Ecosystem | Biology

Summary

This educational script explores the intricacies of ecosystems, highlighting the interplay between biotic and abiotic components. It delves into the roles of producers, consumers, and decomposers, elucidating the concept of food chains and trophic levels. The script also introduces the idea of energy flow and its progressive decrease through levels, culminating in the phenomenon of biological magnification, where harmful substances accumulate in higher trophic levels, impacting human health.

Takeaways

• 🌿 The environment is made up of both living (biotic) and non-living (abiotic) components that interact to form ecosystems.
• 🌳 Ecosystems are categorized into terrestrial and aquatic types, with each having specific living organisms and environmental conditions.
• 🔍 Biotic components include all living organisms, while abiotic components consist of physical factors like temperature and soil.
• 🏞️ Ecosystems are further classified into natural (forests, lakes) and artificial (gardens, crop fields) ecosystems.
• 🌱 Producers, such as green plants, are autotrophic organisms that create their own food through photosynthesis.
• 🍖 Consumers are heterotrophic organisms that obtain food from other organisms, with classifications including herbivores, carnivores, omnivores, and parasites.
• 🕊️ Herbivores, like rabbits and deer, are primary consumers that feed exclusively on plants.
• 🐺 Carnivores are further divided into secondary and tertiary consumers, with larger carnivores feeding on smaller carnivores.
• 🍲 Omnivores consume both plants and animals, with humans being an example.
• 🧪 Decomposers, like bacteria and fungi, break down dead organic matter into simpler substances, recycling nutrients back into the ecosystem.
• 🔗 The food chain illustrates the sequence of consumption among organisms, with energy and nutrients transferring across trophic levels.
• 📉 Energy flow in food chains is unidirectional and diminishes at each level, with only about 10% of energy being passed on to the next trophic level.
• 🌐 Food webs represent the interlocking of multiple food chains, showing the complex interactions between different organisms in an ecosystem.
• 🌐 Biological magnification refers to the accumulation of harmful substances like pesticides and heavy metals in organisms at higher trophic levels, posing a risk to human health.

Q & A

What are the two main components of an ecosystem?

The two main components of an ecosystem are biotic components, which include all the living organisms, and abiotic components, which include all the physical factors like temperature, wind, rainfall, soil, and minerals.

How are ecosystems classified?

Ecosystems can be classified into natural and artificial ecosystems. Natural ecosystems include forests, lakes, and ponds, while artificial ecosystems include gardens, crop fields, and aquariums.

What are the three main types of organisms in an ecosystem based on their food acquisition method?

The three main types of organisms in an ecosystem are producers, consumers, and decomposers. Producers create their own food through photosynthesis, consumers obtain food from other organisms, and decomposers break down complex organic substances.

What is the difference between autotrophs and heterotrophs?

Autotrophs are organisms that can produce their own food, typically through photosynthesis, like plants. Heterotrophs are organisms that cannot produce their own food and must consume other organisms for energy, such as animals.

What are the different types of consumers based on their diet?

Consumers can be classified into herbivores, carnivores, omnivores, and parasites. Herbivores feed only on plants, carnivores feed on animals, omnivores eat both plants and animals, and parasites derive their food from living animals.

How does the energy flow in a food chain?

Energy flows in a food chain from the sun to the producers, then from the producers to the primary consumers, and then to secondary consumers and so on. However, only about 10% of the energy is transferred to the next trophic level.

What is the concept of biological magnification?

Biological magnification is the process by which certain substances, such as pesticides or heavy metals, move up the food chain and accumulate in higher concentrations at each trophic level, especially in top predators like humans.

What is the role of decomposers in an ecosystem?

Decomposers, such as bacteria and fungi, break down dead and decaying organic matter into simpler substances, returning nutrients to the environment and facilitating nutrient cycling.

Can you provide an example of a terrestrial ecosystem?

A terrestrial ecosystem includes all the living organisms residing on land, such as forests, grasslands, and deserts, along with the non-living components like soil, water, and air.

What is the significance of the Gir Forest in the context of the Indian ecosystem?

The Gir Forest in Gujarat, India, is significant for its diverse flora, including a variety of trees and grasses, and its fauna, which notably includes the Asiatic lion, making it a crucial part of India's natural ecosystem.

How does the energy transfer efficiency in a food chain affect the number of trophic levels?

Due to the low energy transfer efficiency of about 10% between trophic levels, food chains generally consist of only 4 trophic levels, as the energy available decreases with each level.

Outlines

00:00

🌿 Introduction to Ecosystems and Their Components

This paragraph introduces the concept of the environment as a complex system comprising both biotic and abiotic elements. It explains the interaction between living organisms such as plants, animals, and microorganisms, and non-living components like temperature and soil, forming ecosystems. The paragraph distinguishes between terrestrial and aquatic ecosystems and further classifies ecosystems into natural and artificial types. It also outlines the roles of producers, consumers, and decomposers within the ecosystem, detailing the food chain and the trophic levels, from producers to various levels of consumers, and concluding with decomposers.

05:01

🐠 Exploring Trophic Levels and Ecosystem Examples

This section delves into the hierarchy of trophic levels, starting with producers at the first level and moving up to primary, secondary consumers, and decomposers. It uses examples from pond and forest ecosystems to illustrate how energy and matter flow through these systems. The paragraph highlights the abundance of individuals at lower trophic levels compared to the higher ones and introduces the concepts of flora and fauna, providing examples of different ecosystems in India, including Gir forests, Jim Corbett National Park, and Jaladpara Sanctuary. It emphasizes the role of producers in these ecosystems and how energy transfer occurs between trophic levels.

10:04

⚡ Energy Flow, Food Webs, and Biological Magnification

The final paragraph discusses the flow of energy through the food chain, noting the inefficiency of energy transfer between trophic levels, with only 10% of energy being passed on. It explains the concept of food webs, which are interlocking food chains, and uses an example to show how different organisms are interconnected. The paragraph also introduces the phenomenon of biological magnification, where harmful substances like pesticides and heavy metals accumulate in organisms as they move up the food chain, leading to higher concentrations in top predators, including humans. The summary concludes with a brief recap of the lesson's main points, emphasizing the structure of ecosystems, the roles of different organisms, and the importance of understanding energy flow and biological magnification.

Keywords

💡Environment

The environment refers to the surroundings in which living organisms exist, including both living and non-living components. In the video, the environment is the foundation for the ecosystem, encompassing plants, animals, microorganisms, and human beings, as well as non-living elements like soil and water.

💡Ecosystem

An ecosystem is a community of living organisms, such as plants, animals, and microorganisms, interacting with each other and their non-living physical environment, which includes elements like air, water, and minerals. The script explains that ecosystems can be terrestrial or aquatic and are composed of biotic and abiotic components.

💡Biotic Components

Biotic components are the living parts of an ecosystem, which include all types of organisms, from plants to animals and microorganisms. The script emphasizes that these biotic elements are crucial for the functioning of an ecosystem, as they interact with each other and with abiotic factors.

💡Abiotic Components

Abiotic components are the non-living physical factors in an ecosystem, such as temperature, wind, rainfall, soil, and minerals. The script illustrates that these elements provide the necessary conditions for life and influence the types of organisms that can survive in a given environment.

💡Producers

Producers, also known as autotrophs, are organisms that can produce their own food through the process of photosynthesis. In the script, green plants and blue-green algae are given as examples of producers, highlighting their role as the starting point of the food chain in an ecosystem.

💡Consumers

Consumers are organisms that obtain their food by consuming other organisms. The script categorizes consumers into herbivores, carnivores, omnivores, and parasites, each with a different feeding habit. Consumers are essential for transferring energy through the food chain.

💡Decomposers

Decomposers are organisms that break down dead or decaying organisms into simpler substances, returning nutrients to the ecosystem. The script mentions bacteria and fungi as examples of decomposers, which are crucial for nutrient recycling and maintaining the ecosystem's health.

💡Food Chain

A food chain is a linear sequence of organisms through which nutrients and energy flow in an ecosystem. The script describes the food chain as starting with producers and moving through various trophic levels of consumers, ending with decomposers.

💡Trophic Levels

Trophic levels are the positions that organisms occupy in a food chain, indicating their feeding relationships. The script explains that the first trophic level consists of producers, the second of primary consumers, and subsequent levels include higher-order consumers, with decomposers often at the final level.

💡Biological Magnification

Biological magnification is the process by which certain substances, such as pesticides or heavy metals, become more concentrated in organisms as they move up the food chain. The script uses this concept to illustrate how these substances can accumulate in top predators, including humans, due to their position at the top of the food chain.

💡Energy Flow

Energy flow in an ecosystem refers to the transfer of energy from the sun to producers and then through various trophic levels of consumers. The script explains that only a small percentage of energy is passed on to the next trophic level, which limits the length of most food chains.

Highlights

Environment consists of living organisms like plants, animals, microorganisms, and human beings, as well as non-living components.

Components of the environment interact to form ecosystems, which can be terrestrial or aquatic.

Ecosystems are composed of biotic components (living organisms) and abiotic components (physical factors).

Ecosystems are classified into natural (forests, lakes) and artificial (gardens, crop fields).

Organisms in ecosystems are categorized as producers, consumers, and decomposers based on their food acquisition methods.

Producers, such as green plants, are autotrophs that produce their own food through photosynthesis.

Consumers are heterotrophic organisms that obtain food from producers and are further classified into herbivores, carnivores, omnivores, and parasites.

Herbivores, like rabbits and deer, are primary consumers that feed exclusively on plants.

Carnivores, such as lions and tigers, are secondary or tertiary consumers that feed on other animals.

Omnivores consume both plants and animals, exemplified by humans.

Parasites obtain food from live animals, unlike carnivores that feed on dead animals.

Decomposers, like bacteria and fungi, break down dead organic material into simpler substances.

The food chain illustrates the sequence of consumption among organisms in an ecosystem.

Trophic levels represent the different steps in a food chain, starting with producers and followed by consumers.

Energy flow in food chains is unidirectional, with a decrease at each level due to energy loss as heat and organism needs.

Food chains interlock to form food webs, showing the complex interdependence among organisms.

Biological magnification refers to the accumulation of harmful substances like pesticides and heavy metals at higher trophic levels.

Human beings, being at the top of the food chain, are most affected by biological magnification.

Examples of ecosystems in India, such as Gir forests and Jim Corbett National Park, illustrate the diversity of flora and fauna.

The energy transfer efficiency in food chains is generally around 10%, limiting the number of trophic levels to typically four.

Transcripts

Hello students! In this lesson we will learn about our environment.

As we all know that our environment consist of living organisms like

plants, animals, microorganisms and human beings and non-living living

organisms around us.

All these components of our environment interact with each other.

These interactive organisms along with the non-living components

together form the ecosystem.

For example: Terrestrial ecosystem, Aquatic ecosystem, etc.

Terrestrial ecosystem consist of all the living organism residing on land

and all the non-living thing present around them.

Aquatic ecosystem comprises of all the aquatic organisms and their environment.

Hence, we can say that ecosystem consist of two main components,

Biotic components and Abiotic components.

Biotic components comprises of all the living organisms,

while Abiotic components comprises of all the physical factors like

temperature, wind, rainfall, soil and minerals.

Ecosystems can also be classified in natural and artificial ecosystems.

Ecosystems like forests, lakes, ponds, they all are come in natural ecosystems.

While gardens, crop fields, aquariums, they all make artificial ecosystems.

Now, lets talk about the organisms present in our ecosystem.

There are three main kind of organisms depending on the manner on which they obtain their food.

And these are producers, consumers, and decomposers.

Now, we will talk about them one by one.

Producers are the organisms that make or produce their own food by photosynthesis.

For example: green plants and blue green algae.

So, we can say that all the producers are autotrophs.

Next consumers, these are the organisms which take food from the producers.

That is, we can say that all the heterotrophic organisms are the consumers.

These consumers can further be classified into herbivores, carnivores, omnivores, and parasites.

Herbivores are the animals that only feed on plants.

For example: rabbit, deer etc. They are called the primary consumers.

Next carnivores, carnivores are the organisms that only feed on animals. For example: lion, tiger, wolf, etc.

Now, these small carnivores like wolf, dog, etc are called secondary consumers.

While large carnivores like lion, tiger etc. are called tertiary consumers,

as they feed on secondary consumers.

Now next, Omnivores,

Omnivores are the organisms which feed on both plants and animals.

For example: all the human beings.

Last parasites. Parasites also derive their food from other organisms, but the main

difference between parasites and carnivores is that

carnivores obtain their food from dead animals, while parasites obtain their food from live animals.

Next, we'll talk about the third type of organisms in our ecosystems, that is the decomposers.

These decomposers break down complex organic substances into simpler organic substances.

They mainly act on the dead and decaying materials.

For example: micro-organisms like bacteria and fungi.

As all these decomposers use organic substances for their nutrition,

so, they are also heterotrophs.

Now, we can say that producers that is, grass is eaten by rabbit that is the primary consumer,

which in turn are eaten by secondary consumers, and which further are decomposed by decomposers.

For example: grass is eaten by rabbit, which in turn is eaten by lion.

When this lion dies, it's body is decomposed by micro-organisms or the decomposers present in the environment.

This sequence of who eats whom in an ecosystem is called food chain, or

we can say that the series of organisms taking part at various biotic levels form a food chain.

Each of these steps or levels in the food chain are called trophic levels.

So, we can say that the first trophic level comprises of autotrophs or the producers.

So, in this example grass makes the first trophic level.

Now, the second trophic level, it comprises of the primary consumers.

For example deer.

Third trophic level comprises of secondary consumers. For example lion.

In simple food chains like this, decomposers form the third trophic level.

There are generally more number of individuals in the lower trophic levels than in the higher trophic levels.

It can be shown diagrammatically like this.

Let's see the chain of all these organisms in pond ecosystem.

So, here the primary producers are the plants

which are growing along the borders of the pond,

and even on the surface of the water, that is the floating plants,

and even some plants which grow under water, that is the submerged plants.

So, these plants, they make their own food and so are the producers of the food chain in pond ecosystem.

Next, these plants are then eaten by herbivores which are,

the plant eating fishes, insects, etc., and they make the second trophic level of the food chain.

Then, these herbivores are in turn eaten by larger fishes or frogs which are the carnivores,

which makes the next trophic level of the food chain,

and when all these organisms, that is both plants and animals die,

they are decomposed by numerous bacteria and fungi, which are regarded as decomposers.

Now, lets see another example which is of forest ecosystem.

Now, as we all know that forest is a large area of land with a dense growth of trees.

So, in forest ecosystem also all these trees and plants, they consist of producers which is the first trophic level.

And then, all the animals which depend on all these producers, that is the herbivores

like deers, rabbits, pigeons, parrots or even some insects like grasshoppers, butterflies, etc.,

they make the second trophic level.

And then when these herbivores are eaten by carnivores, which are the tiger, lion, wolf, lizards, snakes, etc.,

they make the third trophic level.

Now, lets see the flora and fauna of forest ecosystem.

Now, flora it means the plants which naturally occur in a particular area, and

fauna means the animals naturally living in a particular area.

Now, let's see the examples of various flora and fauna of different ecosystems in India.

First, let's see about Gir forests which are in Gujarat.

The Flora of Gir forests consist of a large variety of shady trees like peepal tree, acacia, neem tree etc.

And also some wild bushes and grasses.

And the fauna of this Gir forest, it consist of the animals like bears, dogs, cats, rats, rabbits, kites, Vulture, etc. and

and the most significant animal being 'Lion'.

Now, let's see the example of another ecosystem which is, the Jim Corbett National Park, which is present in Uttarakhand.

The flora of this Jim Corbett National Park consists of various kinds of trees, including the pine trees, shrubs and grasses.

And the fauna, it consists of various types of animals, specially the tiger.

Now, let's see about Jaladpara Sanctuary which is present in West Bengal.

The flora of this sanctuary consists of various trees including the banyan trees.

And the fauna consists of a variety of animals and birds and specially the rhinoceros.

Now, let's see the energy flow in the food chain.

As we know that autotrophs are the producers from the first trophic level in the food chain.

They make their own food and derive energy from it.

This energy then travels down to all the trophic levels. The amount of energy at each trophic level

decreases continuously.

It is found that only 1% of the solar energy that fall on the leaves of the plant is utilized to make food.

These plants are then consumed by the primary consumers. So, they get this energy.

Now, this energy is lost in the environment in the form of heat, and some of this energy is used in the vital functions

like digestion, reproduction, growth etc.

And only 10% of the energy is really utilized by the organism and so on for the next levels.

So, the secondary consumers also have only 10% of the energy to be utilized for the further trophic levels.

By this, we can say that there is a unidirectional flow of energy in food chains.

That is, the energy flows from the sun to the producer, then from the producer to the primary consumers,

then to secondary consumers and so on.

Since, very little energy is present in the next trophic level, so, a food chain generally comprises of

only 4 trophic levels.

Now, as we know that all the organisms can be eaten by many different kind of organisms,

which in turn are further eaten by many organisms.

So, we can say that all these food chains are interdependent.

So, this system of interlocking and interdependence of food chains is called food web.

For example: grass can be eaten, either by a rabbit or by a deer.

And rabbit or a deer can be eaten, either by a wolf or by a lion.

Now, as you all know that the lion can also eat the wolf.

So, this interdependence between both these food chains depict a small unit of a food web.

Now, let me tell you an interesting fact about food chain which is biological magnification.

Biological magnification is the process in which the chemicals like pesticides and heavy metals

move up to the trophic levels and get accumulated in all the organisms.

Let me explain this with an example. Farmers spray pesticides or other chemicals on the crops.

These chemicals are then washed down in the soil and in other water bodies.

From there, when plants photosynthesize, they take up these chemicals along with the water.

These chemicals are also taken up by aquatic animals. And thus, these chemicals enter the food chain.

As these chemicals are non-biodegradable, so, they get accumulated at each trophic level.

It means that these chemicals are present in the highest concentrations in the highest trophic levels.

And as we all know that human being form the highest trophic levels.

So, these chemicals are in the highest concentration in the human beings.

This phenomena is known as Biological Magnification.

Now, let's have a quick glance of the lesson.

We have studied that all the interacting organisms of an area along with the non living constituents of the environment form an ecosystem.

Ecosystem consist of two components: Biotic components and Abiotic components.

There are three kinds of organisms in the biotic component of the ecosystem.

Like producers, consumers and decomposers.

Next we studied about the food chain. The sequence of who eats whom in an ecosystem is called a food chain.

Each of the steps or levels of a food chain are called trophic levels.

Only 10% of the energy present in the first trophic level gets transfer into the next level.

Next we studied about biological magnification.

It refers to the process in which certain substances like pesticides or heavy metals move up the food chain and get accumulated in all the organisms.