Ecology

1. Applied Crop Ecology
• The word ecology is derived from Greek word Oikos
meaning house and logos meaning study.
• Ecology is defined as the study of inter-relation
between living organisms and their environment.
Types of Ecology:
(i) Plant ecology: study of plant community plus
environment.
• It is the branch of botany that deals with plant in
relation to their environment.
(ii) Animal ecology: Branch of zoology that deals with
animal in relation to environment

2. History
• Aristotle in 384 B.C. He first time gather information
about the habitat of plant i.e. desert, terrestrial and
aquatic.
• Theophrastus (300 B.C). he is called the Father of
Botany who developed the relation of plants with
particular environment. He wrote much about aquatic
habitat, marine habitat and marshy habitat.
• Linnaeus (1753 A.D). systematic botanist, describe
plants their distribution in relation to the nature of
their habitat. He stayed in INDO-PAK more than 50
years.

3. History
• Al-Beruni (900 A.D). he travelled INDO-PAK area. He
collected much more species and he gain information. He
studied the habitat and habitat of plant growing in this
region.
• He collected about 1700 species place them in groups got
information about their structural changes, Italy, Spain
Greece, France. He get information about nature and
habitat of plant.
• Von Humbolt. He also collected much more information
about plant and correlated the plant distribution on the
earth with that of the prevailing climate. Ecology has
relationship with microbiology, soil science, chemistry,
geology, physiology, biochemistry and many other
branches.

4. Classification of Ecology/ Branches
of Plant ecology
(i) Animal Ecology (ii) Plant ecology
• Plant ecology is further subdivided in autecology
and synecology.
1. Autecology: branch of botany which deals with
single or individual plant with its environment.
• (Auto: self, logy: knowledge) where attention is
concentrated on the individual plant, their life
histories and their relation to the environment factors.
Plant differ in their structure, character and adaptation
e.g. maize and sorghum.

5. Classification of Ecology
• When there is excessive moisture maize get more
benefit than sorghum. In case of shortage of water
116 types of changes occur in sorghum.
• When scientist provide drought conditions to
sorghum, it continue to grow its roots upto 4 ft depth
in search of water but stops the growth.
• Plants differ in character and are markedly different
from each other in their distribution, growth,
adaptation, dispersal, phonological behavior,
regeneration e.t.c
2. Synecology: branch of Botany which deals with the
plant community with its environment.

6. Ecosystem Concept
• Ecosystem is defined by Odum, E.P. (1959) as
“ an area of nature, that includes living
organism and non living substances,
interacting to produce an exchange of matter
b/w the living and non living parts”.
• In the ecosystem non living environment
provides energy, raw materials and space to the
living organism for their growth and
development

7. Component of Ecosystem
• From the structural point of view, unit of terrestrial
ecosystem such as grass land and forest etc. or
aquatic ecosystem such as ponds, lakes etc. has two
main components such as abiotic (non-living) and
biotic (living).
1- Abiotic (Non-living) components:includes basic
elements and compounds of the environment such as
soil, water, grasses, like oxygen, carbon dioxide,
minerals like CO3, PO4 etc. and variety of organic
compounds. It also includes such physical factors,
moisture wind currents and solar radiation, solar energy
is the source of energy for all the ecosystem.

8. Component of Ecosystem
2- Biotic (living) components: is the living component of
the ecosystem, it is further divisible into two main parts i.e.
Auto-trophs or producers and hetero-trophs or consumers.
(i) Autotrophs or producers are able to fix light energy
and manufacture food from simple inorganic substances
they mainly consist of green plants.
(ii) Heterotrophs or consumers are the living organisms
that utilizes, rearranges and decomposes the complex
material synthesized by the producers or autotrophs. In other
words the heterotroph are the organisms that do not produce
their own food but depends upon other autotrophic
organisms for their nourishment.

9. Component of Ecosystem
The heterotrophic component include macro consumer and
micro consumer or decomposers.
• Macro consumer includes large animal. It is further
divided into primary, secondary and tertiary consumers
A. Primary Consumers: they are purely herbivorous
animals.
• They include large animals or macro consumers like
many insects, mouse, rabbits, goat, sheep, deer, birds etc
are the common herbivorous of terrestrial ecosystem
where as protozoa, small molluses, and crustaceans as
well as fishes are herbivores of the aquatic ecosystem.

10. Component of Ecosystem
 Small insect or micro scopic herbivore animals are
called as zooplankton. It includes rotifers, protozoans
and crustaceans. They live only on phytoplankton or
microscopic plants.
(B) Secondary Consumers: includes carnivores or
omnivores. Carnivores are the flesh (meat) eating animals
that get their energy by eating herbivores.
 Carnivores includes some insects and another large
animals like cats, dogs, snakes, fox, eagle etc.
 Some organisms such as ants, crow, sparrow, hen, bear,
and man can derive their energy from both plants as well
as animals. They are known as Omnivores

11. Component of Ecosystem
(c) Tertiary consumers or top consumers: obtained their energy
by preying (attack) upon the herbivores, carnivores as well as
omnivores.
Tertiary consumer lion, tiger, hawk etc.
• Another type of heterotrophs are decomposers or saprophytes.
• They are the micro consumers which are chiefly the Bacteria,
fungi. They breakdown the complex components and proplasm
absorbs some of the decomposition product and release
minerals back into the ecosystem, which once become
available to the producers.
• Without the decomposers dead materials would simply
accumulate and raw materials such as phosphorus, nitrogen
would be held up by the remains of plants and animals. The
decomposers play a very important role in providing cycling
mechanism in the ecosystem.

12. Types of Ecosystem
Natural: these are undisturbed ecosystem which can further be
divided as follows,
1. Aquatic ecosystem of open water which include
• Marine ecosystem: consisting of deep water bodies like ocean
estuaries etc.
• Fresh water ecosystem: consisting of lotic or running fresh
water like stream or rivers and lentic standing water such as
ponds, lake etc.
2. Terrestrial Ecosystem pertaining to forest, grassland, desert
etc.
• Artificial: in these type of ecosystems, natural balance is
being disturbed by man and maintained by him. Artificial
ecosystem consists of manmade forest, orchards, cultivated
field etc.

13. Types of Ecosystem
• Pond ecosystem: A pond as a whole serves a good example
for a fresh water ecosystem, it exhibits a self sufficient, self
regulating system. Basic components of pond ecosystem are
as,
a) Abiotic component: it consists of inorganic and organic
components. Solar radiation is the energy giving force, which
is trapped by the producers. Basic inorganic and organic
compound consists of water CO2, dissolved oxygen, salt of
calcium.
b) Biotic components: (i) producers; these are autotrophic
plants which fix radiant energy and with the help of
chlorophyll, water and mineral, manufacture complex
organic substance like glucose. (ii) suspended filamentous
algae; they are considered as more important producers than
the larger plants.

14. Grassland Ecosystem
Grassland is a type of terrestrial ecosystem. Various
components of Grassland ecosystem are,
I. Abiotic component: it includes aerial as well as soil
environment of the grassland. Plants receive solar
energy of the sun and by the help of CO2 manufacture
food material. From the soil environment water is
absorbed along with other materials (nutrients) such as
CO3, NO3, PO4 and sulphate.
II. Biotic component: (i) producers; mainly grasses and
small herbs.
(ii) carnivores; they occure as primary consumers which
consists of herbivorous insects like grass hopper, millipedes
and other large animals.

15. Grassland Ecosystem
Secondary consumers:
• are the carnivorous animals feeding on the
herbivores. These includes the animal like fox,
snakes, frog, lizard, birds. Sometimes the hawks
also feed on secondary consumers i.e. snakes and
birds. Thus occupying the position of tertiary
consumers in the food chain.
• Decomposers: as in aquatic ecosystem
decomposers in grassland also consist of fungi
and bacteria.

16. Ecosystem Function
• Flow of energy and circulation of material in an
ecosystem is termed as the ecosystem function.
• Energy enters ecosystem at the time of photosynthesis,
flows in a non cyclic manner. It is successively utilized
by producers and consumers in the shape of organic
matter.
• Energy is used once by a given organism or
population. It is converted into heat and soon lost from
the ecosystem. Material such as nitrogen, carbon,
phosphorus e.t.c can circulate many times in a cyclic
manner between living and non living components of
the ecosystem during different types of biogeochemical
cycles.

17. Productivity
• The productivity of different types deals with the rate
at which food is manufactured by producers in unit
area and in unit time.
Types of productivity:
• A- primary productivity of an ecology is the rate at
which solar energy is converted into organic energy
by green plants or in other words.
• It is the total food assimilation rate produces of
producers primary productivity can be measured in
grams. hydrate produced per unit of land surface per
year.

18. Primary Productivity Types
i. Gross primary productivity (G.P.P): is the
total rate of photosynthesis or the total amount
of organic matter fixed including thawt used up
in respiration.
ii. Net primary productivity (N.P.P): is the
organic matter stored in plant tissues excluding
that which is used up in the process of
respiration. N.P.P also represents food available
to the consumer. Both can be calculated by
following formulae as,
• G.P.P = photosynthesis – respiration
• N.P.P = G.P.P – respiration

19. Definition
• B- Secondary productivity: the amount of energy
available to (???????)
• Abiotic factors: characterized by the absence of life,
includes temp., humidity, pH and other physical and
chemical influences.
• Adaptation: a structure, part or characteristics which
aids in the survival of plants or animals under certain
environmental conditions.
• Means by which an organism adapts itself to changed
surroundings.

20. Definition
• Amphibiophytes: emerged plants growing on moist
and swampy banks of river, stream, ponds lakes etc.
• Ectophytes: subspecies or race that is especially
adapted to a prevailing set of environmental
conditions.
• Ecosystem: is defined by Odum, E.P. (1959) as “an
area of nature, that includes living organism and non
living substances, interacting to produce an exchange of
matter b/w the living and non living parts”. In the
ecosystem non living environment provides energy, raw
materials and space to the living organism for their
growth and development.