environment main file

8/11/2019 Environment Main File

1/20

1

1

Environmental Science

Air Pollution

Global climate

change

Stratospheric ozone

depletion

Urban air pollution Acid deposition

Outdoor pollutants

Indoor pollutants

Noise

Biodiversity

Depletion

Habitat destruction

Habitat degradation

Extinction

Water Pollution

Sediment

Nutrient

overload Toxic chemicals

Infectious

agents

Oxygen

depletion

Pesticides

Oil spills Excess heat

Major

Environmental

Problems


2/20

Environment

Environment can be defined as our surroundings

Environment has three domains

1. Gaseousair (atmosphere)

2. Liquidwater (hydrosphere)

3. SolidLand

These three domains meet at a common interface on

the surface of the Earth. This interface, a shallow life

bearing layer is the biosphere.


3/20

Atmosphere The earths atmosphere is an envelope of gases

extending upto 2000feet above the normal groundlevel.

The gases includes

1. Nitrogen2. Oxygen

3. Carbon dioxide

4. Carbon mono oxide etc. and lie

amount of water

The atmosphere protects the earth biosphere by

absorbing a electromagnetic radiation & cosmic rays.


4/20

AtmosphereLayers of atmosphere

1. Troposphere: Lower portion of atmosphere iscalled troposphere. Contain gases & little water

vapours.

2. Stratosphere: Layer above troposphere is

Stratosphere. Contain ozone molecules andabsorbs suns ultraviolet radiations.

3. Mesosphere: Contain very little ozone that

absorbs ultraviolet radiations.

4. Thermosphere: Here atmospheric gases such

as oxygen & nitric oxide split into atoms &

absorbs solar radiations.

5. Exosphere: The outer most layer is calledexos here.


5/20

HydrosphereAll types of water resourcesoceans, rivers, lakes,

ponds, polar ice, glaciers, ground water and water

vapours are collectively called hydrosphere.

1. Hydrosphere is an important part of earth's

surface.

2. About 70% of the earths surface covered withwater. Hydrosphere maintains availability of

fresh water to the biosphere through

hydrological cycle.

3. Hydrological cycle or Water cycle includesevaporation of water from all water resources,

then cloud formation, then precipitation, and

rain.


6/20

Portion of different types of water

Ocean 97.390

Rivers & Lakes 00.020

Vapours in atmosphere 00.001

Glaciers & Polar ice 02.010

Underground water & soil

moisture

00.580

Hydrospheric fresh water 02.601


7/20

Biosphere

Life on earth occupies a thin skin extending more than

a few kilometer below and above its surface. This is

commonaly known as Biosphere.

The existence of life on earth is dependent on biosphere

because it contains all the essential life support system for

all the livings.


8/20

The study of the relationship betweenorganisms and between the organisms and

the environment. The structural andfunctional unit of ecology is known asecosystem


9/20

Abiotic components (non living) these includeinorganic and organic components present in theenvironment in inorganic components such as

oxygen, carbon dioxide, water, minerals. Organiccomponents includes protein, carbohydrates, aminoacids etc.

Biotic substances (living) plants and animals termed

as biotic components


10/20

Types of ecosystem

The biosphere includes four major types of habitats

namely Marine ecosystem: All the saline water reservoirs on earth

such as sea, oceans and estuaries with there characteristicbiome for ecosystem.

Freshwater ecosystem: ponds, streams, rivers and lakesalong with there flora and fauna form the freshwaterecosystem.

Terrestrial ecosystem: includes dessert ecosystem,grassland ecosystem, tree ecosystem, crops fields, forest

ecosystem etc. Man-engineered ecosystem: agriculture and aquaculture

systems are man-engineered ecosystem such asproducers, consumers (herbivores and carnivores).


11/20

Functional components of an ecosystem

Biodiversity.

Productivity (primary and secondary).

Food chains and food webs Materials cycling and energy flow

Balance of nature and

Succession and evolution of ecosystems.


12/20

Biodiversity

The diversity of species is the least at the poles andincrease progressively toward the tropics.

Diversity decreases due to stress, both natural andman-made. The greater the diversity, the better is the

ecosystem. There are about 2, 89,100 species of plants and fungi

and 10,53,800 species of animals presently know toscientists.


13/20

Productivity

The rate of primary production depends upon :-

1. Availability of solar energy and

2. Amount of energy expenditure by respiration and othermaintenance processes.

Productivity are of two types

1. Primary productivity

2. Secondary productivity

The rate of food production in unit time on a unit area

is known as productivity. Green plants contain chlorophyll with the help of which they

convert solar energy into chemical energy (carbohydrates) is

the Gross Primary Production (GPP).


14/20

Secondary Productivity

Secondary Productivity is the net quantity of energytransferred and stored in the reproductive and non-reproductive tissues of heterotrophs overs fixed periodof time.

Heterotrophs include all herbivores, carnivores anddecomposer. Since heterotrophs depend uponautotrophs for food, the secondary productivity directly

depends upon primary productivity. Secondary productivity also depends upon temperature,

ecological and physiological factors and also on thebody size of the heterotroph.


15/20

Flow Chart showing movement of food &

energy in a food chain

Plant

Herbivores

Carnivore -1

Carnivore - 2

Decomposed by bacteria

and fungus

Eaten by

Eaten by

Eaten by

After death

Direction of movement of food

From one organism to other


16/20

Food chains and food webs

The food chains in the ecosystem help to maintain:

The biodiversity of nature.

The feeding relationship of nature.

Flow of energy of the ecosystem.

Passage of nutrients from one organism to another.

In the ecosystem number of food chains operate

simultaneously. These food chains are inter-linkedwith one another to form a food web. For example

plant may be food for any herbivore or carnivoroussuch as human beings.


17/20

Materials cycling and energy flow

It is clear from the food chains that the solar energywhich converted by the autotrophs to chemical

energy as carbohydrates, fats and proteins istransferred to herbivores then to differentcarnivores and finally to the decomposer level.

Decomposer ( bacteria, fungi etc. ) break it into asimpler form which is used as nutrients by theautotrophs.


18/20

Materials cycling and energy flow

DecompositionDecomposition Decomposition

Autotrophs herbivores Carnivores

Energy loss inrespiration-----------------Energy utilized

Reflected

IncomingSolar Energy

Energy loss inrespiration-----------------Utilized Energy

Energy loss inrespiration-----------------Utilized Energy


19/20

Natural resources

Renewable resourceslike sunlight cannot be depleted.

Nonrenewable resourceslike oil CAN be depleted.

Resources like timber and clean water are renewable only

if we do not overuse them.Figure 1.1


20/20

Three ethical worldviews

Figure 2.4

environment main file

Documents