Surendra patel

1. K.G. ARTS & SCIENCE COLLEGE RAIGARH (C.G.)
Year - 2019-20
Deparment of zoology & research center
Subject :- Environmental physiology & ecology
Seminar topic:- Habitat & Niche concept
Guided by:- Submitted by:-
Prof. Vinita Pandey mam. Surendra Patel
M.Sc sem I zoology

2. SYNOPSIS :-
1. Introduction
2. History
3.Types of habitat
4.Types of niche
5. Niche breadth & overlap
6. Diffirence between niche & habitat
7. Concepts & principals
8. Conclusion
9. Refrences

3. 1.INTRODUCTION :- Habitat refers a place,
where an organism or a species population lives.
For example - a pond is a habitat of zooplankton,
phytoplankton and fish. And the role of an
organism in its environment is called niche.
Niche denotes the working place of an organism.
Habitat can be similler for some organism but
niche is different. For example - a lake is a
habitat of all type of fish whose niche are
diffirent they may be carnivorous, herbivorous or
omnivorous fish depending on their food
habitat.

4. 2. HISTORY :- ● Joseph Grinnel (1917) coined
the word niche to denote the microhabitat,
where the organism lives.
● Charles Elton (1927) regard the niche as the
fundamental unit of an organism.
● Kendeigh (1974) considerd the niche as a
combination of the habitat and biotic intraction
of a species for it’s survival and continuence in a
community.

5. 3. TYPES OF HABITAT :- As we all know, habitat
is a place where the organism live. Habitat may be
divided into many types such as terrestrial, aquatic
etc.
(A) Terrestial :- A terrestial habitat may comprise
forest, grassland, tundra, desert and so on.
(i)Forest habitat :- It is characterised with trees,
mostly above 8 meters. The forest community
may be evergreen, decideous, high and low.

6. (ii)Grassland habitat :- This habitat is consists of
grass and herbaceous plants. The majority of them
being graminoid.
(iii) Desert habitat :- In this habitat mostly
succeulant plants are found. The tempreture of this
region is very high.
(iv) Tundra habitat :- It consists of very low woody
vegitation.

8. (B) Aquatic habitat
(i) Fresh water :- Species found in fresh water
like river, lake,pond etc is called fresh water
species and this type of habitat is called fresh
water habitat.
(ii)Saline water :- Species found in marine water
like ocean,sea is called saline water species and
this type of habitat is called saline water
habitat.

10. 4. Types of niche :- The ecological niche may
have 3 types :-
(A)Spartial/habitat niche :- As the name
indicates the spartia niche is concerned with the
physical space occupied by an organism. It is
broadly related to concept of habitat, but differ
from it in the sense that while different species
may occupy the same habitat and the area is very
large where an organism live. The activities of each
organism may actually be confined to only a small
portion of habitat called microhabitat.

12. (B)Trophic niche :- This refers to a trophic position
(food level) of an organism. For example – in the
Galapagos island in South Africa birds belonging in 3
genera namly Geospiza (ground finches),
Camarhynchus (tree finches), and Certhidia (warbler
finches) are found. All the birds live in same habitat
but differ in their trophic level. The Camarhynchus
(tree finches) has a parrot like beak and feeds on
buds and fruits. And the other two are carnivorous
and feeds on insects of diffirent size.

14. (C) Hypervolume/ Multidimensional niche :-
The concept of hypervolume or multidimentional
niche was developed by Hutchinson 1965. He
recongnised two type of niche :-
(i) Fundamental niche :- The fundamental niche
is the maximum abstractly inhibited
hypervolume, when the species is not
competing with others for its resources.

15. (ii) Realised niche :- An indivisual or a species
normally remains in competition (either
interspecies or interspecies or both) and thus
under biotic constraints only a part of the niche is
realised by the species. This smaller hypervolume
occupied by a species called the realised niche.

17. 5. Niche breadth and overlap :-
(i) Niche breadth :- Niche breadth may refers to the
width of the area. The species that utilised a broad
spectrum of the environment are called habitat
generalists. They usually have high niche breadth
score. Some species are restricted in their
distribution and live in a narrow range of
environmental spectrum. They exibits low niche
breadth score.

18. Niche breadth of each species can be calculated
using Levine’s formula (1967) :-
1/Bj = € P2 ij
Where :- Bj = niche breadth of species
j and P ij = proportion of occurance of species
j in plot i

20. (ii) Niche overlap :- Niche overlap is a measure of
the association of two or more species. In other
words, how often any two species occured together
in a habitat or ecosystem. A high niche overlap value
of two species indicates that they are found together
more often than other species in a particular habitat.
This indicates their similler habitat requirment and
may also indicate competition if trophic or spartial
niche is same food or space is limiting.

21. Horn’s (1966) formula can be used to calculate
niche overlap score of each species :-
Ljk = 2€ Pij Pik/ (€P2 ij + €P2 ik)
Where :- P ij = Population of occurance of species ‘j’
in plot ‘i’
L jk = over lap of species,
‘j’ , ‘k’ & P jk = population of occurance of species ‘k’
in plot ‘i’

23. 6. Difference between habitat & niche :-

24. 7. Concepts & principals :-
(i) Hypervolume concept :- This concept is based on the
realationship between a species and the environment gradients. For
example :- if we measure the range of environmental temperature
over which a particular species can live and reproduce and do the
same for another gradient like humidity, and then plot this
realationship on graph, we obtain an enclosed space representing
the niche of the species. Since two environmental factors are
considerd

25. the niche is considerd to be two – diamensional. It
will be multi dimesional if more than two
environmental variabels are taken into account.

26. (ii) Gause’s completitive exclusive principal :-
GF Gause (1934) conducted laboratory experiments
on co-existance amoung closely related spicies of
protozoa and on the basis of the result, he concluded
that “no two species with identical niche requirments
can co-exist.” This is defined as if two non
interbreeding species population occupy exactly the
same ecological niche(niche overlap is completed or
near complete) the competition will be so serve that
one species will be lose in the competition and
looser speciesusually exhibits retarded growth and

27. may either leave that niche or become extinct.
(iii) Thomas Park (1948,54) conducted a species
of laboratory experiment on two species of flour
beetle. Tribolium canfusum & T castaneum and
found that when they grow together their survival
depend on environment condition of tempreture
and realated humidity.

28. 8. Conclusion :- A habitat defines the interaction
of organisms with the other factors, which can be
living or non-living, while niche describes how that
specific organism is linked with its physical and
biological environment. Habitat is the part of the
ecosystem, while niche plays an important role in the
formation of an ecosystem.
9. Refrences:-
Fundamental of Ecology – M. C. Dash
Ecology and environment – P. D. Sharma