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You Need to know
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Definition of Ecology
Definition of Biosphere
Definition of Ecosystem
Definition of Habitat
Be able to list 5 types of ecosystems
Environmental factors affecting organisms.
1.
Abiotic factors are non living factors
2.
Biotic factors are living factors
3.
Climatic factors refer to weather over a long
period of time.
4.
Edaphic factors relate to soil (soil pH, soil
type, moisture, air and mineral content)
Abiotic Factors
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Steepness
Altitude
Current
Aspect
Exposure
Steepness and Altitude
Currents
Biotic Factors
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Food
Competition
Predation
Parasitism
Pollination and seed dispersal
Humans
Climatic Factors
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Temperature
Rainfall
Humidity
Day Length
Light Intensity
Wind
Salinity
Edaphic Factors
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Soil pH
Organic Matter
Water Content
Air Content
Mineral Content
Soil Type
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Sand
Clay
Where do we get our energy from?
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The sun is the primary source of
energy for our planet.
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Feeding allows energy to flow from
one organism to another in an
ecosystem.
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Producers are organisms that carry
out photosynthesis.
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Consumers are organisms that take in
food from another organism.
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3 types of consumers
 Primary consumers feed on producers
 Secondary consumers feed on primary consumers
 Tertiary consumers feed on secondary consumers
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A grazing food chain is a sequence of
organisms in which each one is eaten by
the next member in the chain.
Grass
Rabbit
Fox
A food web consists of two or more
interlinked food chains.
Sparrow Hawk
Blue Tit
Badger
Thrush
Caterpillar
Slug
Dock leaves
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A pyramid of numbers represents
the number of organisms at each
stage in a food chain.
Fox
Rabbit
Grass
Niche
The ecological niche of an organism is the
functional role it plays in the community.
Each bird in the pictures eats and lives in
different parts of the habitat and hence do not
compete with each other. They have found a niche
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Can you describe the life of a plant?
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Nutrient recycling is the way in
which elements are exchanged
between the living and non-living
components of an ecosystem.
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Elements covered in class are
Carbon and Nitrogen
Carbon Cycle
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Carbon dioxide is removed from the
environment by: Photosynthesis in plants.
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Carbon dioxide is returned to the environment
by:
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2.
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4.
Respiration in plants, animals & micro-organisms.
Decay caused by micro-organisms.
Combustion.
Weathering.
CO2
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Levels have increased from 0.028% to
0.036% over 200yrs
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Main cause is increased combustion of fossil
fuels and deforestation
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Effects of Global Warming
1.
2.
3.
Sea levels rise.
Weather patterns alter
Reverse direction of Gulf Stream
Nitrogen cycle
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All organisms need nitrogen for protein, DNA &
RNA
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80% of the air is nitrogen gas, (Brilliant I can make
as much protein as I want)
However…. it is no use to living things as a gas it
needs to be changed into a chemical compound
called Nitrate NO3
Nitrogen cycle
How does the Nitrogen gas change into Nitrate?
1. Volcanic Action
2. Lightning
3. Industrial Processes
4. Some Bacteria
Nitrogen Fixing Bacteria
N2 gas
ammonia(NH3)
nitrates(NO3).
These bacteria live in the soil or in the roots of
clover, beans and peas (Legumes).
Plants absorb the nitrates made by the bacteria.
In return the bacteria absorbs some of the sugars
made by the plant during photosynthesis.
Hence the plant and bacteria live in Symbiosis
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Animals then eat the Plants and get their nitrogen
from plant protein.
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When organisms die they are decomposed by
Fungi and bacteria which produce Ammonia.
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Then more bacteria (called Nitrifying bacteria)
change this Ammonia into Nitrate. This process is
called Nitrification.
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Plants can then absorb these nitrates.
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Then there are other types of bacteria (called
denitrifying bacteria) that change nitrates into
nitrogen gas. This process is called Denitrification.
Human Impact on Ecosystems
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We are going to look at 3 ways that humans
affect ecosystems:
1. Pollution
2. Conservation
3. Waste Management
Pollution
This is any undesirable change in the environment.
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Can you name any natural pollutants?
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Can you name pollution that arises from human
activity?
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Pollution can affect Air, Freshwater, Sea, Soil and
Land.
Domestic Pollution
Agricultural Pollution
Industrial Pollution