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Objectives of the study lesson 9 : Students should be able to
1. Understand and explain ecology, photosynthesis respiration, decomposition, food chain &
food web, pollutions, greenhouse effect, El Nino, La Nina and material cycle in nature.
2. Applied ecology knowledge in the different disciplinary fields.
Conclusion Lesson 9
Ecology
Ecology = Oikos (Habitat), Logos (Study of)
Ecology is a sub-discipline of biology, the study of life. The word "ecology" ("Ökologie")
was coined in 1866 by the German scientist Ernst Haeckel (1834–1919). Ancient philosophers of Greece,
including Hippocrates and Aristotle, were among the earliest to record notes and observations on the
natural history of plants and animals. Modern ecology branched out of natural history and matured
into a more rigorous science in the late 19th century. Charles Darwin's evolutionary treatise including
the concept of adaptation, as it was introduced in 1859, is a pivotal cornerstone in modern ecological
theory. Ecology is not synonymous with environment, environmentalism, natural history or
environmental science. It is closely related to physiology, evolutionary biology, genetics and
ethology. An understanding of how biodiversity affects ecological function is an important focus area
in ecological studies. Ecologists seek to explain:
 Life processes and adaptations
 Distribution and abundance of organisms
 The movement of materials and energy through living communities
 The successional development of ecosystems, and
 The abundance and distribution of biodiversity in context of the environment.
Ecology is the scientific study of the relations that living organisms have with respect to each
other and their natural environment. Variables of interest to ecologists include the composition,
distribution, amount (biomass), number, and changing states of organisms within and among
ecosystems. Ecosystems are hierarchical systems that are organized into a graded series of regularly
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interacting and semi-independent parts (e.g., species) that aggregate into higher orders of complex
integrated wholes (e.g., communities). Ecosystems are sustained by the biodiversity within them.
Biodiversity is the full-scale of life and its processes, including genes, species and ecosystems
forming lineages that integrate into a complex and regenerativespatial arrangement of types, forms,
and interactions. Ecosystems create biophysical feedback mechanisms between living (biotic) and
nonliving (abiotic) components of the planet. These feedback loops regulate and sustain local
communities, continental climate systems, and global biogeochemical cycles. The biological
organization of life self-organizes into layers of emergent whole systems that function according to
nonreducible properties called holism. The means that higher order patterns of a whole functional
system, such as an ecosystem, cannot be predicted or understood by a simple summation of the parts.
“New properties emerge because the components interacts, not because the basic nature of the
components is changed.
Developing of Biotic
Atom
Molecule
Organic Substance
Organelle
Cell
Tissue
Organ
Organism
Ecology System Elements
1. Area
2. Environment Structure
3. Function
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Ecology System Functions
1. Energy Transfer
2. Material Transfer
3. Life Control
Ecology
Abiotic Components
1. Inorganic Structures
2. Organic Substances
3. Climate Regime
BioticComponents
1. Autotrophic Organisms
2. Heterotrophic Organisms
BioticStructure
 Producer
 Consumer
- Herbivores
- Carnivores
- Omnivores
- Scavenger
- Detritivores
 Decomposer, Saprotrop
(Ormotroph)
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Photosynthesis
6C02
Carbon dioxide
+
6H20
Water
C6H12O6
Sugar
+
602
Oxygen
Respiration
In respiration, plants (and animals) convert the sugars back into energy for growth and to
energizelife processes (metabolic processes). The chemical equation for respiration shows that the
sugars form photosynthesisare combined with oxygen. Notice that the equation for respiration is the
opposite of that for photosynthesis.
C6H12O6 + 6026C02 + 6H20 + energy
Chemically speaking, the process is similar to the oxidation that occurs as wood is burned,
producing heat. When compounds combine with oxygen, the process is often referred to as
burning.For example, athlete’s burnenergy (sugars) as they exercise. The harder they exercise, the
more sugars they burn so the more oxygen they need. That is why at full speed, they are breathing
very fast. Athletes take up oxygen through their lungs. Plants take up oxygen through the stomata in
their leaves and through their roots.
Again, respiration is the burning of sugars for energy to grow and to do the internal work of
living. It is very important to understand that both plants and animals (including microorganisms)
need oxygen for respiration. This is why overly wet or saturated soils are detrimental to root growth
and function, and the decomposition processes carried out by microorganisms in the soil.
Decomposition
Decomposition (rotting) is the process by which organic material is broken down into simpler forms
of matter. The process in essential for recycling the finite matter that occupies physical space in the
biome. Bodies of living organisms begin to decompose shortly after death. Although no two
organismsdecompose in the same way, they all undergo the same sequential stage of decomposition. The
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sciencewhich studies decomposition is generally referred to as taphonomy from the Greek word
taphos, meaning tomb.
One can differentiate abiotic and biotic decomposition or biodegradation. The former one
means “degradation of substance by chemical or physical processes, e.g. hydrolysis”. The latter one
means “the metabolic breakdown of materials into simpler components by living organisms”, typically by
microorganisms.
Food Chains & Food Webs
A food chain shows how each living thing gets its food. Some animals eat plants and some
animals eat other animals. For example, a simple food chain links the trees & shrubs, the giraffes (that
eat trees & shrubs), and the lions (that eat the giraffes). Each link in this chain is food for the next
link. A food chain always starts with plant life and ends with an animal.
1. Plants are called producers because they are able to use light energy from the Sun to
produce food (sugar) from carbon dioxide and water.
2. Animals cannot make their own food so they must eat plants and/or other animals. They
are called consumers. There are three groups of consumers.
a. Animals that eat ONLY PLANTS are called herbivores (or primary consumers).
b. Animals that eat OTHER ANIMALS are called carnivores.
 carnivores that eat herbivores are called secondary consumers
 carnivores that eat other carnivores are called tertiary consumers
e.g., killer whales in an ocean food web ... phytoplankton → small fishes
→ seals → killer whales
3. Animals and people who eat BOTH animals and plants are called omnivores.
4. Then there are decomposers (bacteria and fungi) which feed on decaying matter.
These decomposers speed up the decaying process that releases mineral salts back into the food chain
for absorption by plants as nutrients.
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In a food chain, energy is passed from one link to another. When a herbivore eats, only a
fraction of the energy (that it gets from the plant food) becomes new body mass; the rest of the energy
is lost as waste or used up by the herbivore to carry out its life processes (e.g., movement, digestion,
reproduction). Therefore, when the herbivore is eaten by a carnivore, it passes only a small amount of
total energy (that it has received) to the carnivore. Of the energy transferred from the herbivore to the
carnivore, some energy will be "wasted" or "used up" by the carnivore. The carnivore then has to eat
many herbivores to get enough energy to grow.
Because of the large amount of energy that is lost at each link, the amount of energy that is
transferred gets lesser and lesser ...
1. The further along the food chain you go, the less food (and hence energy) remains
available.
Energy Pyramid
Energy Pyramid shows many trees & shrubs providing food and energy to giraffes. Note
that as we go up, there are fewer giraffes than trees & shrubs and even fewer lions than giraffes ... as we go
further along a food chain, there are fewer and fewer consumers. In other words, a large mass of
living things at the base is required to support a few at the top ... many herbivores are needed to
support a few carnivores
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2. Most food chains have no more than four or five links.
There cannot be too many links in a single food chain because the animals at the end of
the chain would not get enough food (and hence energy) to stay alive.
Most animals are part of more than one food chain and eat more than one kind of food in
order to meet their food and energy requirements. These interconnected food chains form a food web.
The following is a possible food web:
Note that the arrows are drawn from food source to food consumers ... in other words,
you can substitute the arrows with the words "eaten by"
A change in the size of one population in a food chain will affect other populations.
This interdependence of the populations within a food chain helps to maintain the balance of
plant and animal populations within a community. For example, when there are too many giraffes;
there will be insufficient trees and shrubs for all of them to eat. Many giraffes will starve and die.
Fewer giraffes means more time for the trees and shrubs to grow to maturity and multiply. Fewer
giraffes also means less food is available for the lions to eat and some lions will starve to death. When
there are fewer lions, the giraffe population will increase.
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Water Pollution
Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and ground
water). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies
without adequate treatment to remove harmful compounds. Water pollution affects plants and
organisms living in these bodies of water. In almost all cases the effects in damaging not only to
individuals species and populations, but also to the natural biological communities
Effect - Diseases
- Malaria
- Typhoid (the rainy season)
- Aquatic Life get Destroyed
How to Avoid
- River should not be used for washing clothes or bathing animals in
- Harvesting of rainwater to meet water requirement
- Dams & embankments must be created
- The rivers must not be contaminates
Noise Pollution
Causes of Noise Pollution
Traffic Noise, Air Craft Noise, Noise from Construction & Civil engineering works, Noise
from the Industry, Noise from other sources
Effect of Noise Pollution
- Hearing loss
- High Blood Pressure
- Stress
- Sleep Disturbance
- Color Blindness
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How to Avoid
- The government should ensure the new machines that should be noise proof
- Airports must be away from residential area
- The sound horn symbol is to be in school roads
Land Pollution
Causes of Land Pollution
- Mining & Quarrying
- Sewage Waste
- Household Garbage
- Industrial Waste
Effect of Land Pollution
- The land cannot be construct house
- Man cannot be farming
- Ground water will gels affected
- House hold garbage like putting plastics
Prevention of Land Pollution
- More and more land should be brought under farming
- Trees should be planted every where
- Waste matter should by disposed immediately
- Avoid drilling the land for more underground water
- Avoid using more fertilizers & plastics
Radio Active Pollution
Radiation (Laser – rays, Radio Active Pollution, Causes of Radio Active Pollution
- Nuclear power plants (ex. Neyveli)
- Nuclear weapon
- Disposal of Nuclear waste
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- Uranium mining
Effect of Radio Active Pollution
- The diseases include blood in cough
- Ulcer
- Swelling of bone joints
- Cancer (Lung, Skin, Bone)
- Eye Problems
Visual Pollution
Factors : Color, Line, Texture, Direction
Causes of Visual Pollution
- Social change (Agriculture
- No prevention
- No conservation
- Communication
How to Avoid
- Promoting in conservation
- Environment Control
- Control Economic Growing
Industry)
Greenhouse effect
The greenhouse effect is a process by which thermal radiation from a planetary surface is
absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this
re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere.
As a result, the temperature there is higher than it would be if direct heating by solar radiation were
the only warming mechanism.
Solar radiation at the high frequencies of visible light passes through the atmosphere to warm
the planetary surface, which then emits this energy at the lower frequencies of infrared thermal
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radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the
energy to the surface and lower atmosphere. The mechanism is named after the effect of solar
radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally
different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that
heat is not lost by convection.
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental prerequisite for life on Earth, there
really can be too much of a good thing.
The problems begin when human activities distort and accelerate the natural process by
creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal
temperature.
 Burning natural gas, coal and oil -including gasoline for automobile engines-raises the
level of carbon dioxide in the atmosphere.
 Some farming practices and land-use changes increase the levels of methane and
nitrous oxide.
 Many factories produce long-lasting industrial gases that do not occur naturally, yet
contribute significantly to the enhanced greenhouse effect and "global warming" that is currently
under way.
 Deforestation also contributes to global warming. Trees use carbon dioxide and give off
oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more
forests are logged for timber or cut down to make way for farming, however, there are fewer trees to
perform this critical function.
 Population growth is another factor in global warming, because as more people use
fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to
increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the
atmosphere.
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El Niño and La Niña
El Niño/La Niña-Southern Oscillation, or ENSO, is a quasiperiodicclimate pattern that
occurs across the tropical Pacific Ocean roughly every five years. It is characterized by variations in
the temperature of the surface of the tropical eastern Pacific Ocean warming or cooling known as
El Niño and La Niña respectively and air surface pressurein the tropical western Pacific the Southern
Oscillation. The two variations are coupled: the warm oceanic phase, El Niño, accompanies high air
surface pressure in the western Pacific, while the cold phase, La Niña, accompanies low air surface
pressure in the western Pacific.
Conclusion
- El Niño – (El Nee – nyo) is the warming of water in the Pacific Ocean.
- La Niña (Lah Nee – Nyah) in the cooling of water in the Pacific Ocean.
El Niño Weather
La NiñaWeather
- Rain and flooding along the Pacific coast
- Snow and rain on the west coast
- Warm water disrupts food chain of fish, birds, - Unusually cold weather in Alaska
and sea mammals
- Unusually warm weather in the rest of the USA
- Tornadoes and thunderstorms in southern US - Drought in the southwest
- Fewer than normal hurricanes in the Atlantic
- Higher than normal number of hurricanes in the
Atlantic
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Satellite Image ofEl Niño and La Niña
1902 –
1903
1918 –
1919
1932 –
1933
1953 –
1954
1972 –
1973
1991 –
1992
Year of El Niño
1905 – 1911 –
1906
1912
1923 – 1925 –
1924
1926
1939 – 1941 –
1940
1942
1957 – 1965 –
1958
1966
1976 – 1982 –
1977
1983
1994 – 1997 –
1995
1998
1914 –
1915
1930 –
1931
1951 –
1952
1969 –
1970
1986 –
1987
1904 –
1905
1917 –
1918
1950 –
1951
1970 –
1971
1988 –
1989
Year ofLa Niña
1909 – 1910 –
1910
1911
1924 – 1928 –
1925
1929
1955 – 1956 –
1956
1957
1971 – 1973 –
1972
1974
1995 – 1998 –
1996
1999
1915 –
1916
1938 –
1939
1964 –
1965
1975 –
1976
????
????
Interesting Facts
 El Nino was first discovered hundreds of years ago by fishermen off the coast of Peru.
 El Nino means "Little Boy" and was named after the Christ child, because it usually
starts around Christmas.
 El Nino is officially called ENSO - El Nino Southern Oscillation.
 La Nina means "Little Girl." It is also called El Viejo, which means "old man," or an
ENSO cold event.
 La Nina occurs roughly half as often as El Nino
 El Nino and La Nina are the most powerful phenomenon on the earth and alter the climate
across more than half the planet.
 El Nino may be caused by underwater volcanoes in the Pacific.
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Material Cycles in Nature
Biogeochemical Cycles
In this section, we examine three material cycles of nature: cycles of water, carbon, and
nitrogen--substances central to maintaining life on Earth. The three material cycles consist of the
transfer of chemicals from biological systems to geological systems and are therefore called
biogeochemical cycles. Processes that affect these transfers are biological processes such as
respiration, transpiration, photosynthesis, and decomposition, as well as geological processes such as
weathering, soil formation, and sedimentation. As materials cycle through, we note that the total
quantity (mass) of matter remains the same, and energy that is put in changes to work (often to rearrange
forms of matter) and is eventually lost to the surroundings.
Map of Schematic Material Cycles
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The Map shows several of the cycles that determine the balance between life (biosphere), the
Earth (lithosphere), and air and water (atmosphere and hydrosphere). All of us are familiar with the
water cycle. The major elements cycled in nature are carbon, phosphorus, nitrogen, and sulfur, along
with oxygen which forms part of all the cycles. The diagram includes general material and energy
flows. Nutrients of smaller systems also cycle--with carbon and oxygen being the main components.
Figure 1 shows the interactions between material cycles, energy input and transfers. Various aspects
such as the water cycle, state of the oceans, and the climate are all interrelated and the rate of human
activities disturbs the natural flows of materials and energy. When the rates of the disruptions are
larger than the capacity of the entire system to bounce back, the system begins to shift, affecting all
levels of the ecosystems through local and global changes.
Materials are transferred between the atmosphere, hydrosphere (oceans), lithosphere (land),
and the biosphere. These various "spheres" act as "reservoirs" that keep materials for different
amounts of time, called residence times. Each cycle forms a complicated system and the systems then
interact with each other to produce weather and climate as well as the periodic fluctuations that
maintain the dynamic balance on Earth, including all life. These cycles have evolved to the present
rate over billions of years. Interruptions of these cycles at much larger rates by human endeavors such
as fossil fuel burning produce several of the environmental problems we face.