods of time and they can be stored easily because they're small and they can be stored at low temperatures.

Secondly, I asked you to describe why conservation efforts such as seed banks are important.

And here you might have included that conservation efforts help to conserve biodiversity, and therefore help to reduce extinction.

You might have included that organisms are interdependent and so rely on each other, for example, for food.

You might have said that it helps to maintain healthy ecosystems, or you might have said that it helps to support human food security and ecosystem services.

Well done if you've got any of those in your answers.

That brings us to the summary of today's lesson.

We've seen that high biodiversity is important for maintaining healthy ecosystems. We've seen that ecosystem services are the benefits that nature bring to human wellbeing and quality of life.

These are greater when biodiversity is high.

We've seen that biodiversity is important in ensuring that humans have food security, that's having enough food to feed the human population.

Sustainability is important to ensure that resources that humans use are replaced at the same rate.

And we've seen how conservation efforts can help to maintain biodiversity at an ecosystem, a species, and a genetic level.

As always, it's been great having you alongside me during the lesson today.

I hope that you've enjoyed it and I look forward to seeing you again soon.

Bye-bye.