Lesson video

Hello, my name is Mr. March, and I'm here today to teach you all about "The Interdependence of Biotic and Abiotic Components in Cold Environments." So, grab everything that you need for today's lesson and let's get going.

So, by the end of today, you'll be able to explain how biotic and abiotic components in a cold environment such as soil, climate, animals, plants, and people are interdependent.

There are four key terms for today's lesson, and those are biotic, abiotic, interdependence, and evapotranspiration.

Biotic refers to the living elements of an ecosystem.

For example, the plants or the animals.

Abiotic refers to the non-living elements of an ecosystem.

For example, the water or nutrients.

Interdependence refers to the connections between different components of the environment where each component depends on or influences the others.

And finally, evapotranspiration refers to the transfer of water to the atmosphere through evaporation from surfaces and transpiration from plants.

There are just two learning cycles for today's lesson, and we'll start with the first, which is the interdependence of cold environment components.

Now, cold environments, including polar, tundra, and alpine, are all large scale biomes.

They're all large scale global ecosystems. Complex relationships exist between the biotic, which refers to the living components, and abiotic, which refers to the non-living components of ecosystems. Now, in front of you, you can see the biotic and abiotic components.

The biotic components, as I previously said, are the living things such as plants, bacteria, animals, and fungi.

Whilst the abiotic components refers to the non-living elements such as the soil, the climate, water, nutrients, and the sunlight.

Now, what are the biotic and abiotic features in this image? You might like to pause the video here and have a go yourself at trying to identify some features.

I though will start going through those different features, starting with the sunlight, which is a non-living element, and therefore an abiotic component.

We can also see small bushes, different types of vegetation, and that of course is a living component and thereby biotic.

We can also see evidence of snow or water, and therefore it is a non-living component and thereby abiotic.

We can also see mosses in the foreground.

Again, biotic life.

We can also see soil, a non-living component and thereby abiotic.

So, a quick learning check, which of these components are biotic? I would like you to read through the four options and select the two correct answers.

So, pause the video here whilst you consider, and then select your answers.

And the two correct answers were b, animals, and d, bacteria.

These are both biotic components since they are living elements.

Really, really well done if you were able to select those two correct answers.

And the next learning check is to identify the two abiotic components from the four options in front of you.

So, pause the video once again whilst you consider, and then select your two answers.

Best of luck.

And the two correct answers this time were a, water, and d, sunlight.

These are both non-living components and therefore they are abiotic.

Once again, really, really well done if you selected those two correct answers.

So, key biotic and abiotic components exist in the cold environments, and these include plants, vegetation.

This is a biotic component.

They combine also with animals, the another biotic component.

People living in the cold environments, this is again a biotic component.

And then finally we have two abiotic components, both the soil and the climate, the rain and the sunlight.

So, biotic and abiotic components are interdependent.

And interdependence means that they depend on or are affected by each other.

For example, the climate here of Antarctica may affect other elements within the ecosystem.

For example, the plants, the animals, the soil, and the people.

I would like you maybe now just to pause the video whilst you consider how the climate may affect these four different elements.

So, what did you come up with? Well, how does the climate affect plants? Well, plants need to be adapted to the low temperatures and the low precipitation.

Vegetation won't really be able to grow in those low cold temperatures and that minimal rainfall that you tend to get in polar or tundra biomes.

Therefore, the plants need to be specially adapted to deal with those conditions.

Likewise, the soil is either permanently or temporarily frozen for parts of the year, is permafrost if it's permanently frozen or temporarily frozen in those upper layer of the soil, means that the plants, the vegetation, won't have those deep roots to access the nutrients in those lower layers of soil since it'll be frozen.

Animals too need to be adapted to those low temperatures and that lack of precipitation.

And finally, as well, people won't be able to grow crops for food due to the cold and the low precipitation.

So, we can just begin to be able to identify how climate has a real effect or influence on those four different elements or components.

Time now for a quick learning check.

And it says which of the following statements about cold environments are accurate? I would like you to read through the three options.

Pause the video whilst you consider, and then select your answers.

Best of luck.

And the two correct answers were a and c.

Permanently frozen soil, or permafrost, limits the growth of deep rooting vegetation.

And c, people in polar and tundra biomes are not usually able to farm crops for food, of course, as a result of those cold temperatures there.

So, really, really well done if you were able to get those two answers correct.

So, climate change affects abiotic and biotic components because of interdependence.

Again, I would like you to consider how biotic and abiotic components may be affected by global warming or climate change.

So, pause the video here whilst you consider your own answer to that question.

Now, let's have a look at how global warming or climate change may affect plant growth.

Well, with warmer temperatures, this will increase the amount of plant that can grow.

And evapotranspiration increases, which will mean even more rainfall, and thereby lead to an even greater growth of vegetation in polar and tundra regions.

Also, warmer temperatures could mean that farming may become possible with increasing population sizes.

As these polar and tundra biomes warm up, it may attract more people to live there since it'll be a slightly easier to be able to live there.

And as a result, maybe farming may become possible of certain types of crops.

So, we'll also have soil begin to melt, that permafrost may begin to thaw out and more plant cover will increase as plants and vegetation will be able to access the nutrients in deeper soil.

So, we'll have vegetation with deeper roots and therefore more complex ecosystems with a variety of plant life due to that increased access to nutrients, also more nutrients would be added through decomposition of even greater number of dead plants.

Finally, more plants in a warmer climate would support more animals and allow the migration of new species into those cold environments.

So, once again, we can see how a changing climate will impact these four components.

So, understanding the interdependence between biotic and abiotic components in cold environments helps us understand their physical processes and how human pressures or human activities may affect them.

For example, we can see here how an abiotic component, such as the climate with the temperature and the precipitation affects how much vegetation can grow, for example.

Whilst the amount of vegetation actually influences the climate, for example, the amount of evapotranspiration that will lead to a greater or lesser amount of precipitation in the atmosphere.

Time now for a practise question.

And it says to complete the diagram to show how soil affects and is affected by plants, animals, climate, and people in a cold environment.

If you read through the four boxes, you will notice that half of each box has already been completed, but the remaining half of each box has not.

What I need you to do then is pause the video, read through each box, and try to complete that diagram.

So, pause the video here, and best of luck.

And some feedback.

So, this is what you may have included.

So, we can say that climate affects soil because low temperatures freeze the soil, and permanently frozen soil prevents deep rooting plants from growing.

Meanwhile, soil can affect plants because a lack of soil means that less vegetation can actually survive.

Meanwhile, as well, soil affects animals because the lack of soil reduces the amount of vegetation, which means that there's limited plants for certain herbivores to be able to consume, and therefore limits the number of animals that can survive in this cold environment.

Finally, soil affects people because they cannot grow crops for food if the soil is frozen or if there just isn't enough soil to grow crops in.

So, really, really well done if you were able to include any of that in your own answers.

Run now to our second and final learning cycle.

And this is to do with the interdependence within physical systems. So, physical systems are often governed by the interdependence between biotic and abiotic components.

And there are really three examples, and these are food chains, food webs, and nutrient cycles.

And we're gonna spend the rest of the learning cycle get into grips with these three different physical systems. So, a food chain is a physical system that shows how different components are dependent on each other.

For example, at the beginning of a food chain, we have the producers.

These are plants who convert the sun's energy into sugars that the rest of the food chain can then use and consume.

So, this is a biotic life form.

Then we have the primary consumers.

These are typically herbivores, plant eaters.

So, again, this would be a biotic life form through animals.

After this, then we have the secondary consumers, again, a biotic component being that they are animals.

These are secondary consumers though in that they consume the primary consumers, therefore because they're most likely eating herbivores, this makes the secondary consumers carnivores.

After the secondary consumers, we again have a biotic component with yet more animals with a tertiary consumers.

These are typically your top predators within a food chain or indeed food web.

And then finally, we have the decomposers.

This, for example, might be bacteria, fungi, and insects, and again, a biotic component.

But these are the organisms which break down dead or decaying organic matter.

So, let's do this in a little bit more detail.

So, producers, this again would be the plants, that biotic component, they depend on the sun for its energy, and which is an abiotic component, that sunlight, and also the water, they depend on that abiotic component.

And finally, they depend on the soil for its nutrients, again, an abiotic component.

So, in this way we can see how the produces, which is a biotic component, are dependent on three abiotic components.

Similarly, the primary consumes then, which are a biotic component, they are herbivores, they are dependent on vegetation, plants, which again is a biotic component, but they're also dependent on the abiotic component, which feed that plant, which they eat for their own survival.

So, for example, they're relying on the abiotic components of sunlight, soil, and water for that plant to grow so that they can then consume that.

Secondary consumers, these would be your carnivores.

So, again, they're a biotic component.

And again, they're depending on a mixture of biotic and abiotic components 'cause they're dependent on primary consumers who are also dependent on the producers.

And the producers are then dependent on abiotic components such as the soil and the water.

Likewise, any animal which needs to drink water is therefore reliant on water, which is an abiotic component.

Finally, the tertiary consumers, they're again, a biotic component.

And much like the the way in which the secondary consumer is reliant on a mixture of biotic and abiotic components, the tertiary consumers also are.

And then finally the decomposers.

They depend on a supply of dead organic matter.

So, for example, the dead producers or the plants, or in fact the dead consumers, whether that's a primary or secondary or tertiary consumer, they are all dependent on a constant flow of this dead or decaying organic matter.

So, we can begin to see how biotic components are all dependent on abiotic components as well as other biotic components.

So, a learning check.

And I would like you to add the terms to the correct place in this food chain.

Now, there are five steps and two have already been done for you.

What I'd like you to do is read through the three options, look at a, b, and c, and select what you think is the correct answer.

So, pause the video here please.

And the correct answers were, so, a is at the beginning of the food chain.

So, we have our producers.

This is then by the primary consumers.

Following the primary consumers, we have the secondary consumers.

This then is followed by the tertiary consumers.

And then finally at the end of the food chain, we have the decomposers, which returns all those nutrients from dead or decaying organic matter back into the soil for producers then to reuse.

Really, really well done if you were able to get those three answers correct.

So, in front of you then is a food web, which again is a physical system and is a complex web of biotic components.

By which I mean, in this example, plants and animals.

And again, it shows us the interdependence within cold environments.

What do I mean? Well, if I start by identifying the producers at the base of the food web, we can see that these are grass lichen and the arctic wildflower.

Then if I add in the animals located in this food web, we can begin to see the primary consumers, the secondary consumers, and indeed the tertiary consumers.

What we can begin to look at, for example, with the Arctic hare is how the Arctic hare is dependent on those producers for its own survival.

For example, we can see that it consumes grass, we can see that it consumes lichen, and we can see that it consumes Arctic wildflowers.

So, this is the herbivore in this food web.

But then the hawk as well as the polar bear and the Arctic wolf are all dependent on that Arctic hare for its own energy needs.

They consume the Arctic hare since they are secondary or tertiary consumers in this example.

So, in a roundabout way, the hawk, the polar bear, and the Arctic wolf are dependent on the grass, the lichen, and the Arctic wolf, since the Arctic hare, which is what they consume, also consumes those three producers.

So, we're beginning to see how different life forms within a food web are all interconnected.

They're all interdependent.

Now, whilst the food web does a great job in showing how life forms biotic life, living life forms are interdependent, not shown in a food web, are the abiotic components such as climate, soil, and water.

And it has to be mentioned that the biotic components in this food web, so, the plants and the animals, all depend on those abiotic components, which I mentioned just a moment ago.

So, a quick learning check, a food web shows the interaction between abiotic and biotic components in an ecosystem.

What I'd like you to do is pause the video whilst you consider and then select your answer.

And the correct answer was false.

Now, again, I would like you to pause the video whilst you consider as to why this statement is false.

And the reason is false is because a food web shows the interdependencies between biotic components only and does not include abiotic components.

However, it must also be said that all plants and animals do rely on abiotic components, although the food web doesn't show this.

So, really, really well done if you were able to identify those two correct answers.

Run now to our last physical system, which is the nutrient cycle.

Now, we have a diagram of a nutrient cycle taken from the tundra.

And really a nutrient cycle, basically, shows the interdependence between biotic and abiotic components and it shows the flow of nutrients.

Now, the nutrients are cycling between three different stores.

The first is the soil store as represented by the letter S.

This is the soil.

The second store is the biomass store.

This is represented by the letter B.

And these are all the plants and animals combined.

The final store is the litter store as shown by the letter L.

And this is the dead plant and animal matter.

So, in a cold environment ecosystem, the amount of nutrients flowing through that system is very, very low.

Let's turn our attention towards this diagram where we can see those three stores that we mentioned just a moment ago.

We have the soil, we have the biomass, and we have the litter.

Now, the circles are all proportional as in the larger the circle, the more nutrients that are stored there, and the smaller the circle, the less.

So, within this example of a tundra biome nutrient cycle that you can see in front of you, the soil store's holding the most, the biomass the second most, and the litter store the least.

Now, something has to be said about the litter store because this is abiotic because it contains that dead organic matter which is decaying.

So, it is non-living.

Let's have a go at this learning check.

It says, true or false, litter in the nutrient cycle is considered biotic.

What I'd like you to do right here is pause the video whilst you consider and then select your answer.

And the answer is false.

Now, again, I would like you to pause the video whilst you consider as to why this statement is false.

And the reason it's false is because litter in the nutrient cycles considered abiotic because it consists of non-living material, such as dead leaves and decomposing matter.

Although it's originated from living organisms, once it becomes litter, it is then classified as non-living.

So, really, really well done if you were able to identify those two correct answers.

Let's have a look at this tundra biome nutrient cycle and look at the inputs, outputs, and transfers.

So, the first thing that we need to mention is that in the tundra biome, the precipitation is extremely low as represented by this thin arrow you can see in front of us.

So, it's not really getting many nutrients in the tundra from the rain.

The lack of water and cold temperatures also means that few plants can survive that.

As a result, the biomass store is very, very small.

Now, due to the relatively arid and extremely cold conditions, there is also very little biomass, meaning the litter store is also very small.

It makes sense.

If the temperatures are very cold and there's minimal rainfall, there's not gonna be much plant growth or animal activity, and therefore the biomass store is very, very limited.

But as a consequence also, the litter store is also very limited since this is essentially dead organic matter, plant and animal matter.

Now, looking at the nutrient cycle in front of you, we can see that the soil store is the largest in terms of nutrients.

The soil storing the tundra is bigger than the biomass or the litter because of the following reasons.

The first reason is that the soil is continuously frozen, which traps most of those nutrients.

The plants are unable to access and absorb those nutrients because it is frozen.

Second of all, there just aren't that many plants to be able to take nutrients outta the soil store.

And finally, decomposition takes a long time.

But why does decomposition take a long time? It's because decomposition and decomposers depend on water and above all, above freezing temperatures, both of which are not really found in the tundra biome.

The arid and cold conditions make decomposition of litter very slow in tundra biomes.

However, it has to be said that tundra still has low nutrient soils.

This is because there is little biomass to add nutrients to them.

So, although the soil store is the largest in terms of this tundra nutrient cycle, I do not want you to think that it means that there is a huge store of nutrients there.

This is not true, okay? There are still limited nutrients in that store.

It just happens to be more than that's found in the biomass or the litter store.

Finally then, littering, which is the dead material, which falls from trees, for example, leaves or perhaps dead organic matter, dead animals, has a large thick arrow in the cold environments because this is the most important process for nutrient cycling.

The runoff has a small, thin arrow here, these are nutrients which are lost from the system, and it has a thin arrow because the lack of rain means it is rare for nutrients to be washed out of this ecosystem in this way.

However, with climate change causing permafrost to increasingly melt, you are gonna start to see this arrow become thicker and thicker since this is becoming more and more frequent.

So, a quick learning check, freezing temperatures means what for the nutrient cycle in a cold environment? I would like you to read through the three options, pause your video whilst you consider, and then select your answers.

Best of luck.

And the correct answers were b and c.

So, b is that a larger soil store as nutrients are frozen and trapped in the soil.

And c, a small biomass store due to the extreme low temperatures and lack of nutrients.

So, really well done if you were able to identify those two correct answers.

Each individual plant or animal in cold environments can be seen as part of the nutrient cycle and as part of the food chain or food web.

For example, this reindeer lichen relies on the soil, first of all, for nutrients, but also stabilises the soil through its root.

So, there's a real exchange in terms of dependencies.

Yes, the lichen relies on the soil for the nutrients, but the plant also holds that soil together to avoid erosion.

So, it is adding nutrients to the soil when that plant matter falls to the floor and decomposes, and also it's providing food for animals as part of a complex food web.

So, again, we can see how this lichen is interdependent on both animals and soil.

Run now to our three practise questions.

And the first one says, the Arctic hare is a herbivorous animal that lives in the tundra of North America.

Suggests how it is part of a food web and a nutrient cycle.

The second question says to select the correct option to complete the paragraphs below.

And the third question says, to use this diagram and explain the size of the biomass, litter, and soil stores in the tundra biome.

Use words from the diagram in your answer.

So, what I'd like you to do right now then is pause the video whilst you attempt those three questions.

And best of luck.

And now some feedback.

So, your answer for question one may have included something like this.

So, an Arctic hare is part of a food web since it will eat all the plants such as lichen and grasses, but also it will be preyed upon by larger animals like secondary or tertiary consumers, such as Arctic foxes.

It's also part of a nutrient cycle since it will be part of the biomass store whilst it's living, but when it dies, it will become part of the litter store before decomposing to add to the soil store in terms of its nutrients.

The second question needed you to select the correct option, and these were the correct answers.

So, soils in cold environments contain very low amounts of organic matter.

This is due to the biomass being so small.

Decomposition is also slow, which means nutrients take a long time to be released.

The soil store of nutrients in cold environments is larger than the biomass and litter stores.

This is because of the freezing temperatures that freeze and trap the nutrients.

It's also because of the lack of precipitation to leach nutrients out of the soil as well as the lack of vegetation uptaking the nutrients from the soil.

The third and final question asks you to use the diagram to explain the size of the biomass, litter, and soil stores in the tundra biome.

Now, your answer may have included the following.

It says, the biomass is low as the lack of precipitation, extremely cold temperatures, and inability to access nutrients in the frozen soil means plant growth is limited.

The litter store is small as the limited vegetation means that there will not be much dead plant matter.

The soil store is bigger than the other stores as there is not much precipitation to leach out nutrients and there are not many plants to take up nutrients from the soil which are frozen in the soil.

So, really, really well done if you were able to include any of that or any of the previous answers in your own.

So, a quick learning summary then.

So, interdependence in ecosystems, between climate, water, soil, plants, animals, and humans, means a change to one component will impact the others.

Food chains and food webs demonstrate the connection between living organisms and their physical environment In these regions.

Nutrient cycles highlight the interdependence of biotic and abiotic factors in cold environments.

So, really, really well done during today's lesson.

It was a pleasure to teach you, and I will see you again on the next lesson.

Goodbye!.