ECOSYSTEM

1. ECOSYSTEM

2. ECOSYSTEM
An ecosystem is an area that includes all the biotic (living
organisms) parts such as plants and animals and the abiotic
(non-living) such as soil, rocks and climate sharing an
environment.
“An ecosystem is a community of living organisms in conjunction
with the nonliving components of their environment (things like
air, water and mineral soil), interacting as a system. These biotic
and abiotic components are regarded as linked together through
nutrient cycles and energy flows.
As ecosystems are defined by the network of interactions among
organisms, and between organisms and their environment, they
can be of any size but usually encompass specific, limited spaces
(although some scientists say that the entire planet is an
ecosystem).”

3. The ecosystem is the structural and
functional unit of ecology where the living
organisms interact with each other and the
surrounding environment. In other words, an
ecosystem is a chain of interaction between
organisms and their environment. The term
“Ecosystem” was first coined by A.G.Tansley, an
English botanist, in 1935.

4. • Types of Ecosystem
An ecosystem can be as small as an oasis in a desert, or as big
as an ocean, spanning thousands of miles. There are two
types of ecosystem:
• Terrestrial Ecosystem
• Aquatic Ecosystem
• Terrestrial Ecosystems
Terrestrial ecosystems are exclusively land-based ecosystems.
There are different types of terrestrial ecosystems distributed
around various geological zones. They are as follows:
• Forest Ecosystems
• Grassland Ecosystems
• Tundra Ecosystems
• Desert Ecosystem

6. • Forest Ecosystem
A forest ecosystem consists of several plants, animals and
microorganisms that live in coordination with the abiotic factors
of the environment. Forests help in maintaining the temperature
of the earth and are the major carbon sink.
• Grassland Ecosystem
In a grassland ecosystem, the vegetation is dominated by grasses
and herbs. Temperate grasslands, savanna grasslands are some
of the examples of grassland ecosystems.
• Tundra Ecosystem
Tundra ecosystems are devoid of trees and are found in cold
climates or where rainfall is scarce. These are covered with snow
for most of the year. The ecosystem in the Arctic or mountain
tops is tundra type.
• Desert Ecosystem
Deserts are found throughout the world. These are regions with
very little rainfall. The days are hot and the nights are cold.

11. Aquatic Ecosystem
Aquatic ecosystems are ecosystems present in a body of
water. These can be further divided into two types, namely:
• Freshwater Ecosystem
• Marine Ecosystem
• Freshwater Ecosystem
The freshwater ecosystem is an aquatic ecosystem that
includes lakes, ponds, rivers, streams and wetlands. These
have no salt content in contrast with the marine
ecosystem.
• Marine Ecosystem
The marine ecosystem includes seas and oceans. These
have a more substantial salt content and greater
biodiversity in comparison to the freshwater ecosystem.

18. • Structure of the Ecosystem
The structure of an ecosystem is characterised by the
organisation of both biotic and abiotic components. This
includes the distribution of energy in our environment. It
also includes the climatic conditions prevailing in that
particular environment.
The structure of an ecosystem can be split into two main
components, namely:
• Biotic Components
• Abiotic Components
• The biotic and abiotic components are interrelated in
an ecosystem. It is an open system where the energy
and components can flow throughout the boundaries.

20. • Biotic Components
• Biotic components refer to all life in
an ecosystem. Based on nutrition, biotic
components can be categorized into autotrophs,
heterotrophs and saprotrophs (or decomposers).
• Producers include all autotrophs such as plants. They
are called autotrophs as they can produce food
through the process of photosynthesis.
Consequently, all other organisms higher up on the
food chain rely on producers for food.
• Consumers or heterotrophs are organisms that
depend on other organisms for food. Consumers are
further classified into primary consumers, secondary
consumers and tertiary consumers.

21. – Primary consumers are always herbivores that they rely on
producers for food.
– Secondary consumers depend on primary consumers for
energy. They can either be a carnivore or an omnivore.
– Tertiary consumers are organisms that depend on
secondary consumers for food. Tertiary consumers can
also be an omnivore.
– Quaternary consumers are present in some food chains.
These organisms prey on tertiary consumers for energy.
Furthermore, they are usually at the top of a food chain as
they have no natural predators.
• Decomposers include saprophytes such as fungi and
bacteria. They directly thrive on the dead and decaying
organic matter. Decomposers are essential for the
ecosystem as they help in recycling nutrients to be
reused by plants.

24. • Abiotic Components
• Abiotic components are the non-living component of an
ecosystem. It includes air, water, soil, minerals, sunlight,
temperature, nutrients, wind, altitude, turbidity, etc.
• Functions of Ecosystem
The functions of the ecosystem are as follows:
– It regulates the essential ecological processes, supports life
systems and renders stability.
– It is also responsible for the cycling of nutrients between biotic
and abiotic components.
– It maintains a balance among the various trophic levels in the
ecosystem.
– It cycles the minerals through the biosphere.
– The abiotic components help in the synthesis of organic
components that involves the exchange of energy.

25. • Important Ecological Concepts
• 1. Food Chain
The sun is the ultimate source of energy on earth. It provides
the energy required for all plant life. The plants utilize this
energy for the process of photosynthesis, which is used to
synthesis their food.
During this biological process, light energy is converted into
chemical energy and is passed on through successive levels.
The flow of energy from a producer, to a consumer and
eventually, to an apex predator or a detritivore is called the
food chain.
Dead and decaying matter, along with organic debris, is
broken down into its constituents by scavengers. The reducers
then absorb these constituents. After gaining the energy, the
reducers liberate molecules to the environment, which can be
utilized again by the producers.

28. • 2. Ecological Pyramids
• An ecological pyramid is the graphical representation of the number,
energy, and biomass of the successive trophic levels of an ecosystem.
Charles Elton was the first ecologist to describe the ecological pyramid and
its principals in 1927.
• The biomass, number, and energy of organisms ranging from the producer
level to the consumer level are represented in the form of a pyramid;
hence, it is known as the ecological pyramid.
• The base of the ecological pyramid comprises the producers, followed by
primary and secondary consumers. The tertiary consumers hold the apex.
In some food chains, the quaternary consumers are at the very apex of the
food chain.
• The producers generally outnumber the primary consumers and similarly,
the primary consumers outnumber the secondary consumers. And lastly,
apex predators also follow the same trend as the other consumers;
wherein, their numbers are considerably lower than the secondary
consumers.

29. • For example, Grasshoppers feed on crops such as
cotton and wheat, which are plentiful. These
grasshoppers are then preyed upon by common
mice, which are comparatively less in number. The
mice are preyed upon by snakes such as cobras.
Snakes are ultimately preyed on by apex predators
such as the brown snake eagle.
• In essence:
Grasshopper →Mice→ Cobra → Brown Snake Eagle

30. 3. Food Web
Food web is a network of interconnected
food chains. It comprises all the food
chains within a single ecosystem. It helps in
understanding that plants lay the
foundation of all the food chains. In a
marine environment, phytoplankton forms
the primary producer.

33. TROPHIC LEVEL :
The trophic level of an organism is the position it occupies in a
food web. A food chain is a succession of organisms that eat
other organisms and may, in turn, be eaten themselves.
The trophic level of an organism is the number of steps it is from
the start of the chain.
The producers and consumers in the ecosystem can be arranged
into different feeding groups and are known as trophic level or
the feeding level.
• The producers (plants) represent the first trophic level.
• Herbivores (primary consumers) present the second trophic
level.
• Primary carnivores (secondary consumers) represent the third
trophic level
• Top carnivores (tertiary consumers) represent the last level.

35. Meaning Of Pond Ecosystem
Ponds are artificial or natural body of water. Well
ecosystem is technical term for community of organisms.
Pond Ecosystem refers to fresh water ecosystem on which
different organisms depend for their survival and to fulfill
their nutritional needs as well. The ponds are the water
bodies which are usually of 12-15 feet deep in which the
sun rays can reach which results into growing of plants
down there. The components of pond ecosystem include
both biotic and abiotic components. Biotic components
consist of producers, consumers and decomposer
whereas abiotic components include organic and
inorganic materials. It should be noted that biotic
components follow a food chain.

36. Pond ecosystem dependent on each other with the prevailing water
environment for their nutrients and survival.

38. • Types Of Pond Ecosystem
Pond Ecosystem falls in fresh water ecosystem which is further
divided into three parts which are littoral zone, open water zone
and deep water zone. The littoral zone is a zone which is an area
near the shore where sunlight follows it way down and allows
the plants to grow. Open water zone which actually is well
known as pelagic zone. It is that zone where water is not close to
the bottom nor near the shore. The last is the deep water zone
which is the lowest level lying above the sea and below the
thermocline. This three types can be understood deeply. Some
differentiate Pond Ecosystem in other way. It is classified in five
types which are salt ponds, garden ponds, freshwater ponds,
vernal ponds and underground ponds. Salt ponds are one which
are near the sea side and consist brackish water. Garden ponds
are those which are artificial in nature. Freshwater pool can form
anywhere because of rains. Vernal ponds are those which are
created because of depression in the ground and are seasonal.
Lastly underground ponds which are created near the rocks.

39. • Characteristics Of Pond Ecosystem
Pond Ecosystem are the balance of fish, bacteria's and
plants which together support each other. Pond
Ecosystem works on ponds which are shallow enough for
the sunlight to pass through it. It is a living ecosystem
itself. Ponds do not have universally accepted standard of
it’s maximum size. Ponds are wet and are surrounded by
artificial and natural banks. The ponds provide
inhabitation to wetland plant and animals. Pond works
with a combination of three food webs at a time. There
exist a type of pond where no trace of fishes is to be
seen. This type of ponds are known as vernal ponds.
These type of ponds inhabitant rare and endangered
plant species.

40. • Importance Of Pond Ecosystem
Pond Ecosystem has a great significance. They provide
inhabitation to scarce species and support biodiversity much
more then any other freshwater habitat. It is a home to lot many
species. In the midst of landscapes the farmland ponds can
provide us wildlife which is not a small thing. Every pond has a
story to narrate about different people who visit them, be it for
fishing or for soaking cart wheels. Ponds work as mini reservoir
which help to drain fields during rain. Ponds recycle the nutrients
and reduce the amount of nitrates and phosphates. Ponds are
usually man made and are dug for different utilities of mankind.
They provide drinking water during dry weather and vegetation
to animals. They are not just important for quenching thirst or
providing inhabitation but also to add beauty to the mother
nature. It touches our heart and we feel calm and close to
nature.

41. • Conclusion
Ponds are found everywhere but yet they are
endangered so we need to conserve them and
protect them from getting extinct. We need to
remember that we have to save something for
the future generations as well. Ponds are
inhabitation to many and are very important to
maintain the nature.

43. • Equatorial rainforests contain an enormous variety of plants and animals –
approximately 90 per cent of all of the world's species. Vegetation is dense and
occurs in four main layers:
The forest floor/shrub layer. This area is dark as trees block out most of the sunlight.
The forest floor is covered in a thick blanket of dead and decaying roots and leaves,
known as humus. A little vegetation can grow between the trees if it is able to trap
sunlight. This area is prone to flooding during torrential rainfall.
The under canopy is the layer above the forest floor. This area is shady and cooler. As
there is very limited sunlight, seedlings lie dormant until larger plants and trees die.
The gap that is left in the canopy is quickly filled as new plants grow into it. Lianas, or
vines, take root in the ground and climb up trees to reach the sunlight.
The canopy is the continuous layer of tree tops that is more sheltered. The trees are
normally 20 to 40 metres tall. This leafy location with fruit all year round is the habitat
for most wildlife including insects, tree snakes, birds and some mammals, eg howler
monkey, jaguar and sloth.
The emergent layer consists of the tallest trees in the rainforest and they can grow up
to 60 metres. They are higher because they are able to trap more sunlight to help
them make more food to grow. Emergent trees are supported by buttress roots which
prevent them from blowing over in high winds.