Chapter 1

Introduction to Environment Studies

Definition: Environment
According to E. J. Ross "Environment is an external force which influences us."

Meaning of Environment
Environment, the surroundings or conditions in which a person, animal, or plant lives or
operates. The term environment is derived from a French word “Environia '' which means to
surround. It refers to both abiotic (physical or nonliving) and biotic (living) environments.

The components of Environment

1. Biotic Environment : It includes all biotic factors or living forms like plants, animals and
microorganisms.
2. Abiotic Environment : It includes non-living factors like temperature, light, rainfall, soil,
minerals etc. It comprises the atmosphere, lithosphere and hydrosphere.
3. Built Environment : It includes buildings, streets, houses, industries etc.

Multidisciplinary Nature of Environmental Studies

1. Biological sciences : It forms an important component of environmental sciences as it

is essential to acquire the knowledge of organisms living in it. The basic concepts of
botany, zoology, microbiology, biotechnology are studied for studying the different
aspects of environment and their inter relationships.
2. Physical sciences : It helps in understanding the changes which are involved with the
 abiotic system like the energy transfer and nutrients cycling, acid rain, ozone hole etc
3. Mathematics, statistics and computer sciences serve as an effective tool for
environment modeling.
4. Civil engineering, Chemical engineering and nanotechnology provide technical
solutions for environmental pollution control and water treatment.
5. Sociology, economics and management help in dealing with socio-economic aspects
of the environment.
6. Environment law provides legal measures for effective management and protection of
the environment.
7. Mass communication helps in spreading environmental awareness.

Scope and Importance of Environmental Studies

1. The study creates awareness among the people to know about various renewable and
nonrenewable resources of the region.
2. The endowment or potential, patterns of utilization and the balance of various resources
available for future use in the state of a country are analyzed in the study.
3. It provides knowledge about ecological systems and cause and effect relationships.
4. It provides necessary information about biodiversity richness and the potential dangers
to the species of plants, animals and microorganisms in the environment.
5. The study enables one to understand the causes and consequences due to natural
and main induced disasters (flood, earthquake, landslide, cyclones etc.,) and pollution
and measures to minimize the effects.
6. It enables one to evaluate alternative responses to environmental issues before deciding
an alternative course of action.
7. The study exposes the problems of overpopulation, health, hygiene, etc. and the role
of arts, science and technology in eliminating/ minimizing the evils from society.
8. The study tries to identify and develop appropriate and indigenous eco-friendly skills
and technologies to various environmental issues.
9. It teaches the citizens the need for sustainable utilization of resources as these
resources are inherited from our ancestors to the younger generation without
deteriorating their quality.
10. The study enables theoretical knowledge into practice and the multiple uses of the
environment.

Concept of Sustainability and Sustainable Development Meaning:

Sustainable Development
"Sustainable development is development that meets the needs of the present without
compromising the ability of future generations to meet their own needs."
The United Nations Conference on Environment and Development (UNCED) defines this using
the concept of sustainable development. "Sustainable development is development that meets
the needs of the present without compromising the ability of future generations to meet their
own needs”.
Sustainable Development Goals
1. End poverty in all forms everywhere
2. End hunger, achieve food security and improved nutrition and promote sustainable
agriculture.
3. Ensure healthy lives and promote well being for all ages
4. Ensure inclusive and equitable quality education and promote lifelong learning
opportunities for all
5. Achieve gender equality and empower all women and girls.
6. Ensure availability and sustainable management of water and sanitation for all.
7. Ensure access to affordable, reliable, sustainable and modern energy for all.
8. Promote sustained, inclusive and sustainable economic growth, full and productive
employment and decent work for all.
9. Build resilient infrastructure, promote inclusive and sustainable industrialization and
foster innovation.
10. Reduce inequality within and among countries.
11. Make cities and human settlements inclusive, safe, resilient and sustainable.
12. Ensure sustainable consumption and production patterns.
13. Take urgent action to combat climate change and its impacts.
14. Conserve and sustainably use the oceans, seas and marine resources for sustainable
development.
15. Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably
manage forests, combat desertification, and halt and reverse land degradation and halt
biodiversity loss.
16. Promote peaceful and inclusive societies for sustainable development, provide access to
justice for all and build effective, accountable and inclusive institutions at all levels.
17. Strengthen the means of implementation and revitalize the global partnership for
sustainable development.
In detail about Sustainable Development Goals

SDG 1: End Poverty

• The first of the 17 Sustainable Development Goals (SDGs) aims to end extreme poverty for
all people everywhere by 2030.
• Poverty is a multi-dimensional issue, and the goal is to create policies that address income
generation, access to basic services, and social protection.
• Sustainable Development Goals India is committed to reducing poverty by promoting
social and economic inclusion through various programs and schemes.

SDG 2: End Hunger

• The other SDGs aim to end hunger, achieve food security and promote sustainable
agriculture.
• Zero hunger includes increasing agricultural productivity, improving the resilience of food
systems, and ensuring access to nutritious and sufficient food for all.
• India plays a key role in achieving this goal by implementing policies and programs to
improve food security and agricultural sustainability.

SDG 3: Good Health and Quality of Life

• The goal of the 3rd SDG is to ensure healthy lives and promote well-being for all,
regardless of age.
• This includes reducing maternal and child mortality, fighting communicable and non-
communicable diseases and promoting mental health.
• India has made significant progress in improving healthcare access and outcomes,
contributing to the achievement of the Sustainable Development Goals 2030.

SDG 4: Quality Education

• The 4th SDG aims to provide inclusive and equitable quality education while promoting
lifelong learning opportunities for all.
• The Sustainable Development Goals focus on increasing access to quality education,
improving learning outcomes and reducing gender inequalities in educational opportunities.
• India has made great progress in this area through various policies and initiatives.

SDG 5: Gender Equality

• The 5th SDG aims to achieve gender parity and empower all women and girls.
• This SDG goal addresses various forms of discrimination, violence and harmful practices
against women, as well as promoting women’s participation in leadership roles and
decision-making.
 • India is working towards gender equality through various policies, laws and awareness
campaigns.

SDG 6: Clean Water and Sanitation

• The goal of the 6th SDG is to ensure access to and sustainable management of water and
sanitation for all.
• This includes improving water quality, increasing water use efficiency and protecting
water-related ecosystems.
• India has taken several initiatives to improve access to clean water and sanitation,
contributing to the UN Sustainable Development Goals.

SDG 7: Affordable and Clean Energy

• The 7th SDG is to ensure access to affordable, reliable, sustainable and modern energy for
all.
• These include increasing the share of renewable energy, improving energy efficiency, and
ensuring universal access to clean energy services.
• India has made significant progress in expanding its renewable energy potential and
promoting energy efficiency.

SDG 8: Decent Work and Economic Growth

• The goal of the 8th SDG is to promote sustained, inclusive and sustainable economic
growth, full and productive employment and decent work for all.
• This includes improving labor market conditions, supporting entrepreneurship and
promoting innovation.
• India has implemented various policies and programs to promote economic growth, create
jobs, and enhance workers’ rights.

SDG 9: Industry, Innovation and Infrastructure

• The 9th SDG focuses on building resilient infrastructure, promoting inclusive and
sustainable industrialization and fostering innovation.
• This includes increasing access to information and communication technologies, supporting
research and development, and promoting sustainable industrial practices.
• India is investing in infrastructure development and fostering a culture of innovation to
achieve this goal.

SDG 10: Reducing Inequality

• The 10th SDG aims to reduce inequality within and between countries by promoting social,
economic and political inclusion.
 • This includes ensuring equal opportunities, eliminating discriminatory policies, and
promoting global partnerships for development.
• India has been working to reduce income inequality and promote social inclusion through
various policies and programmes.

SDG 11: Sustainable Urban and Community Development

• The 11th SDG is to make cities and human settlements inclusive, safe, resilient and
sustainable.
• This includes ensuring access to affordable housing, improving urban planning and
enhancing the sustainability of cities.
• India has launched several initiatives to address the challenges of urbanization and promote
sustainable urban growth.

SDG 12: Consume and Produce Responsibly

• The 12th SDG aims to ensure sustainable consumption and production patterns by
promoting resource efficiency, reducing waste and encouraging sustainable business
practices.
• India is working to implement sustainable production and consumption practices through
various policies, regulations and awareness campaigns.

SDG 13: Climate Action

• The 13th SDG focuses on taking urgent action to tackle climate change and its impacts by
reducing greenhouse gas emissions, enhancing climate resilience and supporting climate
adaptation efforts.
• India has been actively involved in international climate talks and has implemented various
domestic initiatives to combat climate change.

SDG 14: Life Below Water

• The goal of the 14th SDG is to conserve and sustainably utilize the oceans, seas and marine
resources for sustainable development.
• This includes stopping marine pollution, protecting marine ecosystems, and ensuring
sustainable fisheries.
• India is working to protect its marine resources and ecosystems through various
conservation and sustainable management initiatives.

SDG 15: Life on Land

• The 15th SDG promotes the protection, restoration and sustainable use of terrestrial
ecosystems, halting biodiversity loss, and combating desertification.
 • India has made significant efforts in promoting forest conservation, wildlife conservation
and sustainable land management practices.

SDG 16: Institute for Peace and Justice

• The 16th SDG is to foster peaceful and inclusive societies, provide access to justice for all,
and build effective, accountable and inclusive institutions.
• India is working towards ensuring the rule of law in its institutions, reducing corruption and
increasing transparency and accountability.

SDG 17: Partnership to Achieve the Goals

• The 17th SDG stresses the importance of global partnerships to support and achieve the
Sustainable Development Goals.
• This includes enhancing international cooperation, promoting sustainable development
investment, and fostering multi-stakeholder partnerships.
• India is actively engaged in international partnerships and cooperation to achieve the 17
Sustainable Development Goals.

Chapter 2
Ecosystem

Meaning: Ecosystem
An ecosystem is a dynamic entity composed of a biological community and its associated
abiotic environment Often the dynamic interactions that occur within an ecosystem are
numerous and complex

Meaning: Ecology
Ecology (from Greek: olkoç, "house", or "environment": λoyla, "study of") is the branch of biology
which studies the interactions among organisms and their environment. Objects of study include
interactions of organisms with each other and with abiotic components of their environment.

Structure and Function of an Ecosystem or Components of an Ecosystem

Each Ecosystem has two main Components:
1. Abiotic
2. Biotic
 1.Abiotic Components:
The abiotic components of an ecosystem are all of the nonliving elements. They include
the water, the air, the temperature and the rocks and minerals that make up the soil.

Abiotic components are mainly of two types:

a. Climatic Factors: Which include rain, temperature, light, wind, humidity etc.
b. Edaphic Factors: Which include soil, pH, topography minerals etc.
The functions of important factors in abiotic components are given below:
a. Soil is much more complex than simple sediments. They contain a mixture of weathered
rock fragments, highly altered soil mineral particles, organic matter, and living
organisms. Soils provide nutrients, water, a home, and a structural growing medium for
organisms. The vegetation found growing on top of a soil is closely linked to this
component of an ecosystem through nutrient cycling.
b. The atmosphere provides organisms found within ecosystems with carbon dioxide for
photosynthesis and oxygen for respiration. The processes of evaporation, transpiration
and precipitation cycle water between the atmosphere and the Earth's surface.
c. Water is the medium by which mineral nutrients enter and are translocated in plants. It is
also necessary for the maintenance of leaf turgidity and is required for photosynthetic
chemical reactions. Plants and animals receive their water from the Earth's surface and
soil. The original source of this water is precipitation from the atmosphere.

2. Biotic Components:
The living organisms including plants, animals and micro-organisms (Bacteria and Fungi) that
are present in an ecosystem form the biotic components. The biotic components of the
ecosystem both live on and interact with the abiotic components.
On the basis of their role in the ecosystem the biotic components can be classified into three
main groups:
a. Producers:
i. Producers are the living organisms in the ecosystem that take in energy from sunlight
and use it to transform carbon dioxide and oxygen into sugars.
ii. Plants, algae and photosynthetic bacteria are all examples of producers. As the green
plants manufacture their own food they are known as Autotrophs (ie. auto= self, trophos
feeder). Producers form the base of the food web and are generally the largest group in
the ecosystem by weight, or biomass.
iii. They also act as an interface with the abiotic components of the ecosystem during
nutrient cycles as they incorporate inorganic carbon and nitrogen from the atmosphere.
iv. The chemical energy stored by the producers is utilized partly by the producers for
their own growth and survival and the remaining is stored in the plant parts for their
future use.
b. Consumers:
i. Consumers are living organisms in the ecosystem that get their energy from
consuming other organisms. Conceptually, consumers are further subdivided by what
they eat.
ii. Herbivores eat producers, carnivores eat other animals and omnivores eat both. Along
with producers and decomposers, consumers are part of what is known as food chains
and webs, where energy and nutrient transfer can be mapped out.
iii. Consumers can only harvest about 10 percent of the energy contained in what they
eat, so there tends to be less biomass at each stage as you move up the food chain.

The consumers are of four types

a. Primary Consumers or First Order Consumers or Herbivores:
These are the animals which feed on plants or the producers. They are called
herbivores. Examples are rabbits, deer, goats, cattle etc.
b. Secondary Consumers or Second Order Consumers or Primary Carnivores
The animals which feed on the herbivores are called the primary carnivores. Examples
are cats, foxes, snakes etc.
c. Tertiary Consumers or Third Order Consumers:
These are the large carnivores which feed on the secondary consumers.
Examples are Wolves.
d. Quaternary Consumers or Fourth Order Consumers.
These are the largest carnivores which feed on the tertiary consumers and are not eaten
up by any other animal. Examples are lions and tigers, and hawks.
Note: The examples may very based on type of food chain and food web.

c. Decomposers or Reducers:
i. Decomposers are the living component of the ecosystem that breaks down waste material and
dead organisms. Examples of decomposers include earthworms, dung beetles and many
species of fungi and bacteria.
ii. The decomposers are known as Saprotrophs (ie., sapros = rotten, trophos = feeder).
Ill. They perform a vital recycling function, returning nutrients incorporated into dead organisms
to the soil where plants can take them up again.
iv. In this process, they also harvest the last of the sunlight energy initially absorbed by
producers. Decomposers represent the final step in many of the cyclical ecosystem processes.
Meaning: Food Chain
A food chain is a linear network of links in a food web starting from producer organisms (such as
grass or trees which use radiation from the Sun to make their food) and ending at apex predator
species (like grizzly bears or killer whales), detritivores (like earthworms or woodlice), or
decomposer species (such as fungi or bacteria).
Definition: Food chain
A food chain may be defined as the transfer of energy and nutrients through a succession of
organisms through repeated processes of eating and being eaten.

Food chains are of three types:

1. Grazing food chain
2. Parasitic food chain
3. Saprophytic or detritus food chain

1. Grazing food chain

The grazing food chain starts from green plants and from autotrophs it goes to
herbivores (primary consumers) to primary carnivores (secondary consumers) and then
to secondary carnivores (tertiary consumers) and so on. The gross production of a green
plant in an ecosystem may meet three fates-it may be oxidized in respiration, it may be
eaten by herbivorous animals and after the death and decay of producers it may be
utilized by decomposers and converters and finally released into the environment. In
herbivores the assimilated food can be stored as carbohydrates, proteins and fats, and
transformed into much more complex organic molecules.
 Ex: Grass-rabbit- fox- tiger
2. Parasitic food chain:It goes from large organisms to smaller ones without outright killing
as in the case of predators.
Ex: Trees →→ Fruit eating birds-> Bugs
3. Detritus food chain:
The dead organic remains including metabolic wastes and exudates derived from
grazing food chains are generally termed detritus. The energy contained in detritus is not
lost in the ecosystem as a whole, rather it serves as a source of energy for a group of
organisms called detritivores that are separate from the grazing food chain. The food
chain formed is called detritus food chain.
Ex: Dead organic matter→ Detritivores

Food Web Meaning:

Food Web
Food web is an important conceptual tool for illustrating the feeding relationships among
species within community, revealing species interactions and community structure, and
understanding the dynamics of energy transfer in an ecosystem.
Ecological Pyramid Meaning:
Ecological Pyramid
An ecological pyramid (also trophic pyramid, eltonian pyramid, energy pyramid, or sometimes
food pyramid) is a graphical representation designed to show the biomass or bio productivity at
each trophic level in a given ecosystem)

Types of Ecological Pyramid

1. Pyramid of numbers
This shows the number of organisms in each trophic level without any consideration for
their size.

2. Pyramid of biomass
This indicates the total mass of organisms at each trophic level. Usually, this type of
pyramid is larger at the bottom and gets smaller going up, but exceptions do exist.
 3. Pyramid of Energy
When production is considered in terms of energy, the pyramid indicates not only the
amount of energy flow at each level, but more importantly, the actual role the various
organisms play is the transfer of energy.

Meaning: Ecological Succession

Ecological succession is the process of change in the species structure of an ecological
community over time. The time scale can be decades (for example, after a wildfire), or even
millions of years after a mass extinction
● In primary succession, newly exposed or newly formed rock is colonized by living things
for the first time.
● In secondary succession, an area that was previously occupied by living things is
disturbed then re-colonized following the disturbance.
● In ecology, climax community, or climatic climax community, is a historic term for a
biological community of plants, animals, and fungi which, through the process of
ecological succession and the development of vegetation in an area over time, have
reached a steady state.
Types of Ecosystem

Meaning: Forest Ecosystem

A forest ecosystem is a natural woodland unit consisting of all plants, animals and
microorganisms (Biotic components) in that area functioning together with all of the non-living
physical (abiotic) factors of the environment.
Example: Deciduous forests

Types of forest in India

1. Moist tropical Forest
Where the amounts of annual rainfall ranges between 200 and 250 cm, the mean annual
temperature lies between 24°c and 27°c and humidity percentage is 80, the evergreen
forests degenerate into semi evergreen forests; such forests are found along the
Western Coast, in Upper Assam, lower slopes of the eastern Himalaya, Orissa coast
and neighboring hills. Important plant varieties include bamboos, epiphytes, Aini, Semul,
Gutel, mundane, Hopea Benteak, Kadam Irul, rosewood, Haldu, Kanju, Bijasal, Kusum,
Bomsum, Indian chestnut Litsea, Holloch, Champa and Mesua etc.
2. Dry tropical Forest
These types of forests are mainly found in Indian Northern Hilly regions and some states
of Southern India. Basically, these forests are generated where average annual rainfall
ranges from Ecosystem 51 cm to 151 cm. Trees of these forests drop its leaves in winter
(when the weather remains driest) and new leaves are generated after winter. During the
rainy season these types of forest completely decorate lush green leaves. Some
significant trees of dry Tropical Forest are Sal Acacia, Mangoes and Bamboo.
3. Montane temperate Forest
These types of forests are mainly generated in Northern middle Himalayas ranges (1801
to 3001 Meters) and Southern Nilgiri higher Mountain ranges. It takes about 201 cin
average annual rainfalls to produce these types of forests. Some significant trees of
Montane temperate Forest are Rhododendrons, Ferns, Oak, Maple. Juniper, Deodar,
Chilgoza, etc.
4. Montane subtropical Forest
These types of forests mainly generated in the state of Assam, Nagaland, Mizoram,
Meghalaya, Manipur, Arunachal Pradesh, etc. mountain ranges of Western Ghats are
 also the abode of these types' forests. Some significant trees of Montane subtropical
Forest are Poonspar, cinnamon, rhododendron, Sal, Sandan, Laburnum, pomegranate,
olive, oleander, etc.
5. Alpine Forest
These grasslands start at an elevation of above 3000m and grow up to the region just
below the snowline. They are common in both the main Himalayan regions as well as
the barren cold deserts of the Tran Himalaya. Low alpine grasslands are common with
the vegetation not growing higher than 1.5m. Climatic conditions vary from the sub-arctic
to arctic, with snow covering the ground for over 5 months a year. The growing season
for the plants is thus stunted. Pastures are grazed by migratory cattle in summer. The
vegetation consists mainly of the black juniper, the drooping juniper common trees.
6. SubAlpine Forest
These forests are found between 2901 and 3501 meters, near the snow line all over the
Himalayas and the dry cold deserts. Average temperatures in summers range from 20°C
to 22°C. Winter temperatures are usually below the freezing point accompanied by lots
of snow. Major common trees of this type of forest are Juniper, Rhododendron, Willow
and Black Currant. In the eastern parts, Red Fir, Black Juniper, Birch and Larch are the
common trees.

Meaning: Grassland ecosystem

A biological community that contains few trees or shrubs, is characterized by mixed herbaceous
(nonwoody) vegetation cover, and is dominated by grasses or grasslike plants.
Example: Savanna, Shivalik Hills

Meaning: Desert ecosystem

Desert ecology is the study of interactions between both biotic and abiotic components of desert
environment A desert ecosystem is defined by interactions between organism populations, the
climate in which they and any other non-living influences on the habitat.
Example:Gobi, Great Basin, and Namib Deserts. Antarctica is a desert, but there are no
camels and sand dunes

Meaning: Aquatic ecosystem

An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are
dependent on each other and on their environment live in aquatic ecosystems. The two main
types of aquatic ecosystems are marine ecosystems and freshwater ecosystems
Examples: Ponds, streams, lakes, rivers, oceans, estuaries.

Pond Ecosystem
A pond is self-sufficient and an ideal example of the ecosystem. In a pond, the intimate
relation between the inhabiting living and nonliving components is well understood. The non-
living objectives are various types of organic and inorganic substances such as water, sun rays,
CO,. oxygen, calcium phosphorus etc. The living components are producers, primary
consumers, secondary consumers, tertiary consumers and various types of decomposers
1. Producers: Various types of photosynthetic algae and shallow water plants living in the
pond and the producers. The floating organisms are called plankton. The minute plants
of plankton type are known as phytoplankton. Green aquatic algae and other aquatic
plants can live by producing food the process of the photosynthesis, so they are called
 producers
2. Primary consumers: These are various types of floating minute insects, larvae of
mosquito and other by microscopic animals like zooplankton etc. Floating minute
animals are called zooplankton. These consumers cannot manufacture their own food
and they live on by eating the producers directly.
3. Secondary consumers: Small fishes, some aquatic insects, prawns, frogs etc. are
secondary consumers They can neither manufacture their own food nor accept the
producers as food. They live on by eating the primary consumers.
4. Tertiary consumers: Small fishes, prawn and all other animals that feed upon the
secondary consumers are known as tertiary consumers. Large fishes like shoal, stork
and heron are the tertiary or highest consumers,
5. Decomposer: In pond water, various types of fungi and bacteria live as saprophytes
which are known as a decomposer. These decomposers can live by floating on water or
live at the bottom of clay. They attack living or dead consumers and help to rot. As a
result, organic and inorganic chemical substances usable by the producers have formed
again. The producer community of the pond uses these decomposed elements. The
flowchart gives an idea about the components of the pond ecosystem.
Marine Ecosystem
A marine ecosystem is any that occurs in or near salt water, which means that marine
ecosystems can be found all over the world, from a sandy beach to the deepest parts of the
ocean. An example of a marine ecosystem is a coral reef, with its associated marine life-
including fish and sea turtles - and the rocks and sand found in the area.
1. Estuary: An estuary is a partly enclosed coastal body of water with one or more rivers or
streams flowing into it, and with a free connection to the open sea. (Ex: Thane creek)
2. Wetland: is a zone of flat lands that has groundwater of shallow depth and that ascend
to the surface in determined periods, forming lagoons and marshes, until where they
come to live hundreds of species. There are five classes of wetlands: marine, estuarine,
lake, riparian and marshy:(Ex: Chilika lake)
3. Mangrove: is a grouping of semi-submerged trees that have been flooded with water,
with high levels of salinity and therefore they develop and survive in coastal lands. The
trees grow on long roots, which like stilts raise the trunks above the level of the
waters.(Ex: Sunderbans)
4. Coral reef: it is one of the richest aquatic ecosystems of the planet, product of the great
amount of species that inhabit them (fish, snails, corals and algae). (Ex: Andaman and
Nicobar Island.