Ecosystem - Our Environment, Class 10 Science Video Lecture

is the tiger in some ways dependent on
the grass for survival
at the end of this lesson you should be
able to define ecosystem and state the
components of the ecosystem give
examples of manmade and natural
ecosystem describe the importance of
decomposer
in the ecosystem give examples of food
chain and food web create a pyramid of
energy flow a trophic level your friend
why be here is going to keep you company
along the way he's going to ask you
interesting questions which is also
going to hone your Co scholastic skills
let us have a closer look at this
picture of a lake
what all can you see in this picture we
can see different varieties of fishes
some ducks and boats around we can also
see some all-gay in one part of the lake
the lake is filled with water there are
trees around the lake and there is a lot
of sunlight coming in this area is there
any classification you noticed in the
various things that we observed yes we
can classify it into two types living
and nonliving the fish birds all-gay
animals etc are living components
whereas sunlight water soil air etc or
nonliving components the living
components are called biotic components
and the nonliving are called abiotic
components
what will happen if you remove the
abiotic components the biotic or the
living components will not survive
without water air and sunlight
what happens if you remove the different
varieties of fish from the lake the
Fisher's help maintain the ecological
balance of the lake without them the
water will be filled with reeds and
all-gay and our explosive growth can dry
out the lake so there is an interaction
between all the components present in a
particular environment
in this example a complex community of
all the living and non living organisms
are functioning as an ecological unit
interacting with each other the
community of organisms living together
with its nonliving environment
constitutes an ecosystem so an ecosystem
is a biological environment consisting
of all the organisms living in a
particular area as well as all the
nonliving physical components of the
environment interacting with each other
which of these organisms that you see in
the lake can make their own food green
all-gay phytoplankton green grass
flowering plants like water lilies and
Lotus and certain blue-green alga
produce their own food
the organisms that produce organic
compounds like sugar and starch form
inorganic substances by photosynthesis
are called producers
what about the other living organisms
what do they eat
the other organisms such as frogs
tadpoles insects ducks water Birds
varieties of small and big fish turtle
etc cannot produce their own food these
organisms consume the food produced by
the producers or feed on other animals
and are called consumers then there are
other organisms like fungi bacteria who
act as decomposers and help in cleaning
up dead materials
take a look at these two pictures
what is the difference that you observe
here the first picture is that of a
natural lake whereas the second picture
is of an aquarium which is also a
habitat but man-made
how do you set up a man-made ecosystem
like an aquarium we first get a
container filled with clean water so
that the fishes get enough space then
oxygen is provided through an oxygen
pump area term some artificial corals
and stones are used to make a better
home for the fishes some aquatic plants
are added to make the system
self-sufficient and at last fish food is
regularly provided most important is to
clean up the aquarium so that it does
not get dirty
what will happen if the aquarium gets
dirty all the fishes will die so for a
man-made ecosystem we made provisions
for food and cleaning but how does it
happen in a natural lake in a natural
lake the micro organisms such as
bacteria fungi and other decomposers
break down the dead remains and waste
products of organisms these decomposers
break down the complex organic
substances into simple inorganic
substances which go back into the soil
and are used up once more by the plants
in the lake the insects feed on the
plants the small fishes feed on the
insects and the big fishes in turn eat
the small fishes and these big fishes
are eaten by human beings
what do you notice in this picture in
the aquatic ecosystem organisms form a
series feeding on each other this series
of organisms taking part at various
biotic levels is termed as a food chain
how do these aquatic plants produce food
in the first level of the food chain
solar energy is the main source through
which a green plant is able to prepare
food let us again look at each level of
a food chain which forms a trophic level
the autotrophs or the producers are at
the first tropic level they fix up the
solar energy and make it available for
heterotrophs or consumers the herbivores
or the primary consumers come at the
second level some carnival's
are the secondary consumers come at the
third level larger carnival's
or tertiary consumers form the fourth
trophic level can you think of an
example of a food chain in a forest deer
eat grass and lions eat deer let us see
how this energy is transferred through
the various levels of a food chain the
green plants in a terrestrial ecosystem
capture about 1% of the energy of
sunlight that falls on leaves and
convert it into food energy
when green plants are eaten by primary
consumers a great deal of energy is lost
as heat to environment doing work growth
and reproduction only 10 percent of
energy level is turned into its own body
and available for the next level of
consumers in every step energy is lost
in a similar way hence 10-person can be
taken as an average value of organic
matter present in each step which
reaches the next level of consumers
since very little energy is available
for the next level of consumers a food
chain generally consists of only three
or four steps the loss of energy at each
step is so high that very little usable
energy remains after the fourth trophic
level
each organism is generally eaten by two
or more other kinds of organisms on the
other hand each organism eats more than
one organism for example a rat is eaten
by a cat owl or a snake
hence instead of a straight food chain
the relationship can be shown as a
series of balancing relations called as
food web in a food web there are a
generally greater number of individuals
at the lower trophic levels
you