Succession in Plants Video Lecture - Biology Class 12 - NEET

hello friends this video on ecosystem
part 19 is brought to you by example
calm no more fear from exam and now
let's talk about ecological succession
that how exactly ecosystems can arise
over a given area over a long period of
time now we will talk about succession
of plants so we will talk specifically
about plants that how do plants have
come up with their new ecosystems so
this is gradual change in the
composition or structure of plants in a
given area over time so maybe in a one
particular area you have a particular
type of plants at certain point of time
now over a long period of time the
variety of plants changed for example
maybe there was one area which was all
covered with grasses now over the long
period of time there were some changes
and now you see huge tall trees over
that area so that means the change in
composition or structure of plants in a
particular area over time is termed as
succession of plants now implants also
succession can be of two types and they
are called xeric succession and highjack
succession now what do we mean by Zarek
and hydric now Zarek is derived from the
word Zarek and Zarek means jenkins
related 0 which means dry whereas hydric
high-drag is derived from the word hydro
which means water so basically in one
succession which we talked about water
that is plants are beings excited over a
long period of time where water plays an
important role and in the other we are
talking about dry region where there is
lack of water so let us try to
understand what is zr and what is
high-drag succession so let us start
with there arc succession so as I had
mentioned before that zarach is derived
from the word Zarek and said it means
dry so these type of succession starts
in the dry areas and that is how they
are related to dry and they're called as
Iraq now what do we mean by that
areas what comes to your mind when you
think of dry areas maybe deserts so in
deserts it is extremely dry there is no
water at all
so in those kind of areas the succession
starts and over a period of time what
happens is it progresses from zarok
conditions to basic conditions now what
do we mean by basic conditions so basic
condition reference to basic means
middle that is intermediate situation
where you do not have complete scarcity
of water but at the same time you do not
have too much of water
so basically zarok is one extreme which
is completely dry and hydric is another
extreme which is completely full of
water so in between these two lies the
music condition so here in there are
fixation what happens is from zarok
condition it gets transformed into music
conditions now how this transformation
take place so it starts from something
like this which is completely zurich
which is completely dry now in dry
conditions do you have lot of plants no
you don't have but you have lichens you
know lichens lichens are the fungal
Association pick the association between
fungi and algae which are present on
rocks so what happens is these like and
start secreting acids and these acids
tend to dissolve the rocks so in dry
conditions you have some rocks like this
and on these rocks you might have
lichens and lichens will secrete some
acids and these rocks will dissolve now
when these rocks start dissolving what
happens there are a lot of minerals and
small substances inside the rocks when
it dissolves it leads to the formation
of soil so small amount of soil
formation start taking place so when you
have small amount of soil formation then
what happens with that small amount of
soil formation small amount of
bryophytes or small plants called
bryophytes start to grow
so soil formation takes place now this
soil formation is followed by small
Times called bryophytes now these brow
files later grow up to form bigger
plants and gradually your soil also
strengthened after how the soil
formation happened when the rocks break
and how the rock breaks breaks or
dissolves whatever you call it and how
they dissolve because of the lichens
which are present on the rocks
now these bigger plants and gradually
what do you see gradually this zarok
community got transformed into a forest
community so this forest community what
will you call it will you call it hybrid
no will you call it Zurich no so it is
basically music conditions that means
intermediate it has water but not too
much of water at the same time it is not
very dry so it is in between the two so
a forest community established from a
Zurich community or from a dry community
so this type of succession over a period
of time is known as there are succession
so zero fighting habitat turned into a
mean so fighting habitat so now we will
talk about the next type of succession
in plant that is high drag succession so
high drag is derived from water so let
us see what happens here so this type of
succession starts in wet areas so it
starts in areas which has too much of
water may be a pond maybe a swamp may be
a lake so they have too much abundance
of water so it starts from those kind of
areas and what happens it progresses
from hydrant to mazing condition so now
you know what is hydric and what is
missing so in the previous slide we saw
from Zarek to mezack but here we will
see how it gets transformed from hydric
to Masek over a period of time so this
is your hydro or hydro phytic habit
so in this habitat what do you have you
have the producers that is the
phytoplankton so earlier you have this
phytoplankton so here you can see them
so these phytoplankton are like plants
they act as producers and aquatic
ecosystem so these phytoplankton were
also known as drifted because they were
capable of drifting through the water
now gradually over a period of time from
these phytoplankton scheme up the rooted
submerged plants so you see here these
are the rooted submerged plants so they
are rooted at the base but they were
floating on the surface so these kinds
of this kind of plants came to exist
after this came up the free-floating
plants so these are free-floating plants
so as you see here so they float freely
on the surface of water so if you look
at Ed you see that phytoplankton were
present inside the water so they were
not present on the surface after that
came up the rooted submerged blanch so
these where the rooted submerged plants
which were rooted deep inside but still
they were visible on the surface also
then came up freely floating plants
which were completely on the surface of
the water which was then followed by
climbs like swamps or scrub like swamps
swamps which are on the surface and they
are not completely on water they are on
those kind of areas which has more water
than soil so then came up the swamps all
and then gradually came up the scrubs
that is the smaller trees they were not
too small but they were not too big and
from the scrubs came up them trees so
gradually you see from deep inside the
water the trees started emerging towards
the surface and gradually they got
transformed from our hydric habitats
towards our music habitat grameen so
fighting habitat so this is how you see
a water body gots gets converted into a
land so this was some water but maybe a
pond or a lake or whatever and this
water body over a period of time got
transformed into a forest community
kind of a structure or a land so water
body gets converted into land and this
type of succession is known as Hydra
succession so in thank you please visit
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