Introduction
Environment generally means our sorroundings. The term environment has been derived from the French word “environer” which means “to surround” or “to encircle.” Thus environment means our sorroundings i.e. anything which is around us. There are two main components of the environment (a) Biotic (living) and (b) Abiotic (non-living) components. Biotic component is further sub-divided into (I) Flora or Plant Kingdom and (II) Fauna or Animal Kingdom. Abiotic component is also further sub-divided into (I) Renewable and (II) Non Renewable sources of energy.
Environment includes each and every thing which is around us be it living or non-living. It is whatever we see in our daily lives around us like plants, animals, birds, etc. There are different kinds of things in the environment which are diverse in nature or is different from one another. But each and every thing has an important role to play in the environment be it living or non-living.
The importance of each and every thing can be explained with the help of how they are dependent on each other. Human beings inhales oxygen and exhales carbon dioxide. On the other hand, plants inhales carbon dioxide and exhales oxygen. In this way each and every things in the environment are dependent on each other. We are dependent on plants for food. There are some animals, who are dependent on the flesh of other animals for food. Water is essential for each and every living beings. In fact, there can be no life without water.
In this way each and every things in the environment interact with each other for their survival. Each and every thing has an important role to play in the environment.
The need for Afforestation
Trees are the longest living things in our earth. It keeps our environment green and clean. It gives us oxygen without which it is impossible for animals to survive. At the same time, all animals are dependent on plants for food either directly or indirectly. In this way, each and every thing has a very important role to play in the environment.
Trees and plants are one of the one of the main reasons why mankind has come into existence. The importance of planting trees should be emphasized. This is because of the numerous benefits they offer.
They make the world a better place to live in. They exhale oxygen and inhale carbon dioxide to maintain the ecological balance in the environment. They also absorb harmful gases and also give us fresh air to breathe.
Trees build a sheet to protect us from the harmful ultraviolet rays. Not only this but also they serve as a habitat for birds and various species of animals. Trees help in controlling water pollution and preventing soil erosion.
The places inhabited by a large number of trees are quite cooler compared to the concrete areas, that can’t do without air conditioners. Unfortunately, urbanization is leading to clearing of forests and plants despite the numerous benefits they offer. The only way left to prevent them and utilize these benefits is by growing them at a faster rate.
Today, our environment is facing a crisis mainly due to several threats from different sources. Our environment is facing a grave threat mainly due to several kinds of man-made problems like rapid industrialization, urbanization and so on. It has lots of negative impacts in the environment like air pollution, sound pollution, soil pollution, water pollution and so on.
Types of Environment
Natural Environment
The natural environment consists of four realms – lithosphere, atmosphere, hydrosphere, and biosphere.
Lithosphere
The lithosphere or the crust is the outermost solid layer of the Earth. This is where we live. This crust is not one continuous piece. It is more like a slightly cracked eggshell with a number of solid blocks or plates.
The crustal blocks are of two types – continental and oceanic. The continental crust lies below the landmass. Its thickness varies between 40 km and 100 km. The oceanic crust lies below the oceans and it is only about 6 km thick.
The Earth’s crust is made up of different types of rocks. On the surface, we find the thin layer of soil which allows humans to grow crops. Beneath the surface, there are important resources such as oil, coal, iron ore, and natural gas. The surface of the Earth is not even. We find different landforms such as mountains, plateaus, and plains.
Atmosphere
The atmosphere is the layer of air that sorrounds the earth. This air is a mixture of gases such as nitrogen (78%), oxygen (21%), carbon dioxide (0.6%), and other gases. This layer is thicker near the land surface and thinner at higher levels. As we know, there are five main layers in the atmosphere- troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
The atmosphere is the most important layer that helps live survive on Earth. It helps us to breathe. Its ozone layer protects us from the harmful ultraviolet rays of the Sun. Plants obtain their supply of nitrogen and carbon dioxide from this layer. It is here that all weather occurrences such as storms, rain, snow, etc. take place. We obtain water from the atmosphere.
Hydrosphere
The hydrosphere consists of all forms of water on our Earth. The oceans, seas, lakes, rivers, streams, waterfalls, water vapour (in the air), glaciers, ice, and snow are all parts of the hydrosphere.
The rivers and oceans are sources of food and minerals, and also allow transportation on their surface. Besides, we know how important water is in our daily life. We need water for domestic use, farmers need water for their crops, and industries need water for manufacturing.
Biosphere
The biosphere includes forms of all life on Earth. We find life forms on the surface of the Earth’s crust, in a few kilometres of the lower atmosphere, and deep in the oceans. The biosphere supports millions of plants, animals, and other small organisms.
Human Environment
Human interactions with the physical environment have changed the landscape in both small and big ways. Humans have influenced the physical environment in two ways – positive and negative. Often, these two overlap. For example, humans have cleared forests (negative) to make buildings to live in and work (positive). The construction activities of humans have changed the natural landscape. Similarly, quarrying activities of humans for minerals (positive) have left gaping holes in the natural environment, increasing the possibility of soil loss and landslides (negative). Dams are built across rivers to control floods – this again changes the landscape – but they also provide water and hydroelectric power.
People have controlled their environment in many other ways as well. Plants have been cultivated in places which are far from their natural habitat. Nature’s wealth have been converted into resources, that have helped build the world we live in today. Pollution is one of the most negative impacts on the environment.
Interdependence in the Environment
The realms of the natural environment are not separate units, but are interlinked. This interrelation is seen in the biosphere. It is here that all interactions take place.
Life on the biosphere is dependent on the soil of the crust on the lithosphere, on air from the atmosphere and the heat of the Sun through it, and rivers, lakes, rain, or snow from the hydrosphere.
In the ocean or hydrosphere, the biosphere is dependent on the dissolved nutrients of the lithosphere in its water, air from the atmosphere, and the very habitat of the ocean.
Balance of nature is the relationship between all parts of the biosphere, which interact with each other to maintain stability or balance within nature. This balance is very delicate and can be easily disturbed by human activity.
The sun is the most important source of energy for the earth. Plants make their own food by photosynthesis. In this process, water and carbon dioxide combine in the presence of sunlight. The energy of the sun is stored in the compounds formed as a result of this combination. Various other salts are also combined with these compounds resulting in the formation of food materials in the plants.
Plants are, therefore, known as producers. As they prepare their own food, they are called autotrophs.
Animals depend for their food on plants. These animals are known as consumers or primary consumers. The animals like sheep, goat, cattle which graze grass, eat plants and plant products are called herbivores.
Some animals live on the flesh of other animals. These are called carnivores. Animals like tiger, lion, frog, snake, woodpecker eat flesh of the animals. Carnivores are known as secondary consumers as they depend upon animals (primary consumers).
As all the food materials come from plants, all the living beings directly or indirectly depend on plants for their food.
A few organisms depend on dead and decaying substances. They cause decomposition and disintegration of these substances. These are known as decomposers. Some types of becteria are decomposers.
Ecosystem
Ecosystem is a group of plants and animals, and the physical environment with which they interact, such as water, soil, rocks, etc. Every element in the ecosystem interacts with other elements.
Each ecosystem has biotic and abiotic components which depend on each other, interact with each other, and live together in an environment that is unique. An ecosystem’s health depends on a delicate balance among its members and the environment. All the elements of the ecosystem are tied together by the heat and light of the Sun, and the weather of that region. Water is an important part of the ecosystem too.
The biosphere contains many such ecosystems. There are ecosystems on land and in water. Humans are a part of the ecosystem too. An ecosystem might be as small as a pond or as large as a desert. The larger ecosystems are also specific kinds of vegetation, such as the tundra or the tropical rainforests. In each ecosystem, the plants and animals adapt themselves to their environment.
Ecology
We have already learnt that the sorrounding in which we live is known as the environment. It includes a number of living and non-living components. The main non-living components are air, water, light, temperature and soil. The living components are animals and plants. The non-living components are called abiotic components and living components are called biotic components. No organism can live in isolation. They depend on one another for their life activities. We have already learnt that food is required by all living creatures. Green plants can prepare their own food. All herbivorous animals depend on plants for their food. Animals depend on plants for other purposes also.
The relationship between the plants and animals through food is called food chain. In the food chain, there is transfer of energy from one living organism to another, through food. Carnivorous animals use the flesh of herbivorous animals for their food. Many times big and strong animals use weak and small animals for their food. In this way, there is a long chain of the hunters and the preys.
There is a natural balance between the forest life and life in human dwellings. This balance is maintained due to the food chain. But if, for some reason or the other, even a single link of the food chain is broken, the balance in nature is disturbed. For example, as long as enough grass fodder is available in the meadows, herbivorous animals like rabbits and deer live on them. Therefore, the carnivorous animals, too, have plenty of food. But if there is scarcity of grass, the population of herbivorous animals dwindles. As a result of this, the wild animals prey upon domestic animals in nearby villages. Hence, balance of nature is disturbed. It is not only the fall in number of a particular kind of animals that disturbs nature’s equilibrium. A change in any one of these units disturbs the balance in nature.
Effect of Population Growth on the Balance in Nature
Population and natural balance are irrevocably inter-related. As population increases beyond limits, it becomes more difficult everyday to meet its needs for food, clothing and shelter. More agricultural land gets used for building shelters and in the attempt to grow more crops from less land, the land is strained to its limits. As a result of this, fertile land becomes barren after a few years. The clearing of forests to set up industries results in the deficit and irregularity in the rainfall. The increasing industrialization depletes resources of fuel and increases pollution in air, water and land. Pollution is mainly responsible for disturbing the natural balance.
Conclusion
Our environment is where we live i.e. our sorroundings or whatever is around us. It includes everything on, in, and around the Earth-natural or made by humans and how each of these elements affect the others. It comprises the unique conditions on the Earth which allow life to exist and make it different from the other planets. Basically, environment refers to the interaction of humans and all other living forms with the physical aspects of the Earth.
The natural environment is the vast variety of landforms and life forms. The natural environment can be biotic or abiotic. Biotic components include all biological or living beings such as plants, animals, insects, etc.
On the other hand, abiotic components include all physical or non-living things such as land, minerals, soil, water and climate.
The human environment refers to anything that has been created by humans. So, buildings, mines, bridges, etc., and human activities like farming or manufacturing constitute human environment. All these modify the natural environment to create a new landscape.