Download The Biosphere

Introduction to Ecology
What is Ecology?
Interactions and
Interdependence
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Ecology – field of science that studies the
interactions of organisms and between
organisms and their environment
• “eco-”
“oikos” (Greek)
“house”
• “ology”
“study of”
• Ecology is the study of nature’s houses!
Interactions and
Interdependence
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The largest of these “houses” is the biosphere
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Biosphere – combined portions of the planet in which
all life exists, including land water and air
The biosphere is ~8 km above earth’s surface and ~11
km below ocean’s surface
INTERACTIONS within the biosphere create a
web of INTERDEPENDENCE is created
between organisms and their environment
Levels of Organization
Non-Ecology
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Cell – basic unit of life
Tissue – groups of similar cells
Organs – groups of similar tissues
Organ Systems – groups of organs
with a similar function
Organism – groups of organ systems
that make up an individual
Ecology
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Species – group of similar
organisms that can breed with one
another and produce fertile offspring
Population – group of same species
in the same area
Community – group of different
populations in the same area
Ecosystem – all living and non-living
things in the same area
Biome – group of ecosystems with
similar climates and communities
Biosphere – all biomes put together
Organism
Population
Community
(Giraffe)
(Herd of Giraffes)
(Giraffe, Zebra, Wildebeest, Trees, Grass)
Biosphere
Biome
Ecosystem
(Earth)
(Southeast area of Africa outlined
in yellow)
(Living and Non-living)
Ecological Methods
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Ecologists have three (3) basic
approaches to conducting research:
• Observing
• Ex: Jane Goodall
• Experimentation
• Artificial environment in laboratory or within natural
ecosystem
• Modeling
• Often used to study phenomena that occur over a
long period of time (e.g. global warming)
Ecology
Energy Flow
Producers
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Sunlight is the MAIN source of energy for all
life on Earth
Only plants, some algae, and certain bacteria
can capture energy from the sun and convert it
into a USABLE form of energy
Autotrophs – organisms that capture and
convert the sun’s energy
•
Also called PRODUCERS!
Producers
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Producers use a process
known as
photosynthesis
Light energy is used to
convert carbon dioxide
(CO2) and water (H2O)
into oxygen (O2) and
carbohydrates (C6H12O6)
Carbon Dioxide + Water + Sunlight
Carbohydrates + Oxygen
Producers
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Some autotrophs can produce food without
light by using a process called
chemosynthesis
Chemical energy is used to convert hydrogen
sulfide (H2S), carbon dioxide (CO2), and water
(H2O) into carbohydrates (C6H12O6) and sulfur
compounds (H2SO4)
This usually occurs in remote locations (e.g.
ocean floor and hot springs)
Bacteria are the most common autotrophs that
use chemosynthesis
Producers
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Photosynthesis
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“photo-” means “light”
Uses light for energy
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Chemosynthesis
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“chemo-” means “chemicals”
Uses chemicals for energy
Consumers
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Many organisms cannot use sunlight as
food
• Animals, fungi, some bacteria
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These organisms must consume other
organisms to obtain energy
These organisms are called
heterotrophs
• Also called CONSUMERS!
Consumers
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Five (5) main types of heterotrophs:
1) Herbivore – consumes only plants
2) Carnivore – consumes only animals
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Some scavengers are considered carnivores
3) Omnivore – consumes plants and animals
4) Detritivores – consumes decaying and rotting
material (such as rotting leaves, etc.)
•
Some scavengers are considered detritivores
5) Decomposers – breaks down organic (living)
material
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Finishes the job that scavengers and detritivores start
Feeding Relationships
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Energy flows through an ecosystem in one direction
Sun/ Inorganic
Compounds
Autotrophs
Heterotrophs
Feeding Relationships
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Food Chain –
series of steps in
which organisms
transfer energy by
eating and being
eaten
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Shows one-way
flow of energy in an
ecosystem
Feeding Relationships
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Most feeding relationships are more
complicated than a food chain
Food Web – network of complex
interactions and feeding relationships in
an ecosystem
Marine Food Web
Terrestrial Food Web
Feeding Relationships
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Trophic Levels – steps in the food
chain/web
• Producers – 1st trophic level
• Consumers – 2nd, 3rd, or higher trophic levels
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Each consumer depends on the previous
trophic level
5th Trophic
Level
4th Trophic
Level
5th Trophic
Level
4th Trophic
Level
3rd Trophic
Level
3rd Trophic
Level
2nd Trophic
Level
2nd Trophic
Level
1st
1st Trophic
Level
Trophic
Level
Ecological Pyramids
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Ecological Pyramid – diagram that shows the
relative amount of energy or matter contained
within each trophic level of a food chain/web
3 Types
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Energy Pyramid – shows the relative amount of
energy available at each trophic level
Biomass Pyramid – shows the amount of living
organic material at each trophic level
Pyramid of Numbers – shows the relative number of
individual organisms at each trophic level
Energy Pyramid
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Only part of the energy that is stored at
one trohpic level can be passed to the
next trophic level
• 10% of the energy at one level is transferred
to the next
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Why isn’t ALL the energy transferred to
the next level?
• The other 90% is used by the organism at the
previous level
Energy Pyramid
Light or Chemical
Energy
Biomass Pyramid
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Biomass – total amount of living tissue
within a given trophic level
• Usually expressed in terms of grams of
organic matter per unit area
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Biomass pyramid represents the amount
of potential food available for each
trophic level in an ecosystem
Biomass Pyramid
10 %
10 %
10 %
10 %
Pyramid of Numbers
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Based on the actual number of
individuals at each trophic level
Does not always resemble the shape of
a pyramid
• Ex: tree may be at bottom of “pyramid”
Pyramid of Numbers
Pyramid of Numbers