Our environment: Its components, Types of ecosystems, Food chains, Ecological pyramids, Significance of environment, Practice Problems, and FAQs

All living beings are made up of different organ systems. These organ systems work in harmony and carry out all the activities of the body. It is required for the well being of an organism. In the same way we live in an environment which is made up of lots of biotic and abiotic components. These components work in coordination for the sustaining of life on the Earth. If any one component is missing, it will affect the environment in a negative way.

For example, let’s imagine a situation, if you are surrounded by a cold and dark environment and there is nothing around you. How will you survive in such a condition? Yes, you will not be able to survive for a long time in such conditions, because light is an important component of the environment which is required for survival. Likewise we can not survive without components like oxygen, water, air, plants etc.

Now let’s think about our environment. It is totally different. There are a number of beautiful creatures present around us. Survival here is easy and smooth as most of the organisms are adapted to their environment. This environment provides several services to us without charging anything such as oxygen, pure water, food, sunlight and many more. Imagine, if the environment starts charging money for these services. How much can you spend? Yes, we cannot even imagine the cost.

Our environment is composed of biotic as well as abiotic components that interact with one another. The interaction between these two types of components allow survival on this planet Earth. Ecosystem is considered the unit of environment. On this planet, there are different types of ecosystems present and in every ecosystem there is a difference in the flora and fauna present. Now let’s understand more about our environment in this article.

                                                     Fig: Our environment

Table of contents

• Environment
• Components of environment
• Types of ecosystems
• Food chains
• Ecological pyramids
• Significance of environment
• Practice Problems
• FAQs

Environment

The term ‘environment’ refers to everything that surrounds us, encompassing both living and non-living objects like soil, water, plants, and animals as well as how these living and non-living creatures have adapted to their surroundings. In simple words it is the sum total of all abiotic (non living) and biotic (living) factors that surround and potentially influence an organism. The Earth's environment is what distinguishes it from other planets and makes it habitable. The term ‘environment’ derives from the French word ‘environ’ which refers to ‘surrounding’. The environment is the foundation of the biosphere because it determines the health of the entire planet Earth.

Branches of biology deals with the environment

Environmental science and Ecology are the two common branches of Biology, which deal with the study of organisms, their interactions with other organisms and with their environment.

Components of environment

The components of the environment are broadly classified into two categories as follows:

• Biotic components
• Abiotic components

Biotic components

Biotic components include all living organisms, such as plants, animals, algae, fungi, bacteria, viruses, etc., and their waste materials. The biotic components are further classified into various categories as follows:

• Producers
• Consumers
• Decomposers

                                         Fig: Biotic components of the environment

Producers

They are also known as autotrophs. Producers are those organisms that prepare their own food with the help of inorganic substances and solar energy. Producers like plants prepare their own food through a process called photosynthesis. Examples include plants, chemoautotrophs, and phytoplanktons.

                                                                          Fig: Producers

Consumers

They are also known as heterotrophs. Consumers include those organisms that directly or indirectly depend on producers for their food. They are further categorised into four groups such as herbivores, carnivores, omnivores, and parasites.

                                    Fig: Consumers

Decomposers

These are a type of organisms that feed on the dead and decaying matter for their nutrition. They include saprophytes and scavengers.

                                          Fig: Fungi

Detritivores

These are animals which feed on freshly deposited detritus and fragments left over by scavengers and help in fragmenting and pulverising it. Examples include millipedes, earthworms, beetles, etc.

                                          Fig: Earthworm

Abiotic components

Abiotic components include all non-living things present in the environment, such as air, water, soil, humidity, temperature, etc. They are essential for the survival of biotic components. Both biotic and abiotic components interact with each other to form an ecosystem.

                                       Fig: Abiotic components of the environment

Types of ecosystem

An ecosystem is a functional unit of nature, where living organisms interact among themselves and also with their physical environment. Living organisms interact with one another as well as with non-living elements such as soil, water, air, weather, and climate. Therefore, an ecosystem is described as a mixture of biotic and abiotic components. Ecosystems are classified into two types mainly:

• Natural ecosystem
• Artificial ecosystem

Natural ecosystem

A natural ecosystem is one that is created by nature without human involvement and exists naturally. Examples of the natural ecosystems include forests, grasslands, lakes, deserts, mountains, oceans, rivers, etc. All living and non-living entities occur freely in nature. Each and every component interacts with one another and works as a unit through physical, chemical, and biological processes in an ecosystem.

                                 Fig: Natural ecosystem

Artificial ecosystem

Artificial ecosystems are structures created and maintained by humans in which biotic and abiotic elements are designed to interact with one another for existence. Without assistance from humans, it is not self-sustaining and could deteriorate. Aquariums, farms, zoos, and other similar structures are examples of artificial ecosystems.

                                           Fig: Artificial ecosystem

Common types of ecosystems

There are several types of ecosystems on the Earth. Some are listed below:

• Tropical rainforest ecosystem
• Desert ecosystem
• Temperate forest ecosystem
• Tundra ecosystem
• Savanna ecosystem
• Grassland ecosystem
• Mountain ecosystem
• Marine ecosystem
• Freshwater ecosystem

Rainforest ecosystem

The atmosphere in the areas near the rainforests is really fresh because around the entire area, this ecosystem is surrounded by lush greenery. The ecosystem of the rainforest is dense due to the abundant rains due to which different varieties of plants and animals can be found. Tropical rainforests are characterised by over 200 cm of rainfall per year and they are very warm with an average daily temperature of 28°C. The temperature never drops below 20°C and rarely exceeds 35°C. Since tropical rainforests have so many plants, there is lots of transpiration (loss of water in the form of water vapour). Water vapour hovering over rainforests leads to more rain. In addition to this it is near the equator, availability of temperature and water are higher. Examples of organisms include trees like teak and animals like lions, tigers etc.

                                            Fig: Rainforest ecosystem

Desert ecosystem

The desert ecosystem can exist in the arctic as well as the tropic region. Contrary to popular opinion, not all deserts are hot, some deserts are usually windy. The remarkable characteristic of this ecosystem is the amount of precipitation it receives, which is the lowest of any other type of ecosystem. Deserts are characterised by less than 50 centimetres of rainfall annually. This ecosystem is extremely hot during the day and very cold at night. By the time the wind gets into deserts, it has little moisture. If rain falls also, it stays dry in deserts because the sand absorbs the water. Some deserts are made up entirely of rocks, while others feature sand dunes. Despite the extremely rare flora, highly adaptable insect and animal species can be found here. Examples of organisms include plants like cactus and animals like camels, snakes, desert lizards etc.

                                                         Fig: Desert ecosystem

Temperate forest ecosystem

In temperate regions, the flora of the forest ecosystem might be either deciduous, coniferous, or a mix of the two. Temperate forests receive about 70 to 250 cms of precipitation annually. The climate of a temperate forest is highly variable depending on the location of the forest. The climate of temperate forests is wet normally. These ecosystems occupy the second position in the amount of rain received. They often have two distinct seasons like one long wet winter, and a short drier summer. Organisms include plants like maple and animals like raccoons, porcupines etc.

                                      Fig: Temperate forest ecosystem

Tundra ecosystem

Polar regions at relatively lower altitudes are characterised by tundra ecosystems. It is distinguished by extreme environmental features similar to those found in deserts and is frequently treeless, windswept, and blanketed in snow. Tundra biomes get less than 25 cm of precipitation annually. Tundra biomes are characterised by less rainfall. This biome is the coldest of all biomes with the topsoil layer covered by snow most of the time. It has extremely cold temperatures (-34 to - 6 degree celsius). It is literally too cold for precipitation to fall as rain. The soil is always frozen, and during the brief summers, snow melts to create shallow ponds, which in turn give rise to lichens and tiny flowers. Examples of organisms include plants like grasses and animals like polar bears.

                                             Fig: Tundra ecosystem

Savanna ecosystem

There is a common perception that savannas are similar to deserts. The only difference between the savannas and desert ecosystems is that the savannas receive a little amount of rainfall which supports the life of the flora and fauna.

                                              Fig: Savanna ecosystem

Grassland ecosystem

The grassland ecosystems exist in the Steppes, Savannas, Pampas, Veldts, Tussocks, Downs and prairies in tropical as well as temperate regions. Grasslands or prairies are found in North America, Asian steppes, veldts in Africa, etc. They have different names. These ecosystems get too little rainfall for trees to grow in great numbers. These regions receive a good amount of sunlight and high temperatures. The flora predominantly consists of grasses. The fauna include grass-eating herbivores.They have a prevalent feature of semi-aridity and can be found in colder regions. These ecosystems are typical for grazing animals.

                                                 Fig: Grassland ecosystem

Mountain ecosystem

The animal and plant life in the mountain ecosystem is incredibly diverse. The alpine vegetation, however, makes it difficult to survive in the mountain ecosystem. Alpine tundra face the minimum mean annual temperature. Alpine biomes are relatively cold places with harsh climates, high altitudes and complex topography and are found in the Himalayas in Asia, Scottish highlands, Scandinavian mountains, etc. The animals that exist in higher altitudes are covered with long and thick fur that protects themselves from cold. Moreover, the animals undergo a long period of hibernation. Examples include yak, mountain goats and elks.

                                             Fig: Mountain ecosystem

Marine ecosystem

The aquatic ecosystem that contains saltwater and is home to a variety of species is known as the marine ecosystem. This ecosystem is considered as the vast and the biggest ecosystem on the Earth. Along with the marine beds, they also embed salt marshes, tidal zones, saltwater swamps, mangroves, coral reefs, and other natural areas.

                                             Fig: Marine ecosystem

Freshwater ecosystem

In contrast to marine ecosystems, the term ‘freshwater ecosystem’ refers to an aquatic ecosystem that contains potable water. Freshwater ecosystems are those that can be found in lakes, ponds, rivers, springs, and freshwater swamps. Planktons, algae, insects, amphibians, and underwater plants are all seen here.

                                                     Fig: Freshwater ecosystem

Food chain

Food chain is described as a chronological series of organisms each depending on other organisms for food. It describes which organism in an ecosystem consumes other organisms. In a food chain, nutrients and energy are passed from one creature to the next in a sequential order. This occurs when one animal eats another. The food chain starts with the producer and ultimately ends with the decomposer. A trophic level describes the successive stages of a food chain, starting with producers at the bottom and moving up to primary, secondary, and tertiary consumers. Therefore, we can say that the trophic level is any point in the food chain.

                                                                     Fig: Grazing food chain

Trophic levels

Different organisms occupy different levels in the food chain and each level is referred to as trophic levels. In simple words, trophic level is described as the position of an organism along the food chain. For their energy needs, organisms at one trophic level rely on those at the lower trophic level.

Organisms of different trophic levels

Producers are present at the bottom or first trophic level of the food chain, synthesising their own food, followed by primary, secondary and tertiary consumers. The sun being the ultimate source of energy radiates sunlight which producers are able to utilise and synthesise the food. Consumers are dependent on plants for food. It includes herbivores (rats) that eat plants, carnivores that eat herbivores and other animals. Herbivores are known as primary consumers present at the second trophic level feeding on producers. Carnivores eat herbivores and come later in the food chain hence are known as secondary consumers. The herbivores are eaten up by secondary consumers or primary carnivores (snake) and present at third trophic level which is further eaten up by top carnivores (eagle) at fourth trophic level called secondary carnivores or tertiary consumers.

                        Fig: Different trophic levels in a food chain

Ecological pyramids

An ecological pyramid is considered as a graphical representation of an ecological parameter like amount of biomass, amount of energy or number of individuals present in various trophic levels of a food chain with producers forming the base and the top carnivores the tip. The ecological pyramids always start from the producers.

Types of ecological pyramids

Ecological pyramids are classified into three types as follows:

• Pyramid of biomass
• Pyramid of energy
• Pyramid of number

                               Fig: Ecological pyramid

Pyramid of biomass

It is a graphical representation of biomass present sequence wise per unit area of different trophic levels, with producers at the base and top carnivores at the tip. It can either be straight like in terrestrial ecosystems or inverted like in an aquatic ecosystem.

                                          Fig: Pyramid of biomass in aquatic ecosystem

Pyramid of energy

It is a graphical representation of the amount of energy trapped per unit time and area in different trophic levels of a food chain with producers forming the base and top carnivores the tip. This pyramid symbolises the movement of energy from one trophic level to another. The pyramid of energy is always erect.

                                                     Fig: Pyramid of energy

Pyramid of number

It is a graphical representation of the number of individuals per unit area of various trophic levels stepwise with producers being kept at the base and the top carnivores at the tip. The number of species that are present at each trophic level is given by this pyramid. This kind of pyramid can also be either upright or inverted.

                                        Fig: Pyramid of numbers in a big tree ecosystem

Significance of environment

Some of the significances of the environment are listed below:

• All living things in this world depend on the environment for their survival and well-being.
• Humans rely on the environment for a variety of resources, including food, water, and air.
• Environment plays a crucial role in regulating air and climate change.
• It is a source of natural beauty that provides mental and physical peace.

Impacts of human activities on environment

Many human activities are directly attributed to the disaster of the environment. Examples are listed below:

• Acid rain
• Depletion of the ozone layer
• Change in the climate
• Acidification of oceans
• Deforestation
• Pollution
• Global warming
• Disposal of hazardous wastes
• Overpopulation

Practice Problems

1. Energy enters the ecosystem through which of the following components?

1. Carnivores
2. Decomposers
3. Producers
4. Herbivores

Solution: Sunlight is the ultimate source of energy. Through the process of photosynthesis, producers like green plants are able to transform this light energy into chemical energy and make it available to the consumers of an ecosystem. Therefore, energy enters the ecosystem through producers. Hence, the correct option is c.

2. From the given list of ecosystems, identify how many ecosystems are anthropogenic?

A. Crop field

B. Desert

C. Forest

D. Ocean

E. Garden

F. Aquarium

1. 4
2. 5
3. 3
4. 6

Solution: Anthropogenic are man-made ecosystems that are created and maintained by human beings. Examples include crop fields, aquariums, and gardens. A crop field ecosystem is a type of artificial ecosystem that is created and maintained by the farmers. In an aquarium, fishes and plants can find an environment where they can grow and develop in a healthy and balanced way. Aquariums are man-made ecosystems. A community of plants, birds, and other pollinators make up a garden, which is an artificial ecosystem that functions as a whole to maintain a healthy environment. Hence, the correct option is c.

                                          Fig: Man-made ecosystems

3. Identify the statement that best defines the ecosystem?

1. It is a system consisting of only biotic components that function together as a unit
2. It is a crucial component of nature where interactions between living things and their surroundings take place
3. It is a region where only interactions between plants, animals, and other species occur
4. It is a collection of living things that exist in isolation from one another in their physical surroundings

Solution: An ecosystem is defined as a functional unit of nature, where living organisms interact among themselves and also with their physical environment. It is an area containing living organisms, such as plants, algae, fungi, and animals as well as other non-living components. Living organisms interact with one another as well as with non-living elements such as soil, water, air, weather, and climate. Therefore, an ecosystem is described as a mixture of biotic and abiotic components. Hence, the correct option is b.

                           Fig: Ocean ecosystem

4. From the given options, which one is not an abiotic component of an ecosystem?

1. Water
2. Soil
3. Sunlight
4. Decomposer

Solution: From the given options, a decomposer is a biotic component of an ecosystem because it is a living organism that feeds on dead and decaying matter. Examples include fungi and bacteria. Hence, the correct option is d.

FAQs

1. How can the environment be protected?

Answer: We can conserve the environment if we use natural resources carefully and do not damage or contaminate any of the Earth's natural habitats. To preserve the harmony of nature between the lithosphere, atmosphere, and hydrosphere, the use of Earth's resources must be limited.

2. How does the environment affect human health?

Answer: Environment plays an important role in maintaining individual health. It provides the basic needs like food, fresh air, potable water, aesthetic beauty etc. But for proper health a person needs to make sure that he takes adequate nutrition food, has financial stability.,the state of happiness and social equality. Environmental pollution can lead to health issues like heart disease, cancer, and respiratory illnesses.

3. What are the three R’s to save the environment?

Answer: The three R’s to save the environment are reduce, reuse and recycle.

• Reduce - It means to cut down the amount of wastes generated. For example, carpooling to reduce emissions.
• Reuse - It means to find out new ways to use the things that we are planning to throw out. For example, creating pots from used tyres.
• Recycle - It means turning the old and useless things to useful things. For example, recycling of papers.

4. Which are the four sorts of environmental hazards ?

Answer: The environmental hazards are classified into four categories such as physical, chemical, biological, and cultural.

• Physical hazards - These are the natural processes occurring in the environment. For example, the heat stress.
• Chemical hazards - This includes the chemical substances that have a negative impact on the environment. Examples include carcinogens.
• Biological hazards - This includes the dangerous interactions between the organisms. Examples include malaria, cholera etc.
• Cultural hazards - This include those behavioural patterns, socioeconomic status, occupations that will affect the environment. For example, smoking.

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