1. ECOSYSTEM
BIOTIC AND ABIOTIC COMPONENTS

2. ECOSYSTEM
• A region with a specific and recognizable landscape
form, such as a forest, grassland, desert, wetland, or
coastal area
• A community and its physical environment
• The concept of ecosystem was first put forth by A.G
Tansley in 1935
• it can be temporary or permanent, natural or man
made, small or large
• A very small ecosystem is called as microsystem

3. Importance of study
• Gives information about the available essential
minerals and their recycling periods
• Gross and net productivity of the ecosystem are
known
• Provides knowledge about the web of interactions
and interrelations amongst the various populations
as well as the between the population and the
abiotic environment
• Helps humans to know about the conservation of
resources, protection from pollution etc

4. STRUCTURE OF ECOSYTEM
• By structure we mean,
• The composition of biological community including
species, biomass, life history and distribution in
space etc
• Quantity and distribution of non living materials
such as water and nutrients
• Range or gradient of conditions of existence,
temperature, light etc

5. • The structure of the ecosystem means the
components
• The two major components are :-
• Abiotic (non-living ) components
• Biotic (living ) components

6. Abiotic Components
• Abiotic components are the non-living
components of an ecosystem, affecting the life of
organisms.
• Abiotic components can be harmful to the
ecosystem
• Abiotic components are:
– Temperature, light, water, soil, rocks, sulphur,
nitrogen, phosphorous, proteins, lipids,
carbohydrates ,humic substances etc

7. • These specific abiotic factors represent the
geological, geographical, hydrological and
climatological features of a particular
ecosystem

8. WIND
Many plants use the
help of the wind to
disperse seeds over
long distances.
Organisms disperse to
find new habitats rich
in needed resources.
Strong winds can be
very destructive

9. WATER
Water is one of nature’s
most important things is
life. Essential to life, an
organism’s survival
depends an water. Water
is necessary for digestion
and absorption of food;
helps maintain proper
muscle tone-, supplies
oxygen and nutrients to
the cells; rids the body of
water; and serves as a
natural air conditioning
system

10. SUNLIGHT
The sun provides light
and warmth and it is
the energy source for
almost all ecosystems
on Earth. Sunlight
powers
photosynthesis by
plants, the main
producer in most
terrestrial ecosystems

11. TEMPERATURE
Most life exists within a
fairly narrow range of
temperatures, from about
0 C to about 50 C. Few
organisms can maintain an
active metabolism below 0
C for long, and most
organisms’ enzymes are
denatured (they lose their
shape and stop working)
above 50 C. However,
extraordinary adaptations
enable certain species to
live at extreme
temperatures

12. BIOTIC COMPONENT
• The biotic components ranges from extremely
small bacteria, which live in the air, water and soil,
algae which live in fresh and salt water, to the
terrestrial plants which range from grasses and
herbs that grow after the monsoon of every year
to the giant long lived trees of the forest
• The living component of the animal world ranges
from microscopic animals to small insects and
larger animals such as fish, amphibians , reptiles,
birds and mammals

13. • Biotic component is distinguished into
autotrophs , heterotrophs and saprotrophs
• Autotrophs
• Autotrophs are also called producers
• These are photosynthetic plants, generally
chlorophyll bearing, which synthesize high-
energy complex organic compounds (food) from
inorganic raw materials with the help of sunlight,
and the process is referred as photosynthesis.
• Autotrophs form the basis of any biotic system.

14. • In terrestrial ecosystems, the autotrophs are
mainly the rooted plants. In aquatic
ecosystems, floating plants called
phytoplankton and shallow water rooted
plants called macrophytes are the dominant
producers.

15. Heterotrophs
• Heterotrophs are called consumers, which are
generally animals feeding on other organisms
Consumer's also referred as phagotrophs (phago -
to ingest or swallow) or macroconsumers are
mainly herbivores and carnivores
Herbivores are referred as First order consumers
or primary consumers, as they feed directly on
plants . For e.g., Terrestrial ecosystem consumers
like cattle, deer, rabbit, grass hopper, etc.
.

16. • Aquatic ecosystem consumers like protozoans,
crustaceans, etc. Carnivores are animals, which
feed or prey upon other animals
• Primary carnivores or Second order consumers
include the animals which feed on the
herbivorous animals. For e.g., fox, frog,
predatory birds, smaller fishes, snakes, etc.
• Secondary carnivores or Third order consumers
include the animals, which feed on the primary
carnivores. For e.g., wolf, peacock, owl, etc.

17. • Saprotrophs are also called decomposers or
reducers. They break down the complex
organic compounds of dead matter (of plants
and animals).
• Decomposers do not ingest their food.
• Instead they secrete digestive enzymes into
the dead and decaying plant and animal
remains to digest the organic material.
• Enzymes act upon the complex organic
compounds of the dead matter.

20. Types of interactions
• The biotic environment is experienced by an
individual as interactions with other organisms
• These include individuals of the same species (
intraspecific effects) and individuals of many
other species (interspecific effects)

21. Intraspecific relationships
• Reproduction
• One of the first phases is the location of a mate
• This may occur by the advertisement by one
sex of its whereabouts such using scent, light or
sound
• Selection of the mate often includes
competition between individuals of the same
sex , either males for females or rarely females
for males

22. • Care of offspring
• Offspring are usually cared for by their
parents; by the female only or by both parents
• More rarely offspring are cared for by older
siblings. This occurs among colonial insects
such as termites
• Care of offspring includes feeding, guarding,
keeping them warm and transporting
immature individuals

23. • Social behavior
• Many social interactions are altruistic and
centre around finding food and defence
• Guarding and defense of territories, young
and more vulnerable members of the group
are also common in social animals

24. • Competition
• This occurs between individuals within a
species for environmental resources such as
food, space, light, water and mineral nutrients
• Here competition can occur at any time during
the life cycle: between sperm or actively
growing pollen tubes for the chance to fertilize
an egg: between embryos in the womb for
parental nutrients: between seedlings for light
and space:

25. Interspecific relationships
• Reproduction
• Pollination in many angiosperms and a few
gymnosperms involves a more mobile species
as pollen transporter
• Such carriers include insects ,birds, bats and a
few other mammals

26. • Care of offspring
• Care of offspring by another species is rare
• Example- European cuckoos which lay eggs in
the nests of small birds such as the meadow
pipet, hedge sparrow and reed warbler
• The offspring are then reared by the owners of
the nest
• This is a parasitic interaction as the foster
parent usually loses all its own fledglings and
gains nothing

27. • Mutualism
• Where both the organisms gain benefits by
long term association with each other the
relationship is said to be mutualistic
• Often one of the organisms gains food and the
other protection
• Example- trees such as beech, oak and pine
gain amino acids from fungal associations; the
fungi in return receives carbohydrates and
vitamins from the tree

28. • Parasitism and disease
• Parasitism occurs where individuals of one
species live or reproduce using the food and
other resources of an individual of other
species
• The relationships between the parasites and
hosts are many and varied
• Some parasites live within the host-
endoparasites such as gut parasites and other
outside the host- ectoparasites

29. • Predation
• Apart from autotrophs, all organisms have to
feed on other organisms
• Herbivores, insectivores and carnivores are all
involved in interspecific interactions
• Protection
• Many organisms attempting to avoid predation
use other organisms for protection Example-
insects hide under tree bark, birds nest in holes
in plants to protect their young

30. • Some organisms gain protection from predation
by using the defence mechanism of another
species
• Example-The cinnabar moth caterpillar eats the
poisonous ragwort plant and concentrates the
plant’s toxin in its own tissues
• The caterpillars are brightly colored with black
and yellow stripes to warn birds that they are
unpleasant to eat
• Some edible species even copy the warning
colorations of harmful ones to gain protection

31. • Competition
• Competition between the individuals of
different species is probably extremely
important for determining the abundance,
health, reproductive capacity and distribution
of species within a community
• Competition probably occurs between similar
or related species or between quite different
species which need the same resources

32. • Defence
• Organisms respond to predation, parasitism and
competition by using defence mechanisms
• These includes mechanical defences like sharp
spines on cacti (protecting the plant, which
contain a store of water, from thirsty desert
animals), toxins in the ragwort for caterpillar
• Sometimes toxins are produced by plants to kill
other plants in the surrounding vegetation

33. Energy flow in an ecosystem
• A general energy flow scenario follows:
• Solar energy is fixed by the photoautotrophs , called primary
producers, like green plants
• Primary consumers absorb most of the stored energy in the
plant through digestion and transform it into the form of
energy they need, such as adenosine triphosphate (ATP),
through respiration
• A part of the energy received by primary consumers,
herbivores, is converted to body heat (an effect of respiration),
which is radiated away and lost from the system.

34. • The loss of energy through body heat is far
greater in warm-blooded animals, which must
eat much more frequently than those that are
cold-blooded.

35. • Secondary consumers, carnivores, then
consume the primary consumers, although
omnivores also consume primary producers.
• Energy that had been used by the primary
consumers for growth and storage is thus
absorbed into the secondary consumers
through the process of digestion.

36. • As with primary consumers, secondary
consumers convert this energy into a more
suitable form (ATP) during respiration
• Again, some energy is lost from the system,
since energy which the primary consumers
had used for respiration and regulation of
body temperature cannot be utilised by the
secondary consumers

37. • tertiary consumers, which may or may not be
apex predators then consume the secondary
consumers, with some energy passed on and
some lost, as with the lower levels of the food
chain.
• A final link in the food chain are decomposers
which break down the organic matter of the
tertiary consumers (or whichever consumer is
at the top of the chain) and release nutrients
into the soil.

38. • They also break down plants, herbivores and
carnivores that were not eaten by organisms
higher on the food chain, as well as the
undigested food that is excreted by herbivores
and carnivores.
• Saprotrophic bacteria and fungi are
decomposers, and play a pivotal role in the
nitrogen and carbon cycle

39. TYPES
aquatic ecosystem
• It is an ecosystem in a body of water
• Communities of organisms that are dependent
on each other and on their environment live in
aquatic ecosystems. The two main types of
aquatic ecosystems are marine ecosystems
and freshwater ecosystems

40. Marine ecosystems
•cover approximately 71% of the Earth's surface
and contain approximately 97% of the planet's
water.
• They generate 32% of the world's net primary
production
•They are distinguished from freshwater
ecosystems by the presence of dissolved
compounds, especially salts, in the water.
• Approximately 85% of the dissolved materials in
seawater are sodium and chlorine

41. • Marine ecosystems can be divided into many
zones depending upon water depth and
shoreline features.
• The oceanic zone is the vast open part of the
ocean where animals such as whales, sharks,
and tuna live.
• The benthic zone consists of substrates below
water where many invertebrates live

42. • The intertidal zone is the area between high
and low tides
• Other near-shore zones can include
estuaries, salt marshes, coral reefs, lagoons
and mangrove swamps.
• In the deep water, hydrothermal vents may
occur where chemosynthetic sulphur bacteria
form the base of the food web.

43. • freshwater ecosystems
• It cover 0.80% of the Earth's surface and inhabit
0.009% of its total water. They generate nearly 3%
of its net primary production.
• Freshwater ecosystems contain 41% of the world's
known fish species.
• There are three basic types of freshwater
ecosystems:
• Lentic: slow moving water, including pools, ponds,
and lakes.
• Lotic: faster moving water, for example streams and
rivers.
• Wetlands: areas where the soil is saturated or
inundated for at least part of the time.

44. terrestrial ecosystem
• an ecosystem found only on landforms.
• Six primary terrestrial ecosystems exist: tundra, taiga,
temperate deciduous forest, tropical forest, grassland
and desert
•Terrestrial ecosystems are distinguished from aquatic
ecosystems by the lower availability of water and the
consequent importance of water as a limiting factor.
•Terrestrial ecosystems are characterized by greater
temperature fluctuations on both a diurnal and seasonal
basis than occur in aquatic ecosystems in similar
climates.

45. •The availability of light is greater in terrestrial
ecosystems than in aquatic ecosystems because the
atmosphere is more transparent than water.
• Gases are more available in terrestrial ecosystems
than in aquatic ecosystems.
• Those gases include carbon dioxide that serves as a
substrate for photosynthesis, oxygen that serves as a
substrate in aerobic respiration, and nitrogen that
serves as a substrate for nitrogen fixation

46. • Terrestrial ecosystems occupy 28.2%, of Earth's
surface.
• Although they occupy a much smaller portion of
Earth's surface than marine ecosystems,
terrestrial ecosystems have been a major site of
adaptive radiation of both plants and animals.
• Major plant taxa in terrestrial ecosystems are
members of the division Magnoliophyta
(flowering plants), of which there are about
275,000 species, and the division Pinophyta
(conifers), of which there are about 500 species.

47. • Members of the division Bryophyta (mosses
and liverworts), of which there are about
24,000 species, are also important in some
terrestrial ecosystems. Major animal taxa in
terrestrial ecosystems include the classes
Insecta (insects) with about 900,000 species,
Aves (birds) with 8500 species, and Mammalia
(mammals) with approximately 4100 species

48. • forest ecosystem
• A terrestrial unit of living organisms (plants,
animals and microorganisms), all interacting
among themselves and with the environment
(soil, climate, water and light) in which they live.
• The environmental "common denominator" of
that forest ecological community is a tree, who
most faithfully obeys the ecological cycles of
energy, water, carbon and nutrients.

49. • A forest ecosystem has definite boundaries
and includes a forest of trees out to the limit
of tree growth
• There are hundreds of thousands of defined
and undefined ecosystems that can cover the
broadest to the tiniest of areas.
• An ecosystem can be as small as a pond or a
dead tree, or as large as the Earth itself

50. Thank you…………