BGGCT- 135: Environmental Geography

BLOCK 1 INTRODUCTION TO ENVIRONMENTAL 7

GEOGRAPHY
Unit 1 Concepts and Scope of Environmental Geography 9
Unit 2 Ecology and Ecosystems 17
Unit 3 Biogeography 32
BLOCK 2 HUMAN-ENVIRONMENT RELATIONSHIP 55
Unit 4 Equatorial Regions 57
Unit 5 Desert Regions 69
Unit 6 Mountainous Regions 86
Unit 7 Coastal Regions 103
BLOCK 3 ENVIRONMENTAL PROBLEMS AND 121
MANAGEMENT
Unit 8 Understanding Pollution 125
Unit 9 Air Pollution 139
Unit 10 Solid and Liquid Waste 153
Unit 11 Biodiversity Loss 167
BLOCK 4 CONSERVATION OF ENVIRONMENT 185
Unit 12 Environmental Conservation and Management 189
Unit 13 Environmental Impact Assessment-Methods and 199
Techniques
Unit 14 Environmental Standards and Monitoring 215
BLOCK 5 ENVIRONMENTAL ISSUES, PROGRAMMES AND 237
POLICIES
Unit 15 Environmental Issues 241
Unit 16 United Nations and the Environment 259
Unit 17 Environmental Policies with Special Reference 269
to India
 ENVIRONMENTAL GEOGRAPHY- INTRODUCTION
(BGGCT-135)
The subject of environmental geography mainly deals with the natural
environment and the human-nature interrelationship. To serve the
undergraduate learners, this course is set out in the form of different blocks,
such as introduction to environmental geography, human-environment
relationship, environmental problems and management, conservation of
environment and environmental issues, programmes and policies.
Our planet Earth supports various ecological communities of plants and
animals which live together in different geographical regions. The distribution
of living organisms may not be uniform because of varying climatic conditions
on the Earth. Studying an ecosystem is important to understand the
relationships between organisms with their biotic and abiotic environments on
the Earth. Block 1 introduces you to environmental geography, dealing with
the basic concepts and importance of the environment, ecology and
ecosystems, and biogeography spread over three units. The interaction
between human beings and their environment is such that the environment
influences humans and, at the same time, human beings also get influenced
by the environment. You will study the human-environment relationship in four
distinct geographical regions, namely the equatorial, desert, mountainous,
and coast in Block 2.
Pollution is a major concern all over the globe. Air, water, soil, and noise
pollution have increased tremendously in recent times. Due to increased
levels of pollutants in the environment, human beings are not able to get fresh
breathable air, clean potable water and fresh food. It is not only limited to
humans, all other living organisms are also facing severe problems. We have
introduced a dedicated Block 3 on environmental problems and management
dealing with the basics of pollution, air pollution, solid and liquid waste, and
biodiversity loss.
The sustainable development and conservation of the environment are
necessary for the survival and well-being of the present and future
generations. To understand the state of our environment, we need to monitor
the environment cautiously through various measures like environmental
impact assessment and the setting up of environmental standards. So that it
can help in understanding the standards, norms, and regulations that form the
basis for the achievement of the goals of sustainable development. It will also
help you to understand the environmental standards in relation to various
environmental parameters and their implications for the environment.
Block 4 of this course describes and explains various aspects of the
environment, namely conservation and management of the environment,
environmental impact assessment, environmental standards and monitoring.
Issues like climate change, global warming, pollution, and forest fires, etc. are
directly or indirectly increasing the risk of human health as well as other life
forms on the globe. The United Nations and other nations are involved in
formulating rules and regulations for environmental management at regional
as well as local levels. Environmental programmes and policies may differ
from one country to another. In India, several laws have been enacted to
protect the air, water, soil, forest, and other resources of the environment
since independence. An attempt has been made to identify the significant
environmental adverse effects caused by human activities and it is essential
to eliminate these consequences through proper management policies and
legislation from a global to a local perspective. In three units, the final Block 5
introduces you to environmental issues, programs, and policies dealing with
climate change, global warming, pollution, and health, United Nations
programs, and Indian environmental laws. Overall, this course will provide an
opportunity to think various environmental problems in a wider context.
We hope that after studying this course on Environmental Geography, you will
be able to understand the subject of environmental geography in terms of
ecology and ecosystems, biogeography, human-environmental relationship,
environmental problems, methods and policies for conserving and managing
the environment for better maintenance of our planet Earth.
Our best wishes are always with you in this endeavor.
We suggest for any assistance regarding this course, you can contact at:
knrao@ignou.ac.in and subhakanta@ignou.ac.in
BLOCK

1
INTRODUCTION TO ENVIRONMENTAL
GEOGRAPHY
UNIT 1
CONCEPTS AND SCOPE OF
ENVIRONMENTAL GEOGRAPHY 9
UNIT 2
ECOLOGY AND ECOSYSTEMS 17
UNIT 3
BIOGEOGRAPHY 32
GLOSSARY 54
BLOCK 1: INTRODUCTION TO ENVIRONMENTAL
GEOGRAPHY
Environmental geography explores the natural environment and human-
nature interrelationship spatially in a scientific way, which is considered to be
one of the important subject of interdisciplinary studies. Understanding the
relationships between organisms with their biotic and abiotic environments on
the Earth is one of the pivotal responsibilities of human beings. Environment
and the living organisms are two dynamic and complex components of nature.
Environment can influences the life of organisms including hamans, plants,
animals etc. Human ecology explains that how humans have developed
different forms of subsistence technologies for controlling environmental
resources towards their food security and wellbeing since the very beginning
of human evolution.

The geological and climatic processes are largely affected the life of
organisms in several ways that can be understood through historical
biogeography. On the other hand, the ecological biogeography mainly deals
with organisms’ response to their surroundings. Human beings explored the
land extensively for observing organism’s association with their natural
environment that helped now to understand the complexities of natural
phenomena. Interestingly, the distribution of organisms on the planet Earth is
not uniform and is primarily influenced by the climatic conditions. Therefore, a
distinct ecological community of plants and animals can be seen living
together in particular geographical regions of the world.

This block is spread into three units dealing with the basic concepts and
importance of the environment, ecology and ecosystems, and biogeography.

Unit 1: Concepts and Scope of Environmental Geography

This unit introduces the environment and its types, and the role of
geographers in environmental studies. Environmental geography not only
explains the physical and social environment but also highlights the need of
environmental studies in the geographic perspective.

Unit 2: Ecology and Ecosystems

We see several natural and human made features in our day to day life.
These are arranged and interlinked in a particular way for their sustenance.
To relate these interrelationships between organisms and the environment,
we have introduced the theme of ecology, the concept and structure of
ecosystem, and human ecology.

Unit 3: Biogeography

This unit introduces biogeography. We have explained the concept, scope,

and classification of biogeography. You will also study various
biogeographical regions or biomes of the world.

We hope after studying this block, you will better understand the basic
concepts and scope of environmental geography, ecology and ecosystems
along with biogeography. Our best wishes are with you in this endeavour.
 Concepts And

1
Scope of
Environmental
UNIT Geography

CONCEPTS AND SCOPE OF

ENVIRONMENTAL
GEOGRAPHY

Structure
1.1 Introduction 1.4 Role of Geographers in
Expected Learning Outcomes Environmental Studies
1.2 Meaning and Concept of 1.5 Summary
Environmental Geography 1.6 Terminal Questions
1.3 Types of Environment 1.7 Answers
Physical Environment 1.8 References and Further
Social Environment Reading

1.1 INTRODUCTION
Geography has been derived from two Greek words ‘Geo’ means Earth and
‘Graphy’ means Description which implies description of the ‘Earth’. It is
indeed a discipline that describes the Earth’s surface, its physical features as
well as the human and their cultural features along with the spatial distribution
of both the features. With the growth and development of human civilisation
and advent of science, geography has been considered as a scientific
interpretation of areal differentiation in the ‘human-environment relationship’.
Since beginning of the subject, geography as the study of the Earth’s surface
has focused on the natural environment on one hand and the human made
cultural environment on the other. Peter Hagget (1977) in his book on
“Geography- A Modern Synthesis” emphasised that “geography is concerned
with two major interacting systems i.e. the ecological systems (Ecosystem)
that links man with his environment and the other one is the ‘Spatial System’
that links one region of the Earth with another”. Savindra Singh in his book
“Environmental Geography” mentioned that it is the study of the inter-
relationship between the living organisms and its natural environment as well
9
Introduction to as the relationship between technologically advanced “economic man and his
Environmental
natural environment” in the present context. Since 1970, the geography
Geography
departments of most of the universities have included environmental studies
in their under graduate and post graduate level programs as ‘Environmental
Geography’.

In this Unit, you will study the subject of environmental geography, types of
environment and the geographer’s role in environmental studies. Section 1.2
explains you about meaning and the concept of environmental geography
followed by various types of environment including physical and social in
Section 1.3. You will also study the role of geographers in environmental
studies in Section 1.4.

Expected Learning Outcomes

After completing the study of this unit, you should be able to:
v explain the concept and scope of environmental geography;
v describe the types of environment; and
v ascertain the role of geographers in environmental studies.

1.2 MEANING AND CONCEPT OF

ENVIRONMENTAL GEOGRAPHY
Geography has inherited the concept of environmentalism from Greek
philosophers that environment determines the man and his activities.
Subsequently environmental focus in geography appeared in the nineteenth
century significant contributions of German geographers. Alexander Von
Humboldt, the founder of modern geography demonstrated the man’s
dependence on his environment by putting forward the doctrine of
environmental determinism emphasising the role of environment on the type
of life in a geographic location. Carl Ritter, a German geographer also
propounded the influence of environmental factors on human activities and
even on human behaviour as described in his book ‘Erkunde’. Fredric Ratzel
in his classical literature ‘Anthropogeography’ illustrated his thoughts on
environmental impact on man. Gradually with the advent of science and
technology and emergence of environmental issues and challenges across
the globe, the environmental focus in geography has shifted to a branch of
knowledge within the subject shown as ‘Environmental Geography’. A. N.
Strahler (1977) has discussed the geographical aspects and its relationship
with environment in his book “Geography and Man’s Environment”
focussing on the theme that man and land convey the essence of geography.

Now, we can understand that the environmental geography is the branch

of geography that describes the spatial aspects of interactions between
humans and the natural world. It is the study of systematic description of
different components of environment and interactions of human with these
components and their spatial variation over the Earth’s surface. It is
multidisciplinary in nature and is related to other disciplines like life sciences,
physical sciences, ecological sciences, chemical sciences and humanities like
economics, sociology and public administration etc. It is concerned with the
10
spatial attributes of all the phenomena related to the environment. It studies Concepts And
Scope of
the various biomes and human influence, patterns of biodiversity at the global,
Environmental
national and local level, studies the spatial pattern of physical and Geography
anthropogenic degradation of environment. Various environmental issues and
problems like global warming, climate change, natural hazards and disaster
management, loss of biodiversity and environmental degradation and its
variation across the globe are also the major thrust areas of environmental
geography. Environmental conservation, management and sustainable
development are also an integral part of the scope of environmental
geography.

Variations in the ways how people inhabit and use environments in places,
and the processes (natural and social) that operate at different scales to alter
those environments and the lives of people relying on them, are strong focus
areas of environmental geography. Environmental geography uses a critically
important set of spatial and analytical tools for assessing the impact of human
presence in the environment by measuring the result of human activity on
natural systems. By its very nature, environmental geography is a discipline
that seeks to integrate and synthesize knowledge of man-environment
relationship in a spatial frame. Thus, the scope of environmental geography
revolves around the study of the biotic and abiotic components of
environment and their spatial interrelationship encompassing the four vital
spheres of the Earth i.e. lithosphere, atmosphere, biosphere and
hydrosphere. Given the scope and contents of the subject, environmental
geography can prepare students for careers in environmental planning and
conservation, environmental assessment and monitoring, resource
management, environmental hazards and their management and
environmental education etc. Students studying this programme will develop
competencies in a broad interdisciplinary areas of the natural and social
sciences, as well as complementary spatial and analytical techniques.

SAQ 1
Define environmental geography.

1.3 TYPES OF ENVIRONMENT

You have understood the scope and importance of the subject environmental
geography. Let us now study the broad components of environment.
Environmental geography is primarily centered around three focus areas in its
study. These are:

1) environment,
2) human, and
3) human and environment interactions.
In its broadest sense, environment refers to our immediate surroundings in
which all living and non-living components co-exist. It includes both the biotic
and abiotic components around us. We live in an environment which is natural
as well as human-made. These are the surrounding conditions in which
humans, animals and plants live. Every individual living in environment has an 11
Introduction to impact on it whereas the environment also influences an individual’s
Environmental
behaviour and spatial activities. Environment and the organisms are two
Geography
dynamic and complex components of the nature. Environment largely
regulates the life of the organisms including human beings.

Environment is the sum of conditions that surrounds us at a given point of

time and space. It is comprised of the interacting systems of physical,
biological and cultural elements which are interlinked both individually and
collectively. It is also the conditions in which an organism has to survive or
maintain its life process. It influences the growth and development of living
forms. It consists of atmosphere, hydrosphere, lithosphere and biosphere.
The chief components of environment are soil, water, air, organisms and solar
energy. It has provided us all the resources for leading a comfortable life.
Thus, it can be stated that individuals and environment are interrelated and
complementary to each other. The environment can be broadly classified into
two major categories such as natural or physical environment and human-
made social environment. You need to study the following sub-sections to
understand about these two types of environments in detail.

1.3.1 Physical Environment

Physical environment is the terrestrial environment which is a creation of
complex natural environmental conditions. Earth’s surface features such as
rivers, mountains, deserts, land, water, oceans, volcanoes and atmosphere
are the examples of physical environment. Although, all these grew or
developed independent of humankind, it is the outcome of direct interactions
of human, society and nature. Therefore, the examples of physical
environment includes all living and non-living things occurring naturally on the
Earth. It is often used as a synonym for natural environment. Geography of
environment is also called as the physical environment of human. Physical
environment comprises of the study of the atmosphere, lithosphere,
hydrosphere and biosphere. Fig.1.1 shows three different kinds of natural
environment comprising mainly of land, oceanic waters, and clouds.

Fig. 1.1: Representation of physical environment: land, water and atmosphere.

The ‘natural environment’ as it consists of things that are provided by nature.

12 Simultaneously, it can also be called ‘physical environment’ as it includes the
physical conditions for the evolution and substance of life. The geographic or Concepts And
Scope of
physical conditions exist independently of human’s existence. Human has
Environmental
limited and often no control over them. This environment includes; the surface Geography
of the earth, natural resources, land and water, mountains and plains, fertile
lands and deserts, oceans, weather and climatic factors, seasons, storms and
cyclones, etc. It also includes biological conditions such as plants, animals
together with all their complexities.

1.3.2 Social Environment

You must be aware that human being cannot directly live in the natural
physical environment. To adjust with the prevailing environmental conditions,
the human beings always try to create some kind of mechanisms for
suitables adjusting with their surrounding environmental conditions. The
adjustment means the process of adaptation according to the prevailing
environmental conditions. This can be altogether called human-made
environment, a human creation. This human-made environment is also
known as social environment. It refers to the immediate social settings in
which people live. Social environment includes culture, language, social
conditions, health, living conditions, and economic capability of the people
living in an area. In order to control the conditions of his life and have a good
living, human has created a new environment which can be called ‘as
human-made environment’ and some have named it ‘social-cultural
environment’. It can be sub-divided into two types: (a) outer environment and
(b) inner environment. Let us now understand what actually are these.

Fig. 1.2: Human-made environment representing range of spatial human

activities in physical environment.

a) The Outer Environment

Outer environment is the part of physical environment that human has created
on her/his own with the help of evolving technology. It is the modification of
physical environment that has helped to cope up with the progress of
humankind and the development of environment. Human while making a
living on the surface of Earth has modified the physical environment through 13
Introduction to the use of science and technology. It can be understood as ‘outer
Environmental
environment’. Whatever we are today, is a result of the modifications of
Geography
physical environment introduced by human’s technology, knowledge and
capital. It includes our houses and cities, our means of transport and
communication, our comforts and conveniences. It also includes the vast
systems of industry and machinery created by the humans. It covers, in brief,
the whole apparatus of our civilization.

b) The Inner Environment

Inner environment is the part of social environment that embraces or endures

as long as the society cherishes. It has a profound impact on the human
lives. It is often called social heritage as it is an important factor for
humankind to exist, live and progress. Our inner environment is the society
and its socio-cultural norms and traits along with itself. It is the social envi-
ronment created by human. It consists of the organizations, social regulations
and the traditions. It includes the religious traditions and customs which every
human group has created for their own living. It should be noted that human
cannot separate the outer environment from the social environment. The
outer and the inner environments are blended together in the social
environment of human. For example, the land which we bring under
cultivation is more than a land; it is a form of property. It is often worshipped
also, as the Hindus do. The houses are also homes that represent the
institution of family. Thus, the various attributes of total environment (the
physical, the inner and the outer) are merged together in our experience that
manifests the social environment in an opt manner.

SAQ 2
Choose the following statements as True or False.

a) Environmental geography deals with the spatial variations in the human

environment relationship over the Earth’s surface.
b) Volcanic activity is influenced by human activities.
c) The environment which has been modified by human activities is a part
of social environment.
d) Rivers and mountains are not a part of the physical environment of the
Earth.
e) Religious beliefs and faiths are not a part of the social environment.

1.4 ROLE OF GEOGRAPHERS IN

ENVIRONMENTAL STUDIES
You now know the types of environment including physical and social
environment. It is essential to know the role of geographers in studying the
environment. Environmental geographers are not only familiar with how
natural systems function, but they also know that humans amongst all the
organism are the most dominant agent of change in nature. They realize that
it is not possible to understand environmental problems without understanding
the physical processes as well as the demographic, cultural, and economic
14
processes that lead to increased resource consumption and waste. Concepts And
Scope of
Environmental geographers or makeout along a variety of academic paths,
Environmental
which was cross, mingle, or converge with those of other disciplines. By its Geography
very nature, geography is a discipline that seeks to integrate and synthesize
both the converging and diverging domains of academic knowledge. Therein
lays its strength. For geographers, the Earth is the home of humans.
Environmental study is an inter-disciplinary area of knowledge cutting across
various disciplines of sciences and humanities as well. Geographer’s study of
areal differentiation of the Earth’s surface as a science of integration and
synthesis is well equipped to contribute towards environmental studies using
their spatial analytical tools. Thus, geographers have a very significant role in
studying, analysing and synthesising the spatial variations in human-
environment relationship which is the prime goal of environmental geography.

SAQ 3
Explain the role of geographers in environmental studies.

1.5 SUMMARY
In this unit, you have studied:

· The meaning and scope of environmental geography.

· How environmental geography has emerged as an independent
branch of knowledge within geography and its significance in
understanding the human-environment relationships across the globe.
· The two significant branches of environment are i.e. physical
environment and social environment. This unit has also attempted to
explain two different types of social environment i.e. outer and inner
environment.
· You have also studied the components of all these varied environment
types with suitable examples.
· The role of geographers in environmental studies.

1.6 TERMINAL QUESTIONS

1. Discuss the scope of environmental geography.
2. Explain the characteristics of physical environment.
3. Describe how the social environment is affecting the day to day life of
human beings.

1.7 ANSWERS
Short Answer Questions
1. Environmental geography is the branch of geography that describes the
spatial aspects of interactions between humans and the natural world. It
15
Introduction to is the study of systematic description of different components of
Environmental
environment and interactions of human with these components and their
Geography
spatial variations over the Earth’s surface.

2. a) True; b) False; c) True; d) False, e) False

3. Geographers study natural systems functions, processes and their

interactions with humans. They understand environmental problems by
studying various physical processes of the Earth and cultural processes
of human simultaneously.

Terminal Questions
1. Scope of environmental geography revolves around the study of the biotic
and abiotic components of the environment and their spatial
interrelationships encompassing the four vital spheres of the Earth i.e.
atmosphere, lithosphere, biosphere and hydrosphere. Refer to the
Section 1.1.

2. Physical environment is the terrestrial environment which is a creation of

complex natural environmental conditions. For detailed description, you
may refer to the Sub-Section 1.3.1.

3. Social environment refers to the immediate social settings in which

people live. Social environment includes culture, language, social
conditions, health, living conditions, and economic capability of the
people living in an area. Refer to the Sub-Section 1.3.2.

1.8 REFERENCES AND FURTHER READING

1. Castree, N., Demeritt, D., Liverman, D. and Rhoads, B (Ed). (2009). A
Companion to Environmental Geography. London: Blackwell Publishing
Ltd.

2. Hussain, M. (2002). Human Geography. New Delhi: Rawat Publications.

3. Rana, S.V.S. (2009). Essentials of Ecology and Environmental Science.

New Delhi: Prentice Hall India Learning Private Limited.

4. Saxena, H. M. (2017). Environmental Geography. New Delhi: Rawat

Publications.

5. Singh, S. (2008). Environmental Geography. Allahabad: Prayag Pustak

Bhawan.

6. http://www.nec.com/en/global/eco/

7. http://www.environment-agency.gov.uk/

16
 Ecology and

2
Ecosystems

UNIT

ECOLOGY AND ECOSYSTEMS

Structure
2.1 Introduction Horticultural Societies
Expected Learning Outcomes Humans as Herders
2.2 Ecology Humans as Cultivators
2.3 Ecosystem Humans in Modern Industrial
Concept of Ecosystem and Urban Societies
Ecosystem Structure 2.5 Summary
Ecological Processes 2.6 Terminal Questions
Ecological Communities 2.7 Answers
2.4 Human Ecology 2.8 References and Further
Hunting and Gathering Groups Reading

2.1 INTRODUCTION
In the previous unit, you have studied about the concept and scope of the
subject matter of environmental geography. The study of relationships of
organisms with their biotic and abiotic environments on the Earth may be
defined as ecology. We have introduced the concept of ecology in
Section 2.2. The concept and structure of the ecosystem is also important to
understand the functioning of the Earth’s biosphere. You will get knowledge of
the ecosystem by studying Section 2.3. Humans have developed various
forms of subsistence technologies towards the management of their
environmental resources to cope up with the issues and problems to their
food security since human evolution. Human ecology is a part and parcel of
the larger scientific field of ecology. Section 2.4 explains you the relationship
between people and their environment under the theme of human ecology.
You will study more about human interactions with the environment in
different geographic regions of the Earth like equatorial, mountainous, desert,
and coast in the next Block 2 of this course.

17
Introduction to
Environmental Expected Learning Outcomes
Geography
After completing the study of this unit, you should be able to:
· define ecology;
· explain the concept and structure of ecosystem; and
· describe the human ecology.

2.2 ECOLOGY
We all know that several living organisms including trees, grasses, bushes,
creepers, animals, birds, reptiles, fish and other aquatic animals, fungi,
bacteria, etc. have been living on the Earth since millions of years. Humans
are also part of this list and are not exceptional. To understand various types
of relationships among the organisms and human, we need to study a special
subject called ecology. Ecology is the scientific study of how organisms
interact with one another and with the non-living components of their
environment. The term ecology is derived from two Greek words oikos
meaning house or environment and logia meaning ‘study of’. Ecology
commonly overlaps with the biology, ethology and genetics. Those who study
the affecting nature of biodiversity on ecological functions are called an
ecologist. Let us now understand the concept of ecology in a geographic
perspective. Ecology deals with the organisms that are adapted to their
environment. During the process of interactions among the organisms, they
make use of their surroundings in the form of energy and matter. You might
be knowing that the survival of life depends on the constant flow of energy
and matter. If it stops, then the organisms or living things will die
automatically.

Every organism has some type of relationship or interaction with the other
organism on the planet Earth. It may be for the purpose of food or for getting
energy, for providing help without any benefit from the others, etc. We shall
now understand two sets of questions. Have you ever thought that the
Koalas, a mammal who carry their young in a pouch, live only in Australia
whereas White Tigers live in Indian wild areas? Another question is that the
pine trees grow in the higher altitudinal zones of the Himalayas but not in the
Ganga or Godavari plain regions. Think, what would be the reason for the
distribution of specific plants or animals in a particular region? How the
geological and climatic events influence and effect the life of organisms? To
answer these questions, we normally think of two broad reasons including
ecological reasons and historical reasons of that region. Do you know all of
these can be understood by studying geography, ecology and evolution of
living things, etc. We study these phenomena under the subject of
biogeography. Let us now understand two broad themes of biogeography 1)
historical biogeography and 2) ecological biogeography.

Historical Biogeography: The idea of historical biogeography explains the

way biological organisms are distributed from its place of origin. It means
species are originated at particular place, also called as centers of origins,
and then distributed to other areas based on their capacity and ability for the
movement. The climatic or geological changes might have remained
18
favorable or forcible conditions have necessitated dispersal from the centers Ecology and
of origins. Species were split into one or several other groups. Historical Ecosystems

biogeography is, therefore, concerned with long term, evolutionary periods of

time, on large scale, global areas of living and/or extinct species.

Ecological Biogeography: Ecological biogeography is concerned with

organisms’ response to their surroundings. The biological organisms or a
population generally responds to its physical surroundings and its living
surroundings. Everything that affects an organism is collectively called
environment. Various factors affect the physical surroundings also known as
abiotic environment such as temperature, light, topography, soil, geology,
water, oxygen, salt and acidity levels, and so on. On the other hand, factors
that continuously affect the biotic environment including competing species,
parasites, predators and humans. We must understand that each and every
species can have a certain tolerance levels of environmental factors due to
which they are able to sustain in the environment. No species lives in isolation
from other species. They are characteristically different from each other in
terms of reproductive rate, behavior, movement and so on. In short, the
ecological biogeography is concerned with short-term periods of time, at a
smaller scale, with local, and within habitat of living animal or plant. You will
study more about biogeography in the next Unit 3.

You now know about the ecology which deals with the organism-environment
interactions across ecosystems of all sizes. The ecosystems can be microbial
communities to animals to forest to the Earth as a whole. Let us now
understand the ecosystem.

SAQ 1
Why do you need to study ecology?

2.3 ECOSYSTEM
You are now studying this unit with utmost interest. To complete the entire
unit, you may essentially need to sit and concentrate for considerable time.
For this, you supposed to require some kind of energy. To complete any task
or physical work one should have energy. For getting the energy, we need to
feed our stomach with food. If we are eating food more and more, and not
utilizing the supplied levels of energy then what will happen? You may gain
extra weight, because of the stored energy. It is not only applied to humans
but it is also valid for all living organisms of the ecosystem in several ways.
You will understand the importance of energy in the ecosystem functions by
studying coming sub-sections.

2.3.1 Concept of Ecosystem

We know that the life is associated with the interactions of many organisms.
The living organisms and other components of the earth like land, soil, water,
and atmosphere, etc. are functioning together in a particular relationship.
Therefore, the life is possible on the planet earth. “The system resulting from
the integration of all the living and non-living factors of the environment” is
19
Introduction to called ecosystem which is defined by Tansley in 1935. The word Eco is
Environmental implied to the environment and System means interaction. The biosphere of
Geography
the Earth can be considered as a very big ecosystem in which both abiotic
and biotic components are continuously interacting with each other that
results into structural and functional changes in it. The ecosystem can be
divided as terrestrial ecosystem which includes mountains, forest,
grassland, desert, etc. and aquatic ecosystem for example river, swamp,
delta, marine, etc. The concept of ecosystem is also involved in
understanding the complexity of environment. There are several factors
influencing the environment.

Let us understand the basic characteristics of ecosystems. There are two

fundamental characteristics of ecosystems such as structure and process.

2.3.2 Ecosystem Structure

We understand that an ecosystem is organized into non-living and living
parts. The non-living part is the physical-chemical environment including the
land, water, atmosphere, and soil. The living part, called the ecological
community, contains the set of species interacting within the ecosystem.
Figure 2.1 explains you about the broad structure of ecosystem.

Fig. 2.1: Components of ecosystem.

a) Biotic Components

The living or organic component is also known as biosphere that deals with
the all forms of life. You will also study about non-living components or
physical components spread into three vital spheres viz. atmosphere,
lithosphere, and hydrosphere of the Earth in the forthcoming sub-section. You
must remember that life on the Earth can broadly be divided into three types
as producers, consumers and decomposers.

Producers: Plants, algae, and other tiny aquatic organisms, also called
phytoplankton, are categorized as producers. Producers receive energy from
20 the Sun and use it in the process called as photosynthesis for their needs
drawn from the environment. During this process, they use chlorophyll to Ecology and
absorb light energy for making sugar or glucose from carbon dioxide and Ecosystems

water. Glucose contains stored chemical energy. In turn, they release oxygen
into the air as a byproduct. These organisms produce food for all other
organisms. Producers are also termed as autotrophs.

Consumers: The producers store their energy in various forms like stems,
roots, leaves, flowers, fruits, grains, and seeds, etc. The stored energy of
producers is used by all other organisms as a source of food, either directly or
indirectly, for their growth and movement. These are called consumers for
example, animals, fungi, and bacteria. Consumers are also known as
heterotrophs.

Consumers can further be sub-divided into three categories as primary

consumers or herbivores, secondary consumers or carnivores, and
omnivores. Primary consumers eat producers as a source of food for
example leaf-eating insects, birds, and animals. Secondary consumers
commonly capture and eat other animals. In numerous ecosystems,
herbivores serve as food for the carnivores. Omnivores eat both plants and
animals in their diet, for example, humans and rats. Parasites are also
consumers that live in or thrive on another living organism for example
tapeworm, bacteria, and viruses. These are caused to disease.

Decomposers: Organisms such as fungi and bacteria convert the non-living

organic matter into inorganic material are called decomposers. They live on
dead, excrete, waste products or decaying organisms.

You now know the living components or physical components in the complex
environment of the Earth that plays a prominent role in the biosphere. You will
also understand other components of the Earth which supports life forms.

b) Abiotic Components

Abiotic components are non-living things that influence an organism. As we

know that our planet Earth supports the life or biosphere and other spheres of
the Earth including atmosphere, lithosphere, and hydrosphere. These are also
very important for sustaining life on the Earth.

Life on this earth may not be possible without atmosphere. It acts as a

protective layer for all organisms. Atmosphere consists of many gases
including nitrogen, oxygen, carbon dioxide, etc., that envelops the
environment. Atmosphere is able to separate the Earth from outer space. The
lithosphere is composed of different kinds of rocks and minerals. Earth’s
crust in the lithosphere forms mountains, plateaus and plains, etc. Often, we
call the Earth as a blue planet. Because, water covers nearly 70% of Earth’s
surface. We can observe the water in gaseous form of water vapour which is
present in the atmosphere, liquid form in streams and underground, and solid
state as ice caps. Water is, therefore, ubiquitous and the study of water
comes under the subject of hydrosphere. All these three spheres are known
to support various layers of the life.

So, abiotic factors include energy, non-living matter, living space, and
processes that involve the interactions of non-living matter and energy. We
can further classify the components as energy, climate, weather, minerals, 21
Introduction to water, air, pH, salinity, temperature, soil, sunlight, etc. under abiotic or
Environmental physical environment. It is important for you to study about energy and matter
Geography
because they are vital components in any ecosystem.

2.3.3 Ecological Processes

You might be knowing that any living organism on the Earth requires energy
and matter to grow and function. Where do they get energy from? Yes, the
primary source of energy for almost all organisms is the Sun. Even beneath
the ocean waters, the algae can survive because of the Sun’s energy. For
example, plants obtain the energy from the Sun and they grow. These plants
are eaten by animals to get the energy. Animals are eaten by the other
animals. Based on the Sun’s energy which is received by plants, algae, and
bacteria in a particular region, we can assess the existence of living
components. In an ecosystem, both the prey and predator get the energy
from their source of food, but the energy as well as matter are essential to
build their body structure in which tissues and cells play an important role.
You can further explore what happens to energy and matter as they move
through the biosphere by studying any book of Environmental Sciences or
Physical Sciences.

Matter may be defined as anything like solids, liquids, gases and all living and
non-living organisms that occupies space. Obviously, matter is having mass.
It is composed of atoms such as carbon, nitrogen, and phosphorus, and
molecules for example water (H2O). All the biological organisms get these
atoms and molecules from their environment and are jointly settled as part of
organism’s body structure. After some time, they again return to the
environment through respiration, excretion, or death and decay processes.

Atoms simply are made up of protons (positive particles), electrons (negative

particles), and neutrons (neutral particles). The chemical reactions of
materials facilitate to rearrange the atoms in forming different kinds of matter.
You must remember that an atom, for example, a carbon will always remain a
carbon atom even after several chemical reactions. In chemical reactions,
atoms are neither created nor destroyed. When the same kind or different
kinds of atoms are bonded in a systematic way, a molecule is formed, for
example, oxygen (O2). On the other hand, two or more different kinds of
atoms are bonded to form a compound for example water (H2O). O2 is a
molecule but not compound and H2O is both a molecule and a compound.
Organisms use the molecules and compounds of atoms form their
environment to grow and later decay, and repeat the process form in a cyclic
manner.

You now understood that the energy and matter is constantly being
exchanged within and between the four spheres of atmosphere, lithosphere,
hydrosphere and biosphere. Organisms are grown by taking energy from the
environment and subsequently decay and then return to the environment
again to complete the cycle.

All living organisms at one point of time decompose with the help of fungi and
bacteria on the Earth. During this process, various forms of energy is
created. In the ecosystem, the created energy in all forms eventually leaves
22 the Earth and reradiate into the space. But the energy is again resupplied by
the Sun in the Universe. As we know that the energy is neither created nor Ecology and
destroyed. Hence, the flow of energy is continually reused from the available Ecosystems

resources of the Earth in the cyclic process to maintain a dynamic system.

Ecosystem mainly works on two basic kinds of processes including energy

flow and recycling of chemical elements. Life on the earth’s biosphere
depends mainly on these two processes. Living things require proteins,
carbohydrates, lipids, and nucleic acids. These compounds contain several
elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur,
calcium, magnesium, iron, manganese, boron, zinc, etc. Organisms need
some of these compounds compulsorily or sometimes in smaller amounts.
Cycling process takes place in the biosphere mainly by four key elements of
carbon, phosphorus, nitrogen, and sulfur that are involved in biological,
geological, and chemical processes. These processes are believed to be
operating in circular paths from the environment to living organisms and back
to the environment called as biogeochemical cycles. Some processes in
biogeochemical cycles, such as photosynthesis and respiration, occur rapidly.
Others, such as the formation of coal from the remains of plants, takes
hundreds of millions of years which we known as fossil fuel. Let us
understand interactions between organisms in ecological communities.

2.3.4 Ecological Communities

A set of interacting species are functioning together in their place of living for
creating the environment to continue the life. Interaction of individuals in a
community takes place through feeding on one another. During feeding
between the individuals, the energy and nutrients pass on from one individual
to another individual along the food chains. The linkage of feed between
individuals is known as food chain. For example, eagle eats snakes to rat to
insects to get the energy. The more complex linkages between the organisms
are called food webs. The organisms can be grouped in a food web into
different trophic levels. A trophic level consists of all organisms in a food web
that are the same number of feeding levels away from the Sun’s energy.
Autotrophs are grouped into the first trophic level. The herbivores and
carnivores are members of the second and third trophic levels, respectively.
Carnivores that feed on third-level carnivores are in the fourth trophic level,
and so on. Wastes and dead organisms of all trophic levels are fed by
decomposers which is the highest trophic level in an ecosystem. Refer to
Fig. 2.2, which explains a simple food chain reflecting various trophic levels in
an ecosystem.

Fig. 2.2: A simple food chain in the environment.

23
Introduction to Plants require some amount of water and chemical elements for their growth
Environmental and development. You may be aware of that the plants get all necessary
Geography
nutrients from the soil. However, the depth of their root’s penetration to
absorb the same or slightly different nutrients in a particular region is
significantly diverse for each other type of plants. For example, some plants
grow in high acidic soils and others are resistant to saline soils. In the same
manner, some birds or animals are hunt during night times for their
requirement of food. The activity for obtaining food, they perform hunting or
catching under various conditions. Therefore, it can be understood that the
species might be having the same requirements on one or more axes but not
the same for all. So every organism has developed its own mechanism for
remaining alive. The demands of an organism in its environment in terms of
physical and chemical conditions, space, and food supply is defined as niche.
It simply explains how an individual, species, or population interacts with and
exploits its environment. This is otherwise called adaptation to environmental
conditions. A home of an organism is called as its habitat in which it lives.

You will understand more about humans and their ecology in the coming
section.

SAQ 2
Match the following.

1. Biotic component a) Consumer

2. Abiotic component b) Human
3. Rabbit c) Producer
4. Algae d) Air

2.4 HUMAN ECOLOGY

We, humans, are very peculiar among all other organisms in the biosphere of
Earth. As per ecologist’s definition, the study of the interactions of humans
with their environment is called human ecology. It basically illustrates that
the distribution and abundance of humans as like other organisms. However,
the presence of humans seems to be everywhere and, they do construction
and/or destruction and also affect their own distribution and abundance. Thus,
understanding of human behavior is important to study under the theme of
human ecology.

Behavior of humans is diverse from place to place and time to time. Every
species on the planet Earth has its habitat and are mostly restricted to their
environment. In contrast to other living organisms, humans cannot stay in
some splendid isolation from the rest of nature. Humans have adopted
several traditional skills from others since million of years. On the other hand,
the animals and birds hunt for their survival using the teeth or claws and
beaks. We have developed several technological tools for getting food and
are also utilized for extraction of natural resources from the environment for a
better living.

24
There are several phenomena including genes, culture and environment that Ecology and
interact in different ways and affects human behavior. The study of human Ecosystems

behavior under the discipline of human ecology is involved in understanding

of several cross disciplines. Figure 2.3 represents the view of human ecology
as a multi-disciplinary approach. Since human behavior is so complex and
diverse hence it is essential to understand several other disciplines.

Fig. 2.3: Human ecology deals with multi-disciplines.

Biologists, anthropologists, psychologists, sociologists, geographers,

demographers, historians and economists, etc. have adopted the
ecological/evolutionary approach to humans. No single subject can explain
about the human ecology in detail. Having said that ‘a little knowledge is
dangerous but it is perhaps less dangerous than no knowledge!’. Biologists
study our biological capabilities; anthropology deals with human experience
and what makes us human; psychologists try to understand how people
behave, think and feel; sociologists study about society and human behaviour
and relationships; geographers are concerned with the places and the
relationships between people and their environments; human population’s
size, structure, and their movements over space and time are examined by
demographers; historians write about the past events with related to human
race; and economists study how the societies use scarce resources; etc.
Hence, humans ecology is a more complex subject. From the beginning of
progress of humans, we could find simple societies to more complex societies
now that complexity and diversity offer challenges in understanding humans.

One must understand the development of technologies and culture that taken
place in the history of human development during the past 2-3 million years.
There are several inventions which helped in human transformations of the
environment including fire, language, agriculture, large habitations, sea route
trade and commerce, industrial revolution and technological advancements,
etc. For several years, humans were depended upon environment mainly for
production of food. Let us understand how the human groups were developed
in the natural environment of the Earth at various phases.

2.4.1 Hunting and Gathering Groups

Hunting and Gathering is the oldest form of human activity and most widely
distributed technological method in time and space. It was found that various
pebble tools with the remains of primitive human precursor or hominids
borne in Africa particularly in Ethiopia (around 3 Million years ago). The
ancient hominids were restricted mainly to Africa about 3 million years to 2
million years ago during Pleistocene. After that Homo erectus type hominids
(1 million years ago) were extended to warm and temperate Eurasia. They 25
Introduction to used a kit of stone tools called the Achuelean. About 100,000 years ago,
Environmental Neanderthal hominids were able to live in cold environments and hunt large
Geography
animals with hand-held weapons instead of hurled spears or arrows. Fully
modern humans, Homosapiens, evolved between about 100,000 and 50,000
years ago. Late Pleistocene people (50,000-10,000 BP-Before Present) had
involved in fishing which was common in the Holocene (the past 10,000
years). It was recorded that the modern humans perhaps put their imprints in
Australia and America, the last major habitable land areas of the planet Earth
in the history of human evolution.

Palaeolithic hand axes to more sophisticated tools, in the advancement of

Stone Age, including light killing weapons, spears, bows and arrows,
choppers and knives were extensively used by hunters and gatherers. Their
preparation for food was very simple commonly through open fire and collect
the food with simple wooden bowl. Shelters of these people are often very
simple windbreaks or huts. They had sophisticated tools particularly in
extreme environment for example the Eskimo’s winter clothing, kayaks,
igloos, etc. They have understood greatly animal behavior, plant growth,
flowering and fruiting. The tracking ability of hunters became legendary.
Hunters wait for an injured big animal after hurting it for days to complete the
kill.

Humans were able to explore a variety of diet not only meat including
herbivores from their environment. They had developed communicative skills
such as speech, which the other living organisms cannot express and
describe. At an early stage, humans discovered the use of fire. They had very
simple social systems. Women generally gather food and men play a major
role in hunting because women mostly involved in caring of small children and
young as well. All known hunter-gather subsistence systems were essentially
depended on the contribution of both men and women to succeed.

The hunting-gathering human groups lived before the agricultural ‘revolution’

some 10,000 years ago, in different parts of the globe. Probably with 5 million
total population in the world spreading in very low densities, they mostly
occupied small size of settlements. North America had a great variety of
hunters and gatherers until the mid-19th century. Many of them lived in quite
productive environments.

2.4.2 Horticultural Societies

Human groups in these societies began to use domesticated plants as the
major basis for subsistence. In this system, people work hard to plant, weed,
harvest, and process without assistance from animal traction and mechanized
tools. In the beginning of the Holocene, about 10,000 years ago, the
horticulture was probably developed in the Middle East and slowly spreading
to the other parts.

They made simple tools like stone axe for cutting the trees in the forest,
wooden sticks for digging, and spades for planting and cutting of sugar cane,
maize seeds, etc. Textiles and pottery were common in use. African
horticultural societies began to use iron tools. Though, these tools are hard to
manufacture but iron ores are abundant.
26
Wet tropics with poor leached soils led to the horticulture societies with low Ecology and
human densities. In Amazon and lowland of New Guinea, density of Ecosystems

population might be well within the range of hunters and gatherers. Tribal
Chief is mainly the headmen in horticultural societies. Women play a
significant role as like in hunting and gathering groups in the subsistence
activities because they were responsible for most of the gardening work.

Humans began to domesticate plants and animals rather than hunting and
gathering for food that helped actually to create a base for cultural
advancement of civilization. Human intervention to their environment had
started from foraging to farming through domestication of animals.

2.4.3 Humans as Herders

Human groups in pastoral societies depend mainly on herding domesticated
livestock. The community life basically circles around the needs of the herds.
Nomadic is one of the typical herding societies where the people live in
portable tents or temporary structures and prefer to move considerable
distances from pasture to pasture according to the dictates of ecological
circumstances. They played significant roles in the ecological
processes.These societies were considered to be environmentally specialized
societies. Human adaptation to extensive tracts of grasslands and deserts,
and animal husbandry made a successful activity of pastoralism.

Pastoralists quite freely use carts and caravans for the commercial trade and
raiding because these supposed to be essential in their life. They have good
knowledge in animal husbandry, pasture, and land transportation technology
since their subsistence mainly depending on the herding animals like sheep,
goats, cattle, horses, llamas, yaks, etc. The diet of pastoral people mainly
derives from plant products and small amounts of meat and animal fats.
Leather, horn, wool, and animals for traction became prominent and valuable.
They often trade the animal production for grains, crafts and manufactures,
etc. They may completely depend on herd grazing in an area for a few days to
weeks and move to another area. In some areas of Arabia and Africa, herds
tend to move based on the availability of water. Seasonal migrations are
prominent in much of Europe and Asian regions.
Men of pastoral society are often dedicated to herding larger stock such as
cattle, whereas women engaged in handicrafts, food production and
processing, small-stock herding and the milking of livestock. In human
ecology, the development of pastoral societies has a key role in the
environment, even after the advent of civilization.

2.4.4 Humans as Cultivators

Humans might have foresight in domestication of cattles as these are having
great power when compare to human labour. Our ancestors got recognized
their utility for labour in cultivation or for getting milk. It is said that agriculture
is one of the divine gifts to humankind. Humans became active in mixing of
the horticulture and pastoralism to make an innovative cultivation or
agriculture. With the continued development of agricultural technology in
plant domestication has led to the substantial improvement of production in a
unit of land.
27
Introduction to This type of technological subsistence is more reliable hence it is influenced
Environmental for developing greater population densities and sedentary settlements. It also
Geography
increases the wealth in terms of storing food and luxury items. Farmers in
agrarian societies had developed and utilized the sophisticated technology to
get substantial gains with limited alteration in the environment. The
technology including the usage of plough and draft animals may have helped
the agrarian societies spreading to larger areas. In fact, some advanced
horticultural groups, for example, Inca Empire had developed innovative form
of plough. Plough were first used in the Middle East around 5,000 years ago.
These were simple enough to scratch the light dry soils. Another revolutionary
step was the innovation of wheel, animal-drawn cartage that helped to move
the cultivated products to greater distances. The ox or bull-drawn plough,
notably used in the Indus Basin, are still used in arable lands of several
countries. There were several items included in agrarian tool kit mainly
metallurgy, weaving, marine vessels, pottery, and military equipment, etc.

The agrarian technology supported the higher population densities and larger
settlements through urbanization of population. The sexual division of labor
remains fundamental to the economics of agrarian societies, men’s labor
becomes relatively much more important. Ecological and environmental
variables like climate, soils and topography are main concerns in agriculture,
for example, topography which influences the transport costs, and rainfall and
the availability of water affects the productivity, etc. The important
development in agriculture is irrigation which is supposed to be the earliest
human effects on environment. Because of limited and seasonal rainfall,
irrigation is practiced everywhere from sea level to the limits of cultivation at
nearly 2,000 m altitude.

Pastoralists certainly had made effects on environment through animal

grazing which leads to soil erosion. However, they might have utilized the
earth’s land cover with other living things. But, the agriculturalists drastically
transformed the terrestrial ecosystem through ploughing and seeding the
grasslands by the elimination of a large number of species of native herbs
and grasses. For example, the Prairies of North America introduced new
crops of wheat, corn or alfalfa. In the olden ages, we used to have several
species of plants and animals for domestication. Now it is evident that the
human societies mostly rely on four major crops such as wheat, rice, maize
and potatoes.

With the advancement of agricultural technology, humans tend to control their

environments leading to the formation of large societies and people
movement. Degradation of environment mainly due to global warming, growth
of population and unsustainable use of natural resources are nowadays a
major threat to the ecology and environment of humans. Humans might have
begun the agriculture 10,000 years ago, they could not expected that it would
be a great fundamental change of nature.

2.4.5 Humans in Modern Industrial and Urban Societies

A large chunk of humans started to live in larger settlements in the basin of
the Tigris and Euphrates, the coastal Mediterranean, the Nile valley, the Indus
plain and coastal Peru nearly 6000 to 5000 years ago. In the modern era
28 especially from the late 17th century humans made considerable influence on
the environment through the advancement of culture, science and technology. Ecology and
This accelerated development and its consequences are never and ever Ecosystems

happened before as today’s human transformation of the environment.

Population in commercial and industrial societies are mostly involved in urban
activities like manufacturing, selling, etc., but not directly engaged in food
acquisition. They are hassle free from land-owning lineages, chieftains, or
aristocrats, etc. these we can see in the case of horticultural, pastoral, and
agrarian societies. Industrial and commercial revolution probably started
around 1800 by the human’s innovation of the application of mechanical
sources of energy that led to solve several problems related to the production.
It resulted into a substantial growth of non-farm occupations happened to
occur in the Western Europe and USA by the middle of 19th century. Humans
are still trying industrial advances with an accelerated pace but one can
understand that based on the history of human evolution, there is no
guarantee that the industrial revolution will be completed across the globe.
Europeans used seaborne transportation which is the key development of
commercial/industrial technology to connect global countries for trade and
commerce. By sea-going ships in the sixteenth and seventeenth centuries,
they had transported spices, precious metals, grains, sugar, cloth, dried fish,
and timber, etc. The industrial and commercial technology was largely
extended to powerful stream vessels, railroads, automobiles, and aircraft, etc.
Human access to energy became possible by the late 19th century. They
started decreasing dependency on animals, wind and water. Modern science,
technology and industry have also been applied to agriculture, and progress
made through utilization of fertilizers and pesticides, genetic breeds of plants
and animals. Majority of population began to live in urban areas because of
better transportation and medical and other facilities, the living standards of
people tremendously been improved. Modern science and modern medicine
have led to the population increase even in non-industrial societies.
In the 20th century, human population increased from 1.5 to 6 billion, which
was a time of extraordinary change. The large number of urban
agglomerations has mushroomed in recent decades and are now having their
own environmental problems. Now, everyone can clearly discern the changes
in the planet earth over the past three centuries by humankind. We were used
to alter the forest cover for sustenance of life but now we are altering
fundamental flows of chemical compounds and energy. This will certainly
harm the living organisms of the Earth, which is the only habitable planet, at
large scale.
We human beings affected the plant life seviourly than any other biological
organism of the environment. We are still affecting the animal life, soils,
waters, and climate knowingly or unknowingly in time and space. You will
study about the relationship between the humans and environment in the
coming Block 2 of this course in detail.

SAQ 3
a) Define human ecology.

b) What is the role of nomadic groups in the environment?

29
Introduction to
Environmental
2.5 SUMMARY
Geography
In this unit, you have studied:

· Ecology explains that the interactions between the organisms with one
another and with the non-living components of their environment.
· Ecosystem consists of biotic components such as producers, consumers,
and decomposers and abiotic components including energy, climate,
minerals, water, air, soil, sunlight, etc.
· In the ecosystem, the flow of energy and the cycling of chemical
elements are very important to sustain the life.
· Human ecology deals with the interactions of humans with their
environment. It mainly involves in the distribution and abundance of
humans as like other organisms.
· To understand human ecology better, one need to have knowledge in
several other disciplines like biology, anthropology, geography, sociology,
etc.
· The development of technology and culture from the beginning of human
progress have transformed the environment at large scale.
· Humans had used hunting and gathering technology primarily for wild
game and plant resources.
· Humans by pastoralism involved in domestication of herd animals that
was the main basis for subsistence.
· Horticultural societies can be separated from agricultural societies by
their lack of skills in ploughing and animal traction.
· Agrarian people depended mainly on plant cultivation, and are used
widely draft animals and plough.
· Population in modern industrial and urban cities mainly engaged in trade
and manufacturing activities.

2.6 TERMINAL QUESTIONS

1. Explain the importance of ecological structure and process.
2. Human ecology is a multi-disciplinary field of study. Explain.
3. Differentiate between hunting and gathering, and agriculture subsistence
technologies.
4. Write a note on human’s role in the development of industrial and urban
societies.

2.7 ANSWERS
Self Assessment Questions
1. To understand interactions of organisms in the environment of biosphere.
2. 1-b; 2-d; 3-a; 4-c.
3. a) Human ecology is the study of the interactions of humans with their
environment.
30
 b) Nomadic societies are herders. They are active in herding Ecology and
Ecosystems
domesticated livestock and are considered to be environmentally
specialized societies.

Terminal Questions
1. Refer to Section 2.3.

2. Human ecology deals with different themes of biology, anthropology,

geography, sociology, etc. You may refer to Section 2.4 for more details.

3. Hunting and gathering is the oldest human activity. Humans probably

started practicing agriculture about 10,000 years ago. Refer to the sub-
sections 2.4.1 and 2.4.4.

4. Refer to Section 2.4.5.

2.8 REFERENCES AND FURTHER READING

1. Gerald G Marten (2008). Human Ecology: Basic Concepts for
Sustainable Development. New York: Earthscan Publishers.
2. Goudie, A. (2006). The Human Impact on the Natural Environment: Past,
Present and Future. London: Blackwell Publishing.
3. Marsh, W.M. and John Grossa, Jr. (2002). Environmental Geography:
Science, Land Use and Earth Systems. San Francisco: John Wiley &
Sons.
4. Rajagopalan, R. (2005). Environmental Studies: From Crisis to Cure.
New Delhi: Oxford University Press.
5. Saxena, H.M. (2013). Environmental Geography. New Delhi: Rawat
Publications.
6. Wright, R.T. and Boorse, D.F. (2010). Towards a Sustainable Future.
New Delhi: PHI Learning Pvt Ltd.
7. https://www.nhm.ac.uk/discover/human-evolution.html

31
 Introduction to

3
Environmental
Geography
UNIT

BIOGEOGRAPHY

Structure
3.1 Introduction Taiga Biome
Expected Learning Outcomes Tropical Grassland Biome
3.2 Biogeography Temperate Grassland Biome
Concept and Definition Desert Biome
Scope Arctic Tundra Biome
Classification 3.4 Summary
3.3 Biogeographical Regions- 3.5 Terminal Questions
Biomes of the World 3.6 Answers
Tropical Rainforest Biome 3.7 References and Further
Temperate Deciduous Forest Reading
Biome

3.1 INTRODUCTION
Science and technologies are so advanced today, that human is able to plan
for establishing human settlements on the Moon and the Mars, as early as
possible. Even today, we all know that Earth is the only planet that supports
life in the entire universe. It is because of its relative location in the solar
system. It is astonishing to note that Earth’s surface receives small fraction of
the energy emanated by the Sun which is referred to as insolation or the
incoming solar radiation. This process is primarily responsible for the origin,
evolution and sustenance of life, in its several forms, on our habitable planet.

We have introduced the concept, definition, scope and classification of

biography in Section 3.2. Different types of flora and fauna distributed in
various geographical regions of the world which improve adaptation
capabilities to sustain life in their environment. Section 3.3 will explain you
about these biogeographical regions or biomes of the world.

Expected Learning Outcomes

After completing the study of this unit, you should be able to:

32 v describe the concept and definition of biogeography;

 v explain the scope and classification of biogeography; and Biogeography
v elucidate the biogeographical regions-biomes of the world.

3.2 BIOGEOGRAPHY
3.2.1 Concept and Definition
Centuries back, it was believed that the animals and plants were created by
the great God and they remain same till date. Slowly, during 20th century such
myths had come to an end, when the scientists started proving the biological
process of evolution and geological process of plate tectonics. Carl von Linné
(Carolus Linnaeus), studied medicine and botany in Sweden, who laid the
foundation stones for the modern biogeography during 18th century. He was
developed a comprehensive system of taxonomy and its nomenclature in his
book ‘Systema Naturae’ in 1735. He tried to explain how the particular type
of species gets colonized in a particular environment. This subject what we
call now is ecological biogeography. You might have understood about
historical biography and ecological biogeography themes by studying the
previous Unit 2: Ecology and Ecosystems. Georges Buffon also gave insights
about biogeography that the similar environments found in different regions of
the world, contained different groupings of organisms. His book ‘Histoire
Naturelle’ published in 1761 highlights the number of features of world
biogeography with their possible explanations. He identified that the same
species of mammals of North America were also found in Eurasia, but the
South America mammals are quite different from those of Africa, even though
they live in similar tropical environments. The possible reason could be the
separation of continents through various historically important geological
processes. The climatic influences were also pointed out for the presence of
different flora and fauna in different geographical regions as a reason of the
world.

The origin of biogeography is mainly linked with the observations of

organism’s association with their natural environment that made us to
understand the complexities of natural phenomena. The discoveries of the
biological diversities by the various explorers and naturalists like Alexander
von Humboldt, Louis Agassiz and Charles Darwin had largely created the
interest which ultimately led to formation of the theory of evolution and the
origin of species. The natural selection of each organism in its habitat suitably
explains the concept of adaptation.

To understand further about the concept of biogeography, let us study our

earth’s environment. As all of us know till today that the life is possible only on
the planet Earth because of the Earth’s natural environment that supports
various forms of life. It has four distinctive and vital spheres namely,

A) The Atmosphere
B) The Lithosphere
C) The Hydrosphere and
D) The Biosphere

33
 Introduction to A) The Atmosphere
Environmental
The gaseous layer that encompasses the earth’s surface, is called the
Geography
atmosphere. It consists of several layers and the lower most layer, about
15 kilometers thick, is known as the troposphere, contains the planet’s air. It
is primarily a mixture of nitrogen (N), oxygen (O2), argon (Ar), carbon dioxide
(CO2), neon (Ne), helium (He), krypton (Kr), hydrogen (H2), and water vapour.
The lower part of the next layer is known as the stratosphere, consists of
ozone (O3) that filters the deadly ultra violet (UV) radiation coming from the
Sun. The direct UV radiation from the Sun is capable of destroying all forms of
life on the planet.

B) The Lithosphere
The solid part of the earth’s surface comprising of the earth’s crust (both
oceanic and continental crust) and the upper mantle lying above the partially
melted less rigid as the no sphere, occupying about 21% of the surface area
is called the lithosphere. It is divided into seven major continents and several
islands. The thickness of lithosphere varies from nearly 50 kms under the
oceans and about 100 kms below the continents.

C) The Hydrosphere
Earth is often called as blue planet as it holds water. The hydrosphere
corresponds to all the areas on the earth’s surface and underground covered
by water in all the three of its physical forms, namely, the water, water vapour
and ice. While water vapour is mostly found everywhere, water and ice
occupies about 79% of the earth’s surface. It includes all the water bodies of
the world such as the oceans, seas, lakes, ponds, rivers, groundwater
aquifers, glaciers, ice-sheets and the ice capped polar regions.

D) The Biosphere
There is a thin layer constituting the zone of contact between the atmosphere,
hydrosphere and lithosphere, formed on and near the earth’s surface. This
thin layer where life exists in abundance in innumerable numbers and variety
of organisms and hence, is known as the biosphere. It covers the lower layer
of atmosphere and the land surface of lithosphere, and almost the whole of
hydrosphere. Therefore, the biosphere comprises of both land and oceanic
areas. For detail description of earth’s four spheres, you may refer to the 1st
Semister course of Physical Geography (BGGCT 131).

As you have studied in Unit 2, the life-forms or the ‘biota’ comprising mainly
of micro organisms, plants and animals including human life in the biosphere.
They depend on the abiotic conditions such as the light, air, water and soils,
etc., prevailing in their surroundings for the sustenance. The abiotic conditions
vary from place to place and also from time to time and so is the distribution
of the biota, accordingly. Ernst Haeckel (1876) wrote that “the actual value
and invincible strength of [Darwin’s] Theory of Descent…[is] that it explains all
biological phenomena, that it makes all botanical and zoological series of
phenomena intelligible in their relations to one another”. The science of
biogeography is involved in documentation and explanation of spatial patterns
of biological diversity in an understandable manner. Hence, biogeography
can be defined as “the study of the temporal as well as the spatial distribution
of the living beings (the biota) and their living conditions (the abiotic
34
conditions) in the biosphere”. Naturally, this study includes the interaction Biogeography
between different types of life forms and interaction between them and their
abiotic conditions.

3.2.2 Scope
The scope of biogeography is wide. The subject matter of biogeography is
mainly concerned with biology and geography which studies about the
biosphere in particular. We all know that environment is very dynamic in
nature. It is subjected to several changes by several factors such as the
changes in climates, unscientific exploitation of natural resources, human
warfare, etc., which leaves a great impact on the earth’s surface, especially,
on the biosphere and all the living beings. The study of biogeography thus
helps humans to know their environment fairly well. It will also help in
perpetuating their race as well as improving their standard of living from time
to time, forever. The biogeography overlaps the boundaries of multi-
disciplinary subject themes of botany, zoology, hydro-geomorphology,
climatology, geology, pedology, and anthropology. Biogeography initially
developed based on taxonomy investigations like identifying and classifying
plants and animals and later it is supplemented on ecological and analytical
lines. The present and past distribution of organisms are traditionally studied
under the subject matter of biogeography.
Since 1960’s, researchers have been using computer related technologies for
identifying problems in the fields of ecology and biogeography. Now,
multivariate statistics coupled with satellite remote sensing and global
positioning system studies are extensively being used with the help of
computers and software packages as well. These scientific techniques helps
us to locate and map the distribution and pattern of living organisms more
precisely even in inaccessible remote areas. Based on above advancements
and avenues of enquiry and increased modern methods of experimentation
and analysis, the subject of biogeography has a lot of scope for
understanding our nature scrupulously. Modern biogeography deals with the
nature by studying all patterns of geographic variations, from genes to entire
communities and ecosystems, and elements of biological diversity that vary
based on their area, isolation, latitude, depth and elevation. You could
understand now the biogeographer who must have the knowledge in
phytogeography, which explains about plants, and zoogeography which
studies the animals. Therefore, a biogeographer needs to acquire and
synthesize a huge amount of information across a broad range of temporal
and spatial scales.

3.2.3 Classification
In the modern era, late 19th century, the British P.L. Sclater, ornithologist, and
A.R. Wallace, biogeographer and naturalist, categorized the geographical
distribution of fauna into two creations as the Old World (Creatio Paleogeana)
consisting Europe and Asia (Northern Part), Africa (South of the Sahara),
India and Asia (Southern Part), Australia and New Guinea; and the New
World (Creatio Neogeana) which comprises of North America and South
America. They identified six regions and its sub-regions including Nearctic,
Neotropical, Palaearctic, Ethiopian, Oriental, and Australian. Most of the
biogeographers are still following this classification scheme. 35
 Introduction to The subject of biogeography is broadly classified into two main fields of study.
Environmental
They are a) Historical (Paleo) Biogeography and b) Ecological Biogeography.
Geography
Each field, however, looks at phytogeography (the past and present
distribution of plants) and zoo-geography (the past and present distribution of
animals).

a) Historical or Paleo-Biogeography
Historical biogeography which is also called as paleo-biogeography. It studies
the past distribution of species. There are a number of biotic and abiotic
factors that are used to explain the past and present patterns of distribution. It
considers several biological factors such as adaptation, predation and
competition on the one hand and physical factors like geology, climatic and
evolutionary events, soil and light on the other hand to determine the
development of certain species in a particular area. The historical approach
would help us to reveal that there are more species in the tropics than at high
latitudes because the tropics experienced less changes in climates during the
glacial periods. This led to fewer extinctions and more stable populations
thrived over the time. This study often includes paleo-geographic ideas by
considering plate tectonics. This type of research uses fossils to show the
movements of species across space, via moving continental plates.

b) Ecological Biogeography
This study looks at the factors responsible for the current distribution of plants
and animals. The most common fields of research within ecological
biogeography are i) climatic equability, ii) primary productivity, and iii) habitat
heterogeneity.

i) Climatic equability: This study deals with the variations between daily
and annual temperature values. It is very difficult to survive in areas with
high variation between the diurnal and seasonal temperatures. Due to
this reason, we could find fewer species at high latitudes, when
compared to the tropics which have a steadier climate with fewer
variations in temperature. Daily temperature patterns are also modified by
topography even in the absence of vegetation.
ii) Primary productivity: This study considers the ‘evapo-transpiration’
rates of plants. Evapotranspiration refers to the release of water into the
atmosphere as water vapor, both by the physical process of evaporation
and by the biological processes of transpiration and respiration.
Wherever, evapotranspiration is high at higher temperatures, so is the
plant growth. The tropics generally are warm and moist that allows more
plants to grow. On the other hand, in higher latitudes, it is simply too cold
for the atmosphere to hold enough water vapour, thereby, limiting the
number of plants that are present there.
iii) Habitat heterogeneity: It leads to the presence of greater biodiversity.
Habitat heterogeneity explains that the increase in number of habitats
leads to an increase in the number of different species in a natural
landscape.

SAQ 1
a) What are the four spheres of Earth?
b) List out the important fields of biogeography.
36
3.3 BIOGEOGRAPHICAL REGIONS-BIOMES OF Biogeography

THE WORLD
As you know that the Earth is the only planet that supports life in the entire
universe. The organisms such as plants, animals, humans, and millions of
micro-organisms live in this planet. Interestingly, the distribution of these
organisms is not uniform and it is primarily influenced by the climatic
conditions, mainly, temperature and rainfall.

You may understand that the living organisms including plants and animals
are found in areas where they suitably adopted in that climatic condition.
Therefore “a distinct-ecological community of plants and animals, living
together in a particular climate” may be the suitable definition of a ‘Biome’.
The following are recognized as the major biomes of the world:

1. Tropical Rainforest Biome

2. Temperate Deciduous Forest Biome
3. Taiga Biome
4. Tropical Grassland Biome
5. Temperate Grassland Biome
6. Desert Biome
7. Arctic Tundra Biome
Refer to Fig 3.1, which gives you an idea about the major biomes that are
distributed across the world. In this context, let us now study the
characteristics and importance of these biogeographical regions or biomes of
the world.

Fig. 3.1: Major biomes of the world.

(Source: NASA, 2020; https://earthobservatory.nasa.gov/biome).

3.3.1 Tropical Rainforest Biome

The tropical rainforest biome is characteristically hot and moist in condition,
and is distributed around the earth’s equator. The tropical rainforests are
largely found in South America, Africa and Southeast Asia. These 37
 Introduction to biogeographical regions receive rainfall evenly between 1500 mm and 4000
Environmental
mm throughout the year. The average temperature is approximately 25° C all
Geography
year round and humidity also ranges from 77 to 88%. The combination of
constant warmth and abundant moisture makes the tropical rainforests the
most favourable environment for many plants and animals. As a result, this
biome contains the greatest biodiversity by housing a large number of species
of plants and animals in the world.

The micro-organisms including bacteria and fungi play an important role as

the hot and humid conditions make an ideal environment for their
development. They are able to decompose the organic matter very quickly
and the nutrients are quickly consumed by the vegetation. The nutrients
absorbed by the soil are leached out by the abundant rainfall, thereby leaving
the soil infertile and acidic.

Flora: You will be astonished to know that the tropical rainforest areas
receive approximately 12 hrs of sunlight in a day. Of which, only 2% of total
sunlight, reaches to the ground. This biome has the densest vegetation on the
earth’s surface, often forming three layers - the canopy of vegetation, the
under storey and the ground layer. The canopy of vegetation is created by the
apex portion of tall trees. The under storey prevents sunlight to reach the
ground and hence, very little vegetation is able to survive at the ground level.

The flora is highly diverse. The trees are generally tall, nearly 20-35 m high
with strengthened trunks and shallow roots, mostly evergreen, and with large
dark green leaves. Plants such as orchids, bromeliads, vines, ferns, mosses
and palms are present in these regions. Survival of a plant in the tropical
rainforest depends on its ability to tolerate constant shade or to adapt
strategies to reach sunlight.

Fauna: Tropical rainforests provide sufficient water and food constantly than
any other biome of the world. Hence, the large number and variety of animal
species are accustomed to live in these regions. Small animals including
insects, birds, rodents, frogs, lizards, possums, snakes and monkeys live in
the tropical rainforests and many of them never set their foot on the ground.
Larger animals include tigers, leopards, gorillas, rhinoceros, and so on.
Some animals use the tall trees and under storey for shelter and as a source
of food. For example, the toucan, sloth, camouflage and blue-green algae
also survive in the rainforest.

3.3.2 Temperate Deciduous Forest Biome

Temperate deciduous forest biomes are geographically located between the
polar regions and the tropics. These are also known as the Mid-Latitude
deciduous forest biome. These forests are spread over the eastern parts of
the United States of America and Canada, central European regions, and
parts of China and Japan. Air masses from both the cold polar regions and
the warm tropical regions largely affect these biogeographical areas which
lead to the significant changes in climatic conditions.

38
 Biogeography

Redeye Frog
Toucan

Tiger
Fig.3.2: Major Animal Species of Tropical Rainforest Biomes
(Credit: Drawn by Master K. Shanmukhashri Yaswanth)

Temperature ranges between -30oC and 30oC while precipitation varies from
750 to 1500 mm annually. You will find a major chunk of the human
population in this geographical region. The significant vegetation is deciduous
forest covered with an abundance of deciduous trees. “Deciduous” means ‘to
fall off’, or ‘shed’, seasonally. Just as the name implies, these trees shed their
leaves during autumn season every year. As they fell off, they decay, and the
nutrients contained in the leaves are absorbed by the soil. Due to
decomposition of trees and leaves, the soils of this biome tends to be very
fertile.
Flora: Trees of this biome include maple, oak, hickory, birch, magnolia,
hemlock, spruce, fir, etc. A deciduous forest typically creates several layers of
plant growth. Top layer is created by the tall deciduous trees with moderate
canopy as it allows sunlight to reach the ground. The shorter species of trees
make up the second layer of plant growth. Shrubs and forest herbs include
wild flowers and berries are able to grow quickly taking an advantage of
intervening period of shedding leaves by deciduous trees. The last layer
includes mosses and lichens that largely grow on tree trunks.
Initially the deciduous trees begin to produce thin, broad, light-weight leaves
and are turned to green due to warm temperature and plenty of sunlight.
However, when temperatures are cold, the broad leaves expose too much
surface area to water loss and leads to tissue damage. When the temperature
dips coupled with limited sunlight, the trees start to shed their leaves.
Deciduous trees stay dormant in the winter season and bloom again in the
spring season. 39
 Introduction to Fauna: In this geographical region, we largely find a wide varieties of
Environmental
mammals, birds, insects and reptiles. It includes bears, raccoons, squirrels,
Geography
skunks, woodmice, salamanders, frogs, turtles white-tailed deer, elk, bison,
bobcats, mountain lions, timber wolves, and coyotes, etc. As the season
changes, the animals in this biome try to adopt hibernation and others are
able to migrate to suitable lower areas that enable them to live in the habitat.
We can find a wide variety of birds that migrates and many of the mammals
hibernating during cool temperatures when food is in short supply. During the
summer, squirrels, chipmunks, and jays use to gather the nuts and seeds,
and store them in the hollows of trees for feeding during the winter months.
Cold temperatures help to prevent decomposition of the nuts and seeds.

Squirrel Bear
Fig. 3.3: Major Animal Species of Temparate Delidhous Forest Biomes
(Credit: Drawn by Master K. Shanmukhasri Yaswanth)

SAQ 2
a) What is the important character of tropical rainforests?
b) What is the meaning of deciduous?
c) Which season is favourable for shedding leaves by the deciduous trees?

3.3.3 Taiga Biome

If you see the Fig. 3.1, you will notice green colour portions near the polar
regions. This is the place where you will find the largest biome in the world,
the ‘taiga’ which is distributed between 500 N and 600 N latitudes in the
northern hemisphere. The taiga biome is also called as the Boreal forest or
Coniferous forest biome. Since, it is very near to polar region, it is strongly
affected by cold temperatures. This cold biome stretches across the northern
portions of North America, Europe and Asia. The maximum area is occupied
by Siberia which is famously known as Siberian desert. Moscow in Russia
and Toronto in Canada are the largest human population cities found in the
southern regions of taiga. However, the northern areas are relatively
unpopulated, hence, it is called cold desert.
The temperatures significantly vary during the winter and summer seasons as
winters are long and cold and the summers are short and cool. The average
temperature in summer ranges from -40°C to 20°C and precipitation varies
between 300 and 900 mm annually with the occurrence of snow fall during
winters. In the lower latitudes, precipitation is more evenly distributed
throughout the year.
40
Do you know, this taiga region was covered with glaciers several millions of Biogeography
years ago. You will find gouges and depressions like topography which
proves that the position of glaciers were slowly receded. These gouges and
depressions are frequently filled with precipitation often snow and ice,
creating bogs and lakes geomorphic structures. The soil found in the taiga is
low in nutrients and highly acidic in nature. It is rocky and covered with un-
decayed leaf litters. Patches of permafrost can also be found in some
geographical areas of the taiga.
Flora: We all are aware of the climate which strongly influences the living
capabilities of organisms. The severe cold climates of taiga do not support a
large number and variety of plant life. The most common type of trees found
in the taiga are the conifers. Four kinds of conifers, ever greens, spruce, fir
and pine, and the larch (a deciduous tree) are found in the taiga. Birch and
aspen are also seen in this biographical region of the world.
The leaves of evergreens are always green as they don’t drop their leaves
when temperatures cool. They conserve the limited energy available to them
and may use it for structural growth rather than producing leaves. Due to
harsh climates, the ground freezes during the winter months and plant roots
are unable to get water. The typical structure of leaves, the conical shape,
which allows the snow to slide off the branches, thus protecting them from
severe damage in this taiga biome.
Fauna: Many of the animals and birds are not able to survive round the year
because of cold climates. Examples of the animals living in the taiga are
moose, deer, bear, bobcats, squirrels, chipmunks, ermine and moles.
The taiga is home to many insects and birds such as the bald eagle, wood
peckers and warblers. Taiga is considered to be a wonderful breeding place
for a wide variety of insects. Many migratory birds come to nest and feed on
the huge insect population. The bogs and lakes/ponds are the main source of
water which often remains filled during summer season. The major
phenomenon we can observe in this region is that most animals migrate to
warmer climates once the cold weather begins. Some animals live in the
taiga by hibernating when temperatures drop. They with stand the extreme
cold temperatures by producing a layer of insulating feathers or fur to protect
them from the cold.

Bald Eagle Coniferous Tree

Fig. 3.4: Major Species of Taiga Biome
(Credit: Drawn by Master K. Shanmukhashri Yaswanth)
41
 Introduction to 3.3.4 Tropical Grassland Biome
Environmental
Geography The tropical grasslands or shrub lands are also popularly called as
Savannah. It is characterized by tall grasses and occasional trees. Such
regions also includes chaparral and woodland areas.

The countries like Botswana, Namibia, Kenya, Brazil, India, Australia and
USA are covered with large portions of Savannahs. These biogeographic
regions are having 6 to 8 months summer season and rest a dry winter
season. There is wide range of rainfall variations as low as 250 mm/year and
upto 1250 mm/year high in some areas. The rain is unpredictable, varying
from month to month. Due to different climate and soil conditions or
agricultural practices, these regions are characterised by limited growth of
trees. Grassland regions are now severely altered by humans in order to plant
the crops by burning the huge traits of grasslands and felling off the trees.

Flora: A wide variety of grasses is predominant plant life which grows in the
Savannahs. The grasses in some areas grow about 2 to 3 meters tall that is
named as ‘Elephant Grass’. Scattered trees or small group of trees can also
be found in particular locations. The acacias and baobab trees are common
examples seen in African Savannahs. A ‘Prairie’ is named for savannah
biome where trees are almost absent. Due to fires, the grasses are burnt.
However, they grow with the help of water and other water reserves below the
ground. Fire is a phenomena which stimulates a fresh growth and replenishes
the soil with nutrients. Baobab trees produce a small size of leaves during the
wet season that helps limit water loss. They store water in its large trunk to
survive during drought conditions. The acacia tree also develops long
taproots that can reach deep underground water source.

Baobab
Acatia
Fig. 3.5: Flora of Tropical Grassland Biome
(Credit: Drawn by Master K. Shanmukhasri Yaswanth)

Fauna: You might be knowing that the variety of animals are housing by the
African Savannahs. Elephants, lions, leopards, cheetahs, rhinos, zebras,
hyenas, ostrich, and starlings are some examples. The rainwater is the
important source of water supply where birds, insects and several animals
thrive in the Savannahs. Most of the birds and animals migrate in search of
42 water to places within the biome or outside and is a common phenomenon.
As and when rainy season starts they come back to their habitats. Fires are Biogeography
common in this dry grass region and some animals run fast and birds fly, and
some are stayed in burrows for escaping from the fires.

Lion

African Elephant

Giraffe
Fig. 3.6: Fauna of Tropical Grassland Biome.
(Credit: Drawn by Master K. Shanmukhasri Yaswanth)

3.3.5 Temperate Grasslands Biome

As we discussed earlier, the name itself suggests that these are characterized
by a dominance of grass. Temperate grasslands are distinguished from
tropical grasslands by the absence of trees and shrub plant life. These are
found in the north and south of the tropics. The major temperate grasslands in
the world are:
1. Veldts of South Africa
2. Puszta of Hungary,
3. Pampas of Argentina and Uruguay
4. Steppes of Russia and China
43
 Introduction to 5. Plains and Prairies of North America
Environmental
Geography 6. Downs of Australia and New Zealand
Temperatures vary significantly from summers to winters, and the amount of
rainfall is lesser in temperate grasslands than in Savannas. The annual range
of temperature varies between – 40oC and 38oC. The average annual rainfall
ranges from 500 mm to 800 mm which is considered to be low. There is a
positive relationship with the growth of grass to the amount of rainfall. The
high rainfall results into the growth of grass in this biome. Drought and fire
plays a greater role in keeping the trees from taking over the grasslands as
like that of tropical grasslands.
Flora: Plants growing in the steppes, usually in dry habitats, are more or less
30 cm in height. The various species of grasses include purple needle grass,
blue grama, buffalo grass, sagebrush, spear grass, cacti, and galleta. The
famous plant called ‘sweet’ (Adonis Vernalis) grows in steppes that is widely
used as a tranquiliser and a powerful medicine for treating heart and kidney
diseases.
Fauna: The fauna like bison, saiga antelope, coyotes, bobcats, wolf, prairie
chicken, badgers, eagles, hawks, owls, snakes, etc., can be found in this
biogeographical region. The saiga antelope has a large, inflatable, humped
and movable nose, living in the extremely cold and dusty environment. Today,
people use steppes to graze livestock and to grow wheat and other food
crops. Overgrazing, ploughing, and irrigation are being affected the steppes
on large scale.

Saiga Antelope Butterfly

Fig. 3.7: Major Species of Temperate Grasslands Biome.
(Credit: Drawn by Master K. Shanmukhasri Yaswanth)

SAQ 3
Match the following:
1) Taiga forest a) Tropical grasslands
2) Steppe b) Boreal forest
3) Savannah c) Temperature grasslands
4) Pampas d) Argentina

3.3.6 Desert Biome

We all are aware of a ‘desert’ which means dry area. In this biogeographical
regions, the annual precipitation varies from about 100 mm to as much as 370
mm. You will find the localized seasonal rainfall in this biome and it is difficult
44
to predict when or where it will occur. Interestingly, in Atacama desert located Biogeography
in Chile, we could not measure rainfall for several years at several places.
Deserts can be either hot or cold or semi-arid. The type of desert is assessed
by its geographic location, atmospheric pressure, and proximity of mountain
ranges, etc. The world’s known deserts are: Antarctic Desert (Antarctica),
Arctic Desert (Arctic), Sahara Desert (Africa), Arabian Desert (Middle East),
Gobi Desert (Asia), Patagonian Desert (South America), Great Victoria Desert
(Australia), Kalahari Desert (Africa), Great Basin Desert (North America),
Syrian Desert (Middle East) and so on.
You can find deserts along the coast called coastal deserts located on the
west coasts of continents between 20o to 30o latitude, for example, Atacama
and Namib deserts. Prevailing winds blow in an easterly pattern and prevent
the moisture from moving onto the land. Semiarid deserts are not only
located far from the moisture, but are frequently associated with high
mountain ranges that produce a rainshadow effect. Examples are Gobi desert
of Mongolia and Great Basin desert, etc.
Deserts have large daily temperature variations. Temperatures are high
during the day because there is very little moisture in the air to block the
Sun’s rays to reach the Earth. Once the Sun goes down, the heat is
absorbed. During the day, the temperatures become very high and the night’s
record low temperatures which makes survival in the desert a difficult task.
Flora: The abundance and variety of plant life in these regions are including
short grasses, sage brush, creosote bushes, and cacti, etc. Short grasses are
grown in almost all desert areas. The typical examples are the saguaro cactus
(Sonoran desert) and spinifex (Australian desert).
Because of the dry climate, plants have developed taproots as long as 6 to 9
meters for capturing the water. Other characteristic root systems are
horizontal way in which roots penetrate just below the surface and extend far
beyond the plant canopy. The root system of the mulga tree is another unique
system of collecting water. The tiny leaves of the tree capture the water from
rain and funnel it down along the branches to its centre. The water then falls
to the ground near the trunk of the tree where the roots are concentrated and
survived. Some desert plants store water in their roots, stems, leaves or fruit
which are referred to as succulents, for example, cactus. Desert plants can
retain moisture by limiting water loss through their leaf surface, their size,
sheen or texture of their leaves.

Date Palm Saguaro Cactus Opuntia Cacti

Fig. 3.8: Major Plant Species of Desert Biome
(Credit: Drawn by Master K. Shanmukhasri Yaswanth)
45
 Introduction to Fauna: You might have come to the conclusion that the desert regions does
Environmental
not support the animal life. But, it is not one hundred percent true. Many
Geography
reptiles, insects, birds, and small animals do also survive in the desert biome.
The kangaroo mice of North America and the bilby and red kangaroo of
Australia are just a few examples of small animals that live in the desert. You
will not find large animals in the desert regions except camel. Camel has
ability to store water in large quantities in several sacs in its abdomens and
can survive without water for many days. Animals in this region seek shelter
by burrowing into the ground. The animals remain inactive during the hot
daytime. They hunt at night when temperatures are cool.

Camel
Fig. 3.9: A Desert Animal
(Credit: Drawn by Master K. Shanmukhasri Yaswanth)

3.3.7 Arctic Tundra Biome

Arctic tundra is a typical biogeographical regional biome and is distributed
across northern Alaska, Canada, and Siberia. Tundra is a Finnish word which
means ‘treeless’. These regions experience long and cold winters as well as
short and cool summers. An average annual precipitation of about 250 mm
and dry winds make desert like conditions in Arctic Tundra. The permafrost
(the sub-soil) consisting mostly of gravel and finer material remains below the
freezing point throughout the year. It is characterized by the lack of cracks
and pores, which creates and get obstacles for plant roots as well as for water
penetration.
During the summer, Arctic tundra is typically covered with a lot of surface
water. The water cannot percolate into deep grounds due to permafrost
conditions, forming as pools of water on the surface. These regions receive
low amount of sunlight. Though, the Sun remains in the sky for 24 hours a

46
day during the summer, it stays close to the horizon and provides only low Biogeography
intensity sunlight.
Flora: In the Arctic tundra, due to short supply of sunlight, even in the
summer, plants are able to penetrate roots at very shallow depth. Permafrost
prevents plants from sending their roots down the past pores. Hence, Arctic
plants have a very short growing season. But interestingly, there are
approximately 1700 types of plants thrives well in this region by facing severe
conditions and the short growing season spanning hardly about 50 to 90 days
period. Some of the plants include mosses, lichens, shrubs, and grasses
which grows in this biome. A small leaf structure is another instance of
physical adaptation that helps plants to survive. By producing small leaves,
the plant is able to retain more moisture, which it has stored.
Fauna: Animals rarely live in the Arctic tundra throughout the year. Most of
the birds and animals use it as a summer home. The musk-ox, Arctic wolf and
brown bear are adopted to live year around in these extreme climatic
conditions. Animals need to find ways to stay warm in order to survive in the
long and cold winter months. Animals including lemmings, voles, caribou,
arctic hares, squirrels, arctic foxes, wolves, polar bears, and migratory birds
such as ravens, snow buntings, falcons, loons, sandpipers, terns, snow birds,
and various species of gulls are some of the examples.
The peculiar character of animals in this regions is the hibernation which
means sleeping during the winter. The food eaten by bears during the
summer is stored as a layer of fat underneath its skin. This fat is slowly
converted into energy for sustaining life during the hibernation. Another
example is that the layer of long fur protects the musk-ox from the cold wind
and icy water. The hooves of the musk-ox are large and hard that allows
breaking the ice and drinking the water underneath.

Polar Bear
Fig. 3.10: Major Species of Arctic Tundra Biome
(Credit: Drawn by Master K. Shanmukhasri Yaswanth)

SAQ 4
a) Name any two cold deserts.
b) What is the meaning of Tundra?
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 Introduction to
Environmental
3.4 SUMMARY
Geography
In this unit, you have studied:

· The life of organisms exists on the earth which is known as biosphere.

This is the zone of contact between the atmosphere, lithosphere and
hydrosphere.
· The life forms on Earth depends on the abiotic conditions such as the
light, air, water and soils, prevailing in their immediate surroundings.
· The abiotic conditions vary from place to place and also from time to
time, so is the distribution of the biota, accordingly.
· Biogeography may be defined as “the study of the temporal as well as the
spatial distribution of the living beings and their living conditions in the
biosphere”.
· You have also studied the major biogeographical regions or biomes of
the world such as: the tropical rain forest biome, the temperate deciduous
forest biome, the taiga biome (the Boreal forest biome), the tropical
grasslands biome (the Savannah), the temperate grasslands biome (the
Steppe), the desert biome, and the Arctic tundra biome.

3.5 TERMINAL QUESTIONS

1. Define the biogeography and explain scope of biogeography in detail.
2. What are biographical regions or biomes of the world? Explain any two
important biomes of the world.

3.6 ANSWERS
Self Assessment Questions
1. a) They are the atmosphere, the lithosphere, the hydrosphere, and the
biosphere.
b) Historical biogeography and ecological biogeography.
2. a) Hot and moist in condition.
b) Deciduous means “to fall off”.
c) During the autumn season, the deciduous trees shed their leaves.
3. 1 b; 2 c; 3 a; 4 d
4. a) Antarctic and Gobi deserts
b) Treeless
Terminal Questions
1. Refer to the Section 3.2.

2. The major biogeographical regions or biomes of the world are the tropical
rain forest biome, the temperate deciduous forest biome, the taiga biome
(the Boreal forest biome), the tropical grasslands biome (the Savannah),
the temperate grasslands biome (the Steppe), the desert biome, and the
Arctic tundra biome. Refer to the Section 3.3.
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 Biogeography
3.7 REFERENCES AND FURTHER READING
1. Barry Cox, C. and Peter D. Moore (2010). Biogeography: An Ecological
and Evolutionary Approach. New Jersey: John Wiley & Sons.
2. Donald K. Fellows (1975). The Environment of Mankind: An Introduction
to Physical Geography. California: Hamilton Publishing Company.
3. Huggett, Richard J. (2004). Fundamentals of Biogeography. New York:
Routledge.
4. Kiran B. Chhokar (2004). Understanding Environment. New Delhi: Sage
India.
5. Marsh, W.M. and John Grossa, Jr. (2002). Environmental Geography:
Science, Land Use and Earth Systems. San Francisco: John Wiley &
Sons.
6. Mathur, H.S. (2003). Essentials of Biogeography. Jaipur: Pointer
Publishers.
7. Rajagopalan, R. (2005). Environmental Studies: From Crisis to Cure.
New Delhi: Oxford University Press.
8. Saxena, H.M. (2013). Environmental Geography. New Delhi: Rawat
Publications.
9. Wright, R.T. and Boorse, D.F. (2010). Towards a Sustainable Future.
New Delhi: PHI Learning Pvt Ltd.
10. NASA, 2020. National Aeronautics and Space Administration, United
States of America. https://earthobservatory.nasa.gov/biome.
11. https://www.britannica.com/science/biome
12. https://ucmp.berkeley.edu/exhibits/biomes/

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 Introduction to
Environmental
GLOSSARY
Geography
Abiotic : These are nonliving things that influence an organism.
Components Abiotic factors include energy, nonliving matter, living
space, climate, weather, minerals, water, air, etc.
Atmosphere : The gaseous layer that encompasses the earth’s
surface is called the atmosphere.
Atoms : They are made up of protons, electrons, and neutrons.
Autotrophs : Producers or phytoplankton are termed as autotrophs.
Biome : It is a distinct ecological community of plants and
animals, living together in a particular climate
Biosphere : It represents the thin layer constituting the zone of
contact between the atmosphere, hydrosphere and
lithosphere. It supports all forms of life on the Earth.
Biotic : The living or organic components is called biotic
Components components.
Carnivores : These are secondary consumers who capture and eat
other animals.
Consumers : They depend on producers for their source of food in
the growth and development. Examples of consumers
are animals, fungi, and bacteria.
Cultivators : They are also called as farmers in agricultural
societies and are utilizing the sophisticated technology
by mixing horticulture and pastoralism to get
substantial production in unit land.
Decomposers : They convert the nonliving organic matter into
inorganic material which are called decomposers.
These live on dead, excretes waste products or
decaying organisms.
Ecological : It is concerned with short-term periods of time at a
Biogeography smaller scale and local or within the habitat of living
animals or plants.
Ecology : It is the scientific study of how organisms interact with
one another and with the non-living components of
their environment.
Ecosystem : The system resulting from the integration of all the
living and non-living factors of the environment.
Environmental : Description of different components of environment
Geography and interactions of human with these components and
their spatial variation over the Earth’s surface.
Food Chain : The linkage of feed between individuals is known as
food chain.
Food Web : It is a more complex linkage between the organisms.
Herbivores : These eat producers as a source of food for example
leaf-eating insects, some birds and animals.
Heterotrophs : Consumers are also known as heterotrophs.
Historical : It deals with long-term periods of time at a large scale,
Biogeography and global areas of living and/or extinct species.
Human : The subject of human ecology studies the interactions
Ecology of humans with their environment and illustrates
human’s distribution and abundance.
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Humanmade : It is also referred to social environment which deals Biogeography
Environment with culture, language, social conditions, health, living
conditions, and economic capability of the people in
an area.
Hydrosphere : It corresponds to all the areas on the earth’s surface
cover by water in all the three of its physical forms
such as water, water vapour and ice.
Insolation : It is also referred to as the incoming solar radiation. It
explains the small fraction of energy emanated by the
sun that reaches the earth’s surface. It is responsible
for the origin, evolution and sustenance of life in the
world.
Lithosphere : It corresponds to the solid part of the earth’s surface
comprising the earth’s crust and the upper mantle.
Matter : It is anything like solids, liquids, gases and all living
and non-living organisms.
Omnivores : They eat both plants and animals for example most
humans and rats.
Parasites : These are consumers living in or on another living
organism for example tapeworm, bacteria, and
viruses.
Pastoralists : These human groups depend mainly on herding
domesticated livestock.
Physical : It is also known as the natural environment which
Environment includes all living and non-living things that occur on
the Earth.
Producers : Sun energy is used for photosynthesis for their needs
in the environment. Examples are plants, algae, and
other tiny aquatic organisms.

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 Introduction to
Environmental
Geography

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