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ECOLOGY
Chapter 3
WHAT IS ECOLOGY?
Section 3-1
ECOLOGY

Ecology is the study of organisms and their
interaction with the environment.

An organism is any living thing

Examples: Humans, animals, plant, bacteria
ECOLOGY

The Biosphere

The biosphere is the
combined portions of
the planet where life
exists, including land,
air, water, or
atmosphere.

It extends from about 8
kilometers above the
earth’s atmosphere to
about 11 kilometers
below the surface of
the water
LEVELS OF ORGANIZATION

To understand the
relationships within the
biosphere, ecologists ask
questions about events
and organisms that
range in complexity from
a single individual to the
entire population
INDIVIDUAL
 POPULATION
 COMMUNITY
 ECOSYSTEM
 BIOME
 BIOSPHERE

IMPORTANT VOCABULERY

-Species (individual) group of similar organisms can
breed and produce fertile offspring

-Populations- group of individuals of same species that live
in the same area

-Communities- group of populations that live together in a
defined area

-Ecosystem- collection of all organisms in a particular place
includes nonliving or physical environment

-Biome- group of ecosystems that have the same climate
and similar dominate communities

-Biosphere- all portions of living planet
THINK OF A MNMOMIC TO REMEMBER THE LEVELS
B
B
E
C
P
S
WHAT’A YOUR
MNMONIC?
Bad
Boys
Escapes
Community
Prison
Suddenly
B
B
E
C
P
S
BIOLOGICAL METHODS
Regardless
of
the tools they
use, scientists
conduct
modern
ecological
research using
three basic
approaches

1. Observing



2. Experimenting



-What species live
here?
-How many species?
-test hypotheses
-set up experiment in
lab or field
3. Modeling
-make models
 -predictions
 -test further with
observations and
experiments

ENERGY FLOW
Section 3-2
The sun is the main source of energy
for life on earth
 HOWEVER, there are some
organisms that rely on other sources
of energy
 These organisms use energy
stored in inorganic (bonds that do
not contain carbon) chemical
compounds
 A good example of these types
of organisms are those found
deep in the ocean near thermal
vents
 The organisms use the
chemical energy that is
loaded in the water
surrounding the vent

P
R
O
D
U
C
E
R
S
AUTOTROPHS
A
groups of organisms that can use the
energy in sunlight to convert water and
carbon dioxide into Glucose (food)
 Autotrophs are also called Producers
because they produce all of the food that
heterotrophs use
 Without autotrophs, there would be no life
on this planet
 Ex. Plants, Algae, and certain Bacteria
AUTOTROPHS
BREAK DOWN THE WORD
Auto
SELF
-
Troph
FOOD
-
AUTOTROPHS
 Chemotrophs



Autotrophs that get
their energy from
inorganic substances,
such as salt
Live deep down in the
ocean where there is
no sunlight
Ex. Bacteria and
Deep Sea Worms
HOW DO THEY MAKE THEIR OWN FOOD?
PHOTOSYNTHESIS
CHEMOSYNTHESIS
PHOTO – light
 SYNTHESIS – to make
 Harness solar energy to
produce food
 Where?


On land ---plants main
autotrophs
 In water --- upper
layers of water

CHEMO – chemical
 SYNTHESIS – to make
 Harness chemical
energy to produce food
with the absence of light
 Where?
On land – mainly
bacteria in hot springs
 In water – deep ocean
floor volcanic vents

CONSUMERS
 Many
organisms cannot make their own
food. The ONLY way to obtain energy is
from other organisms…….these
organisms are called consumers or
heterotrophs
 Definition- organisms that rely on other
organisms for their energy and food
supply
 HETERO – other
 TROPH - food
HETEROTROPHS
THERE ARE DIFFERENT SUB-TYPES OF CONSUMERS
Herbivores
Omnivores
Carnivores
Detritivores
Decomposers
DIFFERENT SUB-TYPES OF CONSUMERS
 Consumers/heterotrophs

1. Scavengers/Detritivores – feed on the tissue
of dead organisms (both plans and animals)

DETRITIUS- dead matter
VORES – to consume

Ex. – Vultures, Crows, and Shrimp
SUB-TYPES OF CONSUMERS
 Consumers/heterotrophs

2. Herbivores – eat ONLY plants

HERBI – a plant
VORE – to consume

Ex. – Cows, Elephants, Giraffes
SUB-TYPES OF CONSUMERS
 Consumers/heterotrophs

3. Carnivores – eat ONLY meat

CARNI – MEAT
VORE – to consume

Ex. – Lions, Tigers, Sharks
SUB-TYPES OF CONSUMERS
 Consumers/heterotrophs

4. Omnivores – eat BOTH plants and animals

OMNI – all
vore- to consume

Ex. – Bears and Humans
FEEDING RELATIONSHIPS
Energy
flows through
an ecosystem in one
direction from the sun to
producers then to
consumers
TRANSFER OF ENERGY
 When
a zebra eats the grass, it does not
obtain all of the energy the grass has
(much of it is not eaten)
 When
a lion eats a zebra, it does not get
all of the energy from the zebra (much of
it is lost as heat)
TRANSFER OF ENERGY
 The
two (2) previous examples of energy
transfer show that no organism EVER
receives all of the energy from the
organism they just ate
 Only
10% of the energy from one trophic
level is transferred to the next – this is
called the 10% law
TROPHIC LEVELS
 Energy
moves from one organisms to
another when it is eaten
 Each
step in this transfer of energy is
know as a trophic level

The main trophic levels are producers,
consumers, and decomposers
FOOD CHAINS
 The
energy flow from one trophic level to the
other is know as a food chain
 A food chain is simple and direct
 It involves one organism at each trophic level




Primary Consumers – eat autotrophs (producers)
Secondary Consumers – eat the primary consumers
Tertiary Consumers – eat the secondary consumers
Decomposers – bacteria and fungi that break down
dead organisms and recycle the material back into
the environment
FOOD CHAIN
FOOD WEB
 Most
organisms eat more the JUST one
organism
 When
more organism are involved it is
know as a FOOD WEB
 Food
webs are more complex and involve
lots of organisms
FOOD WEB
FOOD WEB
ECOLOGICAL PYRAMIDS
Diagram
that shows the
relative amount of
energy or matter
contained within each
trophic level in a food
chain or food web
ECOLOGICAL PYRAMID
An ecological pyramid
shows the relationship
between consumers
and producers at
different trophic levels
in an ecosystem
(see diagram to right)


The Pyramid shows
which level has the
most energy and the
highest number of
organisms
Three Main Types of Ecological Pyramids
ENERGY
 BIOMASS
 NUMBERS

ENERGY PYRAMID
Only
about 10%
of the energy
available within
one trophic level
is transferred to
organisms at the
next trophic
level
Ecological Pyramid of Energy
ECOLOGICAL PYRAMID of ENERGY
Pyramid of BIOMASS
 The
total mass of the organic matter
(living matter) at each trophic level is
called biomass
 Biomass
is usually expressed in grams per
unit area
 Biomass
is just another term for potential
energy – energy that is to be eaten and
used.
BIOMASS PYRAMID
Pyramid of Numbers
Pyramid of
Numbers
ECOLOGICAL PYRAMID
•
•
•
•
Which
Which
Which
Which
level
level
level
level
has
has
has
has
the
the
the
the
most energy?
most organisms?
least organisms?
least energy?
CYCLES OF MATTER
Section 3-3
CYCLES OF ENERGY
 Unlike
the one way flow of energy,
matter is recycled within and in
between ecosystems
matter
matter
matter
matter
matter
WATER CYCLE
 Organisms
need water for metabolism (all
chemical reactions) Water is necessary for
photosynthesis
 Plants absorb water into their roots
 Animals drink water or consume it in
their food
Evaporation – water changes into gas
 Transpiration – water evaporation from
leaves

STEPS OF THE WATER CYCLE
 1.
Water evaporates from lakes, rivers,
oceans, etc..
 2. Plants give off water in a process called
transpiration
 3. Water condenses in the atmosphere
and falls back to earth in the form of
precipitation
 4. The water runs off back into lakes,
rivers, etc.
 5. The cycle repeats
STEPS OF THE WATER CYCLE

Ways to return water to the environment
1. respiration
 2. excretion (animal wastes)
 3.transpiration (plants)
 4. precipitation

CARBON CYCLE
Carbon is found in the environment as carbon
dioxide
 Carbon dioxide is needed for photosynthesis
 Carbon dioxide is returned to the environment in
3 ways




1. respiration
2. decomposition
3. the burning of fossil fuels.
NITROGEN CYCLE


The atmosphere is 78% nitrogen, 21% oxygen, 1%
other gases
We can't use nitrogen in the air we breath - it
must come from the foods we eat.
NITROGEN CYCLE

Nitrogen compounds are important for 3 major
reasons in humans:
1. Proteins- are necessary for muscle development
and certain chemical reactions (blood clotting)
 2. Enzymes and hormones - control chemical
reactions in your body - digestion, reproduction etc.
 3. Nucleic Acids - carry the traits from one generation
to the next

NITROGEN CYCLE

Nitrogen compounds are placed back in food
chains 2 major ways:

1. Decomposers

2. Nitrogen-fixing bacteria- bacteria on the roots of
certain plants (legumes - peas, beans) take nitrogen
from the air and put it in the soil
PHOSPHORUS CYCLE
 essential
to living organisms
because it forms part of life
sustaining molecules, such as
DNA and RNA
 Where is P found?
 not very common in biosphere
 mostly land, rocks, soil
 as rocks wear down, p is released
 used by marine animals
NUTRIENT CYCLES
Primary productivity- rate which organic matter
is created by producers
 What is the factor that controls primary
productivity?
 limiting nutrient when ecosystem is limited by
single nutrient that is scare or cycles very slowly
 Farmers aware of this and use fertilizers with
nitrogen, phosphate and potassium
 run-off causes nutrient poor oceans to get lots of
nutrient
 algal bloom- disrupts ecosystem

THE END