Unit 1 Ecology and Ecosystem1 (1)

8/19/2019 Unit 1 Ecology and Ecosystem1 (1)

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Unit 1 Ecology and Ecosystem

Environment and its components

Environment- is derived from the french word Environner which means to encircle orsurround. Environment means our surroundings. All the biological and non-biological things

which surrounds an organism are included in environment.

According to Environment (Protection) Act 1986 environment is sum total of water air and

land inter-relationshi! among themselves and also with the human beings other living

organism and !ro!ert".

Types of Environment

#t is of two t"!es

1. Natural Environment- $he natural environmental s"stem o!erates through self

regulating mechanism called homeostatic environment mechanism i.e. an"

change in natural ecos"stem brought about b" natural !rocess is counter

balanced b" changes in other com!onent of the environment.

2. Anthropogenic or Man-made Environment- man is the most !owerful

environmental agent s!earheaded b" modern technologies ca!able of modif"ing

the environment according to his needs to a great e%tent. &an made environment

includes' technolog" trans!ortation industrial revolution dam- building.

Components of Environment

$here are two com!onents of environment

iotic component

A!iotic component

1. iotic com!onent (living com!onent)- the biotic com!onent of environment

consists of flora and fauna including human being as the im!ortant factor. $he

biotic environment includes the living com!onents of the bios!here. or an

organism the biotic factors constitute all the other organisms with which it comes

into regular contact.#f the relationshi! e%ists between organisms of the same s!ecies it is *nown as

intras!ecific relationshi! or intras!ecific association while if it ta*es !lace between

organisms of different s!ecies it is called interes!ecific relationshi! or inters!ecific

association.

+. Abiotic com!onent (non-living com!onent)- includes all non-living factors. $his

includes water air (atmos!here altitude !ressure wind air currents and

humidit") soil tem!erature light to!ogra!h" etc. ,ithos!here h"dros!here and

atmos!here comes under abiotic com!onent.

limatic factors- which include atmos!here light tem!erature humidit" etc.Eda!hic factors- which com!rise lithos!here or soil.


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Lithosphere

Biosphere

Atmosphere

Hydrosphere

Lithosphere

Biosphere

Atmosphere

Hydrosphere

$o!ogra!hic factors- which consist of altitude direction of mountain chains !lains

la*es rivers sea level and valle"s etc."egments of Environment$here are four segments of atmos!here

1. Atmos!here+. ,ithos!here. /"dros!here0. ios!here

All four segments are interconnected to each other. Above schematic shows the

interrelationshi! between all the four segments of environment. $he circle re!resents the

s!here and arrows the flow !athwa"s of matter. &atter ma" flow from one segment to

another in both directions the matter ma" also flow within a given com!artment from

!h"sical location to another without leaving the s!here.

1. Atmosphere- the blan*et of air that surrounds earth is *nown as the

atmos!here. r

$he cover of air that envelo!es the earth is *nown as the atmos!here.

Atmos!here consists of man" gases. $he com!osition of earth2s atmos!here is shown in

following table


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3. 4o. 5as elative !ercentage

1 4itrogen 78.8

+ %"gen +.9

Argon .9

0 arbon :io%ide . 4eon .18

6 /elium .+

7 &ethane .1

8 ;r"!ton .1

9 /"drogen .

1 4itrous o%ide .

11


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• $owards the u!!er levels of tro!os!here the tem!erature decreases u!to

-6. o.

• At the u!!er edge of the tro!os!here is a narrow transition =one *nown as

Tropopause.

2. "tratosphere- above the tro!os!here is the stratos!here.

$his la"er e%tends from an average altitude of 11 to *ilometers above the

earth2s surface.

$his stratos!here contains about 19.9> of the total mass found in the

atmos!here.

• #n the first 9 *ilometers of the stratos!here tem!erature remains constant

with height. A =one with constant tem!erature in the atmos!here is called an

isothermal layer .

• rom an altitude of + to *ms tem!erature increases with an increase in

altitude. $he higher tem!erature is found in this region because of a locali=ed

concentration of o=one gas molecules. $hese molecules absorb ultraviolet

radiations creating heat energ" that warms the stratos!here. $his la"er of

o=one is called o%one layer .

• =one is formed from o%"gen b" a !hotochemical reaction in which energ"

from the sun decom!oses the o%"gen molecule into reactive atomic o%"gen.

• $his o=one la"er !rotects organisms at the earth2s atmos!here from

ultraviolet radiation. ?ithout the o=one la"er life could not e%ist on the earth2s

surface.

Above the stratos!here is a narrow transition =one called strato!ause.

. Mesosphere-

• $his la"er ranges between an altitude of to 8 *ilometers.

• Atmos!here reaches its coldest tem!erature (-9o) at a height of

a!!ro%imatel" 8 *ms from earth surface.

• #t is the la"er where most of the meteors burn u!.

• At the to! of mesos!here is another transition =one called &eso!ause.

&. Thermosphere or 'onosphere

• $his la"er of atmos!here ranges from 8 *ms to *ms above the earth

surface.

• $em!erature increases with height in thermos!here and reaches u!to 1+o.

• #onos!here contains electricall" charged !articles called ions. #t consists of

ioni=ed gaseous com!onents such as +@@ 4@.

• $hese !articles reflect radio waves bac* to the earth surface thus enables us

to have wireless communication.

(. E)osphere


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0

10

20

30

40

50

60

70

80

90

100

-100 -80 -60 -40 -20 0 20

Altitude (Km

!emper"ture(o#

!roposphere

!ropop"use

$tr"tosphere

$tr"top"use

%esosphere

%esop"use

!hermosphere

• $his is the u!!ermost la"er. $his region is also called the outer s!ace.

• $his la"er is e%tended to an altitude of 16 *ms.

• #t contains /@ and /e@@ and has ver" high tem!eratures due to solar

radiations.

2. #ithosphere-


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.+ > as soil moisture.+.> as 3wam! and marshes..06> as ivers.++> iological water

.++> as atmos!heric water.

&. iosphere-

• $his term was first used b" Eduard 3uess.

• #t is com!osed of all living organisms. Plants animals and one celled organisms

are all !art of the bios!here.

• $he life is found from three meters below the ground to thirt" meters above it and in

the to! + meters of the oceans and seas.

• ,iving things form ecological communities based on the !h"sical surroundings of

an area. $hese communities are referred to as biomes. E%am!les of biomes aredeserts grasslands etc.

• #t occu!ies the least volume of all the s!heres but ma%imum flow of matter ta*es

!lace in this segment.

• $he bios!here is res!onsible for the grand scale rec"cling of energ" and matter on

earth.

• Ecos"stems o!erate in this !art of the earth.

Environmental Education

$he s"stematic stud" of environment and our interaction with it is *nown as environmental

science.


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Environmental science is multidisci!linar" in nature. #t deals with all as!ects of life that is

related to us in an" wa". #t is not a single subBect but it has the characteristics of various

disci!lines of life science (botan" =oolog" biochemistr" microbiolog" biotechnolog" and

genetics). #t also interacts with basic science (!h"sics chemistr" mathematics) and some

as!ects of life such as economics management religion laws and social issues.

Environmental science incor!orates information and ideas from multi!le disci!lines. "

combining as!ects of the natural sciences social sciences and the humanities the field of

environmental science can cover more conce!ts and also e%amine !roblems and to!ics from

man" different !oints of view.

Environmental education is the education through environment about the environment

and for the environment. Environmental education has long been defined to include three

critical com!onents' awareness leading to understanding which in turn creates the !otential

and ca!acit" for a!!ro!riate actions. Environmental education includes'

• :evelo!ing !ersonal awareness of the environment and one2s connections to

it.

• :evelo!ing an understanding of environmental conce!ts and *nowledge of

ecological scientific social !olitical and economic s"stems.

•

$he ca!acit" to act res!onsibl" u!on what a !erson feels and *nows in orderto im!lement the best solutions to environmental !roblems.

,!ectives of Environmental Education$he world2s first #nter-governmental onference on Environmental Education was

held in $bilisi 5eorgia. &ost environmental educators have since universall"

ado!ted these obBectives.

• Awareness and sensitivit" about the environment and environmental

challenges.

• ;nowledge and understanding about the environment and environmental

challenges.

• Attitude concern for the environment and hel! to maintain environmentalualit".

')iromet"l


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• 3*ills to mitigate the environmental !roblems.

• Partici!ation for e%ercising e%isting *nowledge and environmental related

!rograms.

'mportance of Environmental Education

Environmental education hel!s in econom" and welfare of human societ".

• #t hel!s us in solving the different issues li*e !ollution measures over

e%!loitation of natural resources food !roblems and sustainable

develo!ment.

• Environmental education hel! hel!s us in finding wa"s to maintain ecological

balance.

• As the industriali=ation is increasing and new technologies are growing to

conserve and !rotect the environment we need ecofriendl" !roduct and

methods it can be achieved onl" through !ro!er *nowledge of environment.

• Environmental education trains us to conserve our fast de!leting natural

resources.

• #t hel!s to understand different food chains and the ecological balance in

nature.

• #t hel!s in encouraging environmental !rotection inculcating attitude and

values and understanding of inter-de!endence of nature and man.

"cope of Environmental Education

• 4atural esources- their conservation and management

•

Ecolog"• iodiversit" and its conservation

• Environmental !ollution and control

• 4atural disasters

• :evelo!ment

• 3ocial issues in relation to develo!ment and environment

• /uman !o!ulation and environment

Ecology and Ecosystem

Ecology- deals with the stud" of relationshi! between organisms and between the organism

and the environment is *nown as ecolog".

Ecosystem- $he term ecos"stem was !ro!osed b" A.5. $ansle" in 19.

#t includes a grou! of biotic communities of s!ecies interacting with one another in an area

and their surroundings in which the" interact with each other and e%change energ" and

matter.

or

Ecos"stem is a d"namic entit" com!osed of a biological communit" and its associated

abiotic environment.

$he !art of the earth where these ecos"stems o!erate is called the iosphere.


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Autotroph Her.i)ore #"ri)ore !op #"ri)ore /e*omposers

"tructure of an ecosystem

Ecos"stem

Abiotic om!onent iotic om!onent

limatic Eda!hic Producers onsumers :ecom!osers

Primar"

3econdar"

$ertiar"

$he functional unit of the ecos"stem consists of two distinct structural com!onents or factors

namel" biotic and abiotic com!onents.

Abiotic com!onents or non-living environmental factors are

limatic factors- it is the weather characteristic of a given !lace which de!ends on

various factors li*e tem!erature light humidit" wind velocit" and atmos!heric gases

etc.

Eda!hic factors- it includes chemical and !h"sical characteristics of the soil.

$he !iotic component of an ecos"stem consists of all living com!onents of the environment

such as !lants animals human beings and microbes. All living organisms of our

environment can be further categori=ed de!ending on their self- food !roducing ca!abilit".

$he" can be categori=ed as autotro!hic com!onent or !roducers and heterotro!hic

com!onent or consumers.

Producer Primar" consumer 3econdar" consumer $ertiar" consumer

Autotro!hic com!onent or Producer- includes all those organisms li*e green !lants

bacteria and algae which contain chloro!h"ll and are ca!able of converting solar

energ" into chemical energ" and storing foodstuff in the !resence of + and /+.6+@ 6/+ 6/1+6@6+

/eterotro!hic com!onent or consumer- organisms which cannot convert solar

energ" into food and de!end on autotro!hs to obtain their energ" for survival are

called consumers or heterotro!hs. /eterotro!hs utili=e rearrange and decom!ose

the com!le% material !roduced b" autotro!hs. :e!ending u!on their feeding habits

the heterotro!hs are classified as follows'


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Primar" consumers- organisms or animals which feed on green !lants to obtain

energ" for survival are called !rimar" consumers or herbivores. E%am!le cows goat.

3econdar" consumers- animals which feed on herbivores are *nown as secondar"

consumers. E%am!le frog li=ards.

$ertiar" consumers- are those that eat the flesh of secondar" consumers. E%am!le

tiger lion vultures. 3ince the" are not *illed and eaten b" other animals the" are

*nown as to! carnivores.

:ecom!osers or sa!ro!h"tes- Plants and animals su!!l" organic matter to the soil

s"stem though shed tissues and death. onsumer organisms that feed on this

organic matter are *nown as decom!osers. :ecom!osers !la" the vital role of

releasing essential materials from the dead organic matter or the !lant therb"

maintaining a continuous c"cle of materials.

$"!es of ecos"stem

Natural EcosystemMarine ecosystem- all the saline water reservoirs on earth such as the seas

oceans and estuaries with their characteristic biome form the marine ecos"stem.resh/ater ecosystem- !onds strems rives and la*es along with their flora and

fauna form the freshwater ecos"stem.Terrestrial ecosystem- it includes desert ecos"stem grassland ecos"stem tree

ecos"stem cro! fields forest ecos"stem and so on.

Man- engineered Ecosystem-

Agriculture and auaculture s"stems are man-engineered ecos"stems. $hese ecos"stems

have all the essential com!onents such as !roducers consumers decom!osers and abiotic

materials. $his is a monoculture s"stem as a single cro! is grown.

4atural ecos"stems are !ol"cultural s"stems and therefore the" are more stable com!ared

to man-made ecos"stems which are fragile and highl" !roductive and generate lots of

!ollutants.

ood chain Cis the seuence of who eats whom in a biological communit" to obtain

nutrients.

or

$he seuential inter-lin*ing of organisms involving the transfer of food energ" from the

!roducers through a series of organisms with re!eated eating and being eaten is referred to

as the food chain. A food chain is alwa"s straight and !roceeds in a !rogressive straight line.

$"!es of food chain

1. 0ra%ing food chain- it starts from green !lants and goes from herbivores to

carnivores and so on. E%am!le

5rass #nsects rog 3na*e Eagle


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2. etritus food chain- the dead organic matter of !lant and animal is called

detritus. &an" animals such as !roto=oas nematodes insects etc. eat detritus

hence the" are called deterivores. $he chain !roceeds to :etritus :eterivores

arnivores and $o! arnivores.

:etritus :eterivores arnivores $o! arnivores

*. arasitic food chain- the" also start from green !lants and then herbivores then

!roceeds to !arasites and finall" h"!er!arasites. $he" !rocess from larger to

smaller organisms.5reen Plants /erbivores Parasites /"!er!arasites

ood 3e!- is a networ* of food chains which become interconnected at various tro!hiclevels so as to form a number of feeding connections amongst different organisms of a biotic

communit". $hese are never straight.


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Energ" and nutrient flow in an ecos"stem

oth energ" and nutrients are !assed along a food chain. ?hile energ" is eventuall" lost to

heat nutrients are constantl" being rec"cled.

3unlight is converted into energ" as glucose b" a !rocess called !hotos"nthesis and stored

in !lants. As first level consumers eat !lants this stored energ" is transferred through

carbon-carbon bonds which release energ" when the" are bro*en. :uring res!iration the

bonds are bro*en and carbon combines with o%"gen to form carbon dio%ide. $he energ" that

is released is used b" the organism or is lost as heat. Dltimatel" all energ" in a food chain

returns to the s"stem as heat. n an average about 1> of net energ" !roduction at one

tro!hic level is !assed on to the ne%t level. Processes that reduce the energ" transferred

between tro!hic levels include res!iration growth and re!roduction defection and non-

!redator" death.

!lant -- eaten b" animal -- carboh"drates digested into glucose -- res!iration -- energ"

for cell !rocesses

3ome of the carboh"drates digested into glucose will be converted into other substances

such as fats.

$he other com!onent that travels through a food chain is inorganic nutrients which do not

contain carbon-carbon bonding. $hese include !hos!horous cellular membranes nitrogen

and iron. $he movement of these substances comes from an inorganic nutrient !ool usuall"

the soil or water surrounding !lants or algae. $he" are absorbed b" the !lants and !assed

from organism to organism as the" are consumed. ?hen the organism dies the nutrientsare rec"cled as the" are decom!osed and become available for !lants as the c"cle

continues.

Energ" flow is unidirectional whereas nutrient flow is c"clic.

Ecological pyramid- an ecological !"ramid ma" be defined as gra!hical re!resentation of

tro!hic structure and function of an ecos"stem i.e. these are the gra!hical re!resentation of

the numbers or biomass or status of accumulated energ" at different tro!hic levels in a food

chain in an ecos"stem. Ecological !"ramids begin with !roducers on the bottom (such as

!lants) and !roceed through the various tro!hic levels (such as herbivores that eat !lants

then carnivores that eat herbivores then carnivores that eat those carnivores and so on).$he" can be u!right and inverted.

http://en.wikipedia.org/wiki/Autographhttp://en.wikipedia.org/wiki/Autographhttp://en.wikipedia.org/wiki/Autographhttp://en.wikipedia.org/wiki/Autograph


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"r"sites

Birds

$hese are of three t"!es-

1. P"ramid of number- is a gra!hical re!resentation showing the arrangement of

number of individuals !er unit area at different tro!hic level of a food chain in an

ecos"stem. #t can be u!right or inverted. An auatic ecos"stem is an e%am!le of

u!right !"ramid where the number of organisms becomes fewer and fewer higher u!

in the !"ramid. An inverted !"ramid of numbers is one where the number of

organisms de!ending on the lower levels grows closer toward the a!e%. A !arasitic

food chain is an e%am!le.

D!right !"ramid of number E%am!le- grassland ecos"stem

#nverted !"ramid of number E%am!le- $ree ecos"stem

2. P"ramid of biomass- is a gra!hical re!resentation of biomass (total amount of living

or organic matter in an ecos"stem at an" time) !resent !er unit area in different

tro!hic levels. #t can be u!right or inverted. An u!right !"ramid is one where the

combined weight of !roducers is larger than the combined weight of consumers. Ane%am!le is a forest ecos"stem. An inverted !"ramid is one where the combined

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weight of !roducers is smaller than the combined weight of consumers. An e%am!le

is an auatic ecos"stem.

D!right !"ramid of biomass

E%am!le- orest ecos"stem

#nverted !"ramid of biomassE%am!le- Pond ecos"stem

*. P"ramid of energ"- is a gra!hical re!resentation of amount of energ" !er unit area

!er unit time at different tro!hic levels of a food chain. $his !"ramid is alwa"s u!right

as there is gradual decrease in energ" at successive tro!hic levels.

P"ramid of energ"E%am!le- orest ecos"stem

iogeochemical cycle- the circulation of chemical nutrients li*e carbon o%"gen nitrogen

!hos!horus calcium and water etc. through the biological and !h"sical world are *nown as

biogeochemical c"cles. #n effect the element is rec"cled although in some c"cles there ma"

be !laces (calledreservoirs

) where the element is accumulated or held for a long !eriod oftime.

r

#t is a !athwa" b" which a chemical element or molecule moves through both biotic

(bios!here) and abiotic (lithos!here atmos!here and h"dros!here) com!artments of earth.

A c"cle is a series of change which comes bac* to the starting !oint and which can be

re!eated.

$he term FbiogeochemicalG tells us that biological geological and chemical factors are all

involved.

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http://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Biospherehttp://en.wikipedia.org/wiki/Lithospherehttp://en.wikipedia.org/wiki/Atmospherehttp://en.wikipedia.org/wiki/Atmospherehttp://en.wikipedia.org/wiki/Hydrospherehttp://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Biospherehttp://en.wikipedia.org/wiki/Lithospherehttp://en.wikipedia.org/wiki/Atmospherehttp://en.wikipedia.org/wiki/Hydrospherehttp://en.wikipedia.org/wiki/Earth


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1. Car!on Cycle

arbon is an element. #t is !art of oceansair roc*s soil and all living things. arbon doesn2tsta" in one !lace.

• Car!on moves from the atmosphere to plants.

#n the atmos!here carbon is attached to o%"gen in a gas called carbondio%ide (+). ?ith the hel! of the 3un through the !rocess of !hotos"nthesiscarbon dio%ide is !ulled from the air to ma*e !lant food from carbon.

• Car!on moves from plants to animals.

$hrough food chains the carbon that is in !lants moves to the animals that eat them. Animals that eat other animals get the carbon from their food too.

• Car!on moves from plants and animals to the ground.

?hen !lants and animals die their bodies wood and leaves deca" bringing thecarbon into the ground. 3ome become buried miles underground and will becomefossil fuels in millions and millions of "ears.

+. Nitrogen cycle

http://www.windows2universe.org/earth/geology/periodic_table.htmlhttp://www.windows2universe.org/earth/geology/periodic_table.htmlhttp://www.windows2universe.org/earth/Water/ocean.htmlhttp://www.windows2universe.org/earth/Atmosphere/overview.htmlhttp://www.windows2universe.org/earth/Atmosphere/overview.htmlhttp://www.windows2universe.org/earth/geology/rocks_intro.htmlhttp://www.windows2universe.org/earth/geology/rocks_intro.htmlhttp://www.windows2universe.org/earth/Life/life.htmlhttp://www.windows2universe.org/earth/Life/life.htmlhttp://www.windows2universe.org/physical_science/chemistry/carbon_dioxide.htmlhttp://www.windows2universe.org/physical_science/chemistry/carbon_dioxide.htmlhttp://www.windows2universe.org/earth/Life/plantae.htmlhttp://www.windows2universe.org/earth/Life/animalia.htmlhttp://www.windows2universe.org/earth/geology/periodic_table.htmlhttp://www.windows2universe.org/earth/Water/ocean.htmlhttp://www.windows2universe.org/earth/Atmosphere/overview.htmlhttp://www.windows2universe.org/earth/geology/rocks_intro.htmlhttp://www.windows2universe.org/earth/Life/life.htmlhttp://www.windows2universe.org/physical_science/chemistry/carbon_dioxide.htmlhttp://www.windows2universe.org/physical_science/chemistry/carbon_dioxide.htmlhttp://www.windows2universe.org/earth/Life/plantae.htmlhttp://www.windows2universe.org/earth/Life/animalia.html


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$he nitrogen c"cle is the !rocess b" which nitrogen is converted between its various

chemical forms. $his transformation can be carried out through both biological and !h"sical

!rocesses.

#m!ortant !rocesses in the nitrogen c"cle include fi%ation ammonification nitrification and denitrification.

• 4itrogen is inert and cannot be directl" utili=ed b" most of the living organisms. $he

conversion of nitrogen (4+) from the atmos!here into a form readil" available to

!lants and hence to animals is an im!ortant ste! in the nitrogen c"cle which

distributes the su!!l" of this essential nutrient.

• $he elemental nitrogen is converted into usable forms b" the !rocess of nitrogen

fi%ation and added to the soil.

• 4itrogen fi%ation is !ossible b" the activit" of lightening and nitrogen fi%ing bacteria.

• Plants obtain their nitrogen su!!l" from the soil and convert them into essential

biomolecules. Animals obtain their nitrogen reuirements from !lants.

• After the death of !lants and animals nitrogen com!ounds again reach to the soil.

• $he nitrogenous organic com!ounds in the soil undergo microbial decom!osition b"

the !rocess of ammonification and nitrification.

• $he com!ounds are again absorbed b" the !lant root or get converted into free

nitrogen through denitrification !rocess.

• $he conversion of ammonia to nitrites is !erformed b" nitrosomonas bacteria. ?hile

other bacterial s!ecies such as nitrobacter are res!onsible for the o%idation of

nitrites into nitrates.

• 4itrates are reduced bac* to nitrogen gas b" the !rocess of denitrification. $his

!rocess is !erformed b" bacterial s!ecies such as !seudomonas.

http://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Nitrogen_fixationhttp://en.wikipedia.org/wiki/Nitrogen_fixationhttp://en.wikipedia.org/wiki/Ammonificationhttp://en.wikipedia.org/wiki/Ammonificationhttp://en.wikipedia.org/wiki/Nitrificationhttp://en.wikipedia.org/wiki/Nitrificationhttp://en.wikipedia.org/wiki/Nitrificationhttp://en.wikipedia.org/wiki/Denitrificationhttp://en.wikipedia.org/wiki/Denitrificationhttp://en.wikipedia.org/wiki/Denitrificationhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Nitrogen_fixationhttp://en.wikipedia.org/wiki/Ammonificationhttp://en.wikipedia.org/wiki/Nitrificationhttp://en.wikipedia.org/wiki/Denitrification


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3ater cycle

• ?ater from the trans!iring !lants oceans rivers and la*es eva!orates into theatmos!here.

• $hese water va!ours cool and condense to form clouds and water.

• ?ater !reci!itates bac* as rain and snow to the earth.

,)ygen cycle

• $he o%"gen c"cle is the c"cle that hel!s move o%"gen through the three main regions

of the Earth the Atmos!here the ios!here and the ,ithos!here.

• $he Atmos!here is the region of gases that lies above the Earth2s surface and it is

one of the largest reservoirs of free o%"gen on earth.

• $he ios!here is the sum of all the Earth2s ecos"stems. $his also has some free

o%"gen !roduced from !hotos"nthesis and other life !rocesses.

• #n the bios!here the main c"cles are res!iration and !hotos"nthesis. es!iration is

when animals and humans breathe consuming o%"gen to be used in metabolic

!rocess and e%haling carbon dio%ide. Photos"nthesis is the reverse of this !rocess

and is mainl" done b" !lants and !lan*ton.

• $he largest reservoir of o%"gen is the lithos!here. &ost of this o%"gen is not on its

own or free moving but !art of chemical com!ounds such as silicates and o%ides.

&ost of the time the !rocess is automatic all it ta*es is a !ure form of an element

coming in contact with o%"gen such as what ha!!ens when iron rusts. A !ortion of

o%"gen is freed b" chemical weathering. ?hen a o%"gen bearing mineral is e%!osed

to the elements a chemical reaction occurs that wears it down and in the !rocess

!roduces free o%"gen.

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UNCE 4$he United Nations Conference on Environment and evelopment 15627-

$he 197+ D4 3toc*holm onference focused international attention on environmental

issues es!eciall" those relating to environmental degradation and Htransboundar" !ollution.H

$he last conce!t was !articularl" im!ortant as it highlighted the fact that !ollution does not

recogni=e !olitical or geogra!hical boundaries but affects countries regions and !eo!le

be"ond its !oint of origin. ver the decades following 3toc*holm this conce!t was

broadened to encom!ass environmental issues that are trul" transnational in sco!e

reuiring concerted action b" all countries and all regions of the world in a universal manner

in order to deal with them effectivel". 3uch im!ortant global environmental !roblems includefor e%am!le all *inds of !ollution climate change the de!letion of the o=one la"er the use

and management of oceans and fresh water resources e%cessive deforestation

desertification and land degradation ha=ardous waste and de!leting biological diversit".

#n the "ears that followed it also came to be recogni=ed that regional or local environmental

!roblems such as e%tensive urbani=ation deforestation desertification and general natural

resource scarcit" can s!read to !ose serious re!ercussions for broader international

securit". or e%am!le the" undermine the economic base and social fabric of wea* and

!oor countries generate or e%acerbate social tensions and conflicts and stimulate greater

flows of refugees. Environmental degradation in diverse !arts of the develo!ing as well asthe develo!ed world can in this wa" affect the !olitical economic and social interests of the

world as a whole.

Earth "ummit 415527- $he United Nations Conference on Environment and

evelopment (UNCE) also *nown as the $io "ummit $io Conference and Earth

"ummit was a maBor Dnited 4ations conference held in io de Ianeiro from Iune to 10

Iune 199+.

3ome 17+ countries were re!resented at io 18 b" their head of state or government. $his

made the Earth 3ummit the largest gathering of state leaders in histor". #n addition some+0 re!resentatives of 45s were !resent and about 17 !eo!le attended a !arallel

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45 J5lobal orum2. Almost 1 on-site Bournalists hel!ed to conve" the 3ummit2s

message around the world. ?ith the involvement of about !eo!le in total the Earth

3ummit was the largest environmental conference ever held.

$he Earth 3ummit resulted in two international agreements two statements of !rinci!lesand an action agenda on worldwide sustainable develo!ment'

• $he onvention on iological :iversit"

• $he ramewor* onvention on limate hange ()

• $he Princi!les for the 3ustainable &anagement of orests

• $he io :eclaration on Environment and :evelo!ment Agenda +1 (the D42s

!rogramme of action from io).

3ignificance' $he io Earth 3ummit was im!ortant in at least three res!ects. $he Earth

3ummit was the first global conference to ta*e !lace in a conte%t of mass activism and

heightened 45 involvement.

$he Earth 3ummit !re!ared the wa" for other larger conferences such as the 199 eiBing

ourth ?orld onference on ?omen which involved 189 governments and some +1

45s. $he second develo!ment was that io !rovided a tem!late for future activist

struggles ensuring that from then onwards maBor conferences and international summits

would be accom!anied b" demonstrations.

$io829 429127- #n +1+ the Dnited 4ations onference on 3ustainable :evelo!ment was

also held in io and is also commonl" called io@+ or io Earth 3ummit +1+. #t too*

!lace in ra=il on +-++ Iune +1+ to mar* the +th anniversar" of the 199+ Dnited 4ations

onference on Environment and :evelo!ment (D4E:) in io de Ianeiro and the 1th

anniversar" of the ++ ?orld 3ummit on 3ustainable :evelo!ment (?33:) in

Iohannesburg.

$he io@+ onference was envisaged as a onference at the highest !ossible level

including /eads of 3tate and 5overnment or other re!resentatives. At the io@+

onference world leaders along with thousands of !artici!ants from governments the

!rivate sector 45s and other grou!s came together to sha!e how we can reduce !overt"

advance social euit" and ensure environmental !rotection on an ever more crowded !lanet

to get to the future we want.

$he onference focus was on two themes' (a) a green econom" in the conte%t of

sustainable develo!ment !overt" eradicationK and (b) the institutional framewor* for

sustainable develo!ment.

$he io@+ have highlighted seven areas which need !riorit" attentionK these include decent

Bobs energ" sustainable cities food securit" and sustainable agriculture water oceans and

disaster readiness.

UNCC-$he United Nations rame/or: Convention on Climate

Change (UNCCC or CCC) is an international environmental treat" negotiated at the

Dnited 4ations onference on Environment and :evelo!ment (D4E:) informall" *nownas the Earth 3ummit held in io de Ianeiro from Iune to 10 199+. $he obBective of the

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treat" is to Hstabili=e greenhouse gas concentrations in the atmos!here at a level that would

!revent dangerous anthro!ogenic interference with the climate s"stem.

$he treat" itself set no binding limits on greenhouse gas emissions for individual countries

and contains no enforcement mechanisms. #nstead the treat" !rovides a framewor* for

negotiating s!ecific international treaties (called H!rotocolsH) that ma" set binding limits on

greenhouse gases.

$he D4 was o!ened for signature on &a" 9 199+ after an #ntergovernmental

4egotiating ommittee !roduced the te%t of the ramewor* onvention as a re!ort following

its meeting in 4ew Lor* from A!ril to &a" 9 199+. #t entered into force on &arch +1

1990. As of &a" +11 D4 has 190 !arties.

$he !arties to the convention have met annuall" from 199 in onferences of the Parties

(P) to assess !rogress in dealing with climate change. #n 1997 the ;"oto Protocol wasconcluded and established legall" binding obligations for develo!ed countries to reduce their

greenhouse gas emissions.

ne of the first tas*s set b" the D4 was for signator" nations to establish national

greenhouse gas inventories of greenhouse gas (5/5) emissions and removals.

C- $he Convention on iological iversity (:) entered into force on +9 :ecember

199. $he EarthMs biological resources are vital to humanit"Ms economic and social

develo!ment. As a result there is a growing recognition that biological diversit" is a global

asset of tremendous value to !resent and future generations. At the same time the threat to

s!ecies and ecos"stems has never been so great as it is toda". 3!ecies e%tinction caused

b" human activities continues at an alarming rate.

#n res!onse the Dnited 4ations Environment Programme (D4EP) convened the Ad /oc

?or*ing 5rou! of E%!erts on iological :iversit" in 4ovember 1988 to e%!lore the need for

an international convention on biological diversit". 3oon after in &a" 1989 it established the

Ad /oc ?or*ing 5rou! of $echnical and ,egal E%!erts to !re!are an international legal

instrument for the conservation and sustainable use of biological diversit". $he e%!erts were

to ta*e into account Hthe need to share costs and benefits between develo!ed anddevelo!ing countriesH as well as Hwa"s and means to su!!ort innovation b" local !eo!leH.

" ebruar" 1991 the Ad /oc ?or*ing 5rou! had become *nown as the #ntergovernmental

4egotiating ommittee. #ts wor* culminated on ++ &a" 199+ with the 4airobi onference for

the Ado!tion of the Agreed $e%t of the onvention on iological :iversit". $he onvention

was o!ened for signature on Iune 199+ at the Dnited 4ations onference on Environment

and :evelo!ment (the io HEarth 3ummitH). #t remained o!en for signature until 0 Iune

199 b" which time it had received 168 signatures. $he onvention entered into force on +9

:ecember 199 which was 9 da"s after the th ratification.

$he first session of the onference of the Parties was scheduled for +8 4ovember C 9

:ecember 1990 in the ahamas.

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$he onvention on iological :iversit" was ins!ired b" the world communit"Ms growing

commitment to sustainable develo!ment. #t re!resents a dramatic ste! forward in the

conservation of biological diversit" the sustainable use of its com!onents and the fair and

euitable sharing of benefits arising from the use of genetic resources.

#t has main obBectives'1. $he conservation of biological diversit"

+. $he sustainable use of the com!onents of biological diversit"

. $he fair and euitable sharing of the benefits arising out of the utili=ation of genetic

resources

Documents

Unit 1 Ecology and Ecosystem1 (1)