Ecology powerpoint

1. Chapter 3. Ecology!
Honors Biology

2. 3.1 What is Ecology?
Interactions and Interdependence
 Ecology – the scientific
study of interactions
among organisms.
 Biosphere – contains the
combined portions of the
planet in which all life
exists, including land,
water, and air or
atmosphere (8 km above
the Earth’s surface and
11 km below the surface
of the ocean.

3. 3.1 What is Ecology?
Levels of Organization
 Species – a group of organisms
so similar to one another that
they can breed and produce
fertile offspring.
 Populations – groups of
individuals that belong to the
same species and live in the
same area.
 Communities – assemblages of
different populations that live
together in defined area.
 Ecosystem – a collection of all
the organisms that live in a
particular place, together with
their nonliving, or physical,
environment.
 Biomes – a group of ecosystems
that have the same climate and
similar dominant communities.
 The highest level is the
biosphere. Let’s turn to page 100…

4. 3.1 What is Ecology?
Levels of Organization - Review
1.Can a group of
rabbits and a group
of field mice make up
the same population
in an ecosystem?
2. Could a biome in
Brazil near the
equator be the same
biome as a biome in
Northern Canada?
Explain. PG 64

5. 3.1 What is Ecology?
Ecological Methods
 Ecologists use a wide
range of tools and
techniques to study the
living world.
 Observing
 The first step in asking an
ecological question.
 Experimenting
 Used to test hypothesis
 Modeling
 Mathematical formulas
based on data collection,
can be tested further.

6. 3.1 What is Ecology?
Ecological Methods
Ecological Methods
Chemical Testing
Sites
Computer/
Calculators
Written Record
Magnifying Tools
Measuring Tools
Observation Experiment Model Building
Field site Experimental plots,
field sites, laboratory
Many sites for data
collecting
Tapes, compass,
Global Positioning
System, thermometer,
sensors
Tapes, compass,
Global Positioning
System, thermometer,
sensors
Aerial views, Global
Positioning System,
weather balloons
Binoculars, microscope,
telescope
Binoculars, microscope,
telescope
Satellite images
Notes, automated data
storage
Notes, automated data
storage
Automated data storage
Test kits Test kits Large database,
multiple sensors
Mathematical analysis
and graphics, statistics
Mathematical analysis
and graphics, statistics
Mathematical analysis
and graphics, statistics,
simulations

7. Assessment
1. What are the six different major levels of
organization from smallest to largest,
that ecologist commonly study?
2. Is weather a biotic or abiotic factor?
3. Describe the three basic methods of
ecological research.
4. Why is modeling used to describe
ecological phenomenon?

8. Assessment Answers
1. Individual, population, community,
ecosystem, biome, biosphere
2. Abiotic
3. Observation, Experimentation, Modeling
4. Phenomenon- a situation that is observed to
exist or happen whose cause or explanation
is unclear- We use models to try to
understand what is actually going on.
1. Ex. Migration of animals.

9. 3.2 Energy Flow
Producers
 Sunlight is the main energy
source for life on Earth.
 Less than 1% of the sun’s
energy is used by living
organisms
 Some types of organisms rely
on the energy stored in
inorganic chemical
compounds
 Only plants, some algae, and
certain bacteria can capture
energy from sunlight or
chemicals and use that
energy to produce food. They
are called autotrophs.
 Autotrophs are also referred
to producers.

10. 3.2 Energy Flow
Energy From the Sun
 The best known
autotrophs are ones that
use photosynthesis.
 Photosynthesis –
autotrophs that use light
energy to power
chemical reactions that
convert carbon dioxide
and water into oxygen
and energy rich
carbohydrates such as
sugars and starches.
Carbon dioxide + Water Carbohydrates + Oxygen
Light Energy

11. 3.2 Energy Flow
Energy From the Sun
1. Which element does each letter in the formula
stand for?
2. Why are the numbers needed in the
equation?
Carbon dioxide + Water Carbohydrates + Oxygen
Light Energy
6CO2 + 6H20 C6H12O6 + 6O2

12. 3.2 Energy Flow
Life Without Light
 Some autotrophs can
produce food in the
absence of light.
 Chemosynthesis –
when organisms use
chemical energy
 Example. Some
Bacteria.

13. 3.2 Energy Flow
Consumers
 Organisms that rely on other
organisms for their energy and
food supply are called
heterotrophs.
 Heterotrophs are called
consumers.
 There are many types of
heterotrophs:
 Herbivores (eat only plants)
 Carnivores (eat animals)
 Omnivores (eat both plants and
animals)
 Detritivores (feed on plant and
animal remains and other dead
matter)
 Decomposers (break down
organic matter. How can we categorize crabs?

14. 3.2 Energy Flow
Feeding Relationships
 Energy flows through
an ecosystem in one
direction from the
sun or inorganic
compounds to
autotrophs
(producers) and to
various heterotrophs
(consumers)

15. 3.2 Energy Flow
Food Chains
 Food chain – a series of
steps in which
organisms transfer
energy by eating or
being eaten.
 Ex. Prairie: grass being
eaten by an antelope
being eaten by a coyote.
 Ex. Marine: microscopic
algae being eaten by
zooplankton being eaten
by a herring being eaten
by a squid being eaten
by a shark.

16. 3.2 Energy Flow
Food Webs
 In most ecosystems, feeding
relationships are more
complex than a food chain.
 Most producers complete
their life cycles and die, then
decompose.
 Decomposers covert dead
plant matter to detritus, which
are eaten by detritivores.
 When the feeding
relationships among the
various organisms form a
network of complex
interactions, it is described as
a food web.
 Ex. Salt-marsh community

17. 3.2 Energy Flow
Trophic Levels
 Each step in a food
chain or food web is
called a trophic level.
1. Producers
2. Consumers
3. Consumers
4. Consumers
 Each consumer
depends on the trophic
level below it.

18. 3.2 Energy Flow
Ecological Pyramids
 Ecological pyramid – a
diagram that shows the
relative amounts of
energy or matter
contained within each
trophic level in a food
chain or a food web.
 Three types: energy
pyramids, biomass
pyramids, and pyramids
of numbers.

19. 3.2 Energy Flow
Ecological Pyramids
Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent of this
energy for
life processes.
The rest is lost
as heat.
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.
Pyramid of Numbers
Shows the relative
number of individual
organisms at each
trophic level.

20. 3.2 Energy Flow
Ecological Pyramids – Make Connections
The amount of energy available in food is measured in calories. One
calorie is the amount of energy needed to raise the temperature of 1
gram of water 1oc. Scientists usually refer to the energy content of
food in units of kilocalories. One kilocalorie equals 1000 calories. A
kilocalorie is also expressed as a Calorie, with a capital C.
 Suppose, that the base of this energy pyramid consists of plants that
contain 450,000 Calories of food energy. If all the plants were eaten by
mice and insects, how much food would be available to those first level
consumers?
 If all the mice and insects were eaten by snakes, how much food
energy would be available to snakes?
 If all the snakes were eaten by a hawk, how much food energy would
be available to the hawk?
 How much food energy would the hawk use for its body processes and
lose of heat?
 How much food would be stored in the hawk’s body?

21. 3.2 Ecology
Section Assessment
1. Solar energy is harnessed by autotrophs that
conduct photosynthesis. Chemical energy – the
energy within the chemical bonds of inorganic
molecules – is harnessed by autotrophs that conduct
chemosynthesis.
2. Students should describe a one-way flow of energy
from autotrophs (producers) to consumers – first
herbivores, then carnivores and/or omnivores.
3. In general, about 10 percent.
4. The autotroph is the producer, and it is eaten by the
herbivore. The herbivore is then eaten by the
omnivore.
5. Students’ pyramids should show 100% of energy
available at the first (producer) level, 10% at the
second level, 1% at the third level, 0.1% at the fourth
level, and 0.01% at the fifth level.

22. 3.3 Cycles of Matter
Recycling in the Biosphere
 Energy is crucial to an
ecosystem.
 Organisms need more
than energy, they need
water, minerals, and
other life sustaining
compounds.
 In most organisms, 95%
of the body is made up
of just four elements:
oxygen, carbon,
hydrogen, and nitrogen.

23. 3.3 Cycles of Matter
Recycling in the Biosphere
 Matter is recycled within
and between ecosystems.
 Elements, chemical
compounds, and other
forms of matter are passed
from one organism to
another and from one part
of the biosphere to another
through biogeochemical
cycles.
 Matter can cycle through
the biosphere because
biological systems do not
use up matter, they
transform it.

24. 3.3 Cycles of Matter
Water Cycle
 All living things require
water to survive.
 Evaporation – the
process by which water
changes form liquid form
to an atmospheric gas.
 Transpiration – the
process by which water
enters the atmosphere
by evaporating from the
leaves of plants.
Condensation
Precipitation
Runoff
Seepage
Root
Uptake
TranspirationEvaporation
What are some forms of precipitation?

25. 3.3 Cycles of Matter
Nutrient Cycles
“Every living organism needs
nutrients to build tissues and carry
out essential life functions. Like
water, nutrients are passed between
organisms and the environment
through biogeochemical cycles.”
 The food you eat
provides energy and
chemicals that keep
YOU alive.
 Nutrients – all the
chemical substances
that an organism
needs to sustain life.
(“building blocks”)

26. 3.3 Cycles of Matter
Carbon Cycle
 Biological processes, such as
photosynthesis, respiration,
and decomposition, take up
and release carbon and
oxygen.
 Geochemical processes, such
as erosion and volcanic
activity, release carbon dioxide
to the atmosphere and oceans.
 Mixed biogeochemical
processes, such as the burial
and decomposition of dead
organisms and their conversion
under pressure into coal and
petroleum (fossil fuels), store
carbon underground.
 Human activities, such as
mining cutting, and burning
forest and fossil fuels, release
carbon dioxide into the
atmosphere.
CO2 in
Atmosphere
CO2 in Ocean

27. 3.3 Cycles of Matter
The Nitrogen Cycle
 All organism need nitrogen to
make amino acids.
 N2 makes up 78% of Earth’s
atmosphere.
 Ammonia (NH3), nitrate ions
(NO3-), and nitrite ions (NO2-)
found in waste products and
dead or decaying matter.
 Only certain bacteria can use
nitrogen directly
 Nitrogen Fixation – convert
nitrogen gas into ammonia, then
to nitrite or nitrates
 Denitrification – covert nitrates
into nitrogen gas, releasing back
into the atmosphere.
N2 in Atmosphere
NO3
-
and NO2
-
NH3

28. 3.3 Cycles of Matter
The Phosphorus Cycle
 Phosphorus is an
important component of
DNA and RNA.
 Does not enter the
atmosphere, remains on
land in rock and soil and
ocean sediments.
 Plants absorb phosphate
from the soil or from
water and binds the
phosphate into organic
compounds.
 Moves through the food
web from producers to
consumers

29. 3.3 Cycles of Matter
Nutrient Limitation
 Primary productivity - the
rate at which organic matter
is created by producers
(affected by available
nutrients).
 When an ecosystem is
limited by a single nutrient
that is scarce or cycles
slowly, this is called the
limiting nutrient.
 Fertilizers contain: nitrogen,
phosphorus, and potassium.
 Algal bloom – an immediate
increase in the amount of
algae and other producers.

30. 3.3 Cycles of Matter
Section Assessment
1. Unlike the one-way flow of energy, matter is recycled
within and between ecosystems.
2. To build tissues and carry out life functions.
3. A good response should describe the different forms
of nitrogen as well as explain bacterial nitrogen
fixation and denitrification.
4. If a nutrient is in short supply, it will limit an
organism’s growth.
5. If vast areas of forest were cleared, less carbon
dioxide would be removed from the atmosphere by
plants.
6. When an aquatic ecosystem receives a large input of
a limiting nutrient, the result is often an algal bloom.
Algal blooms can sometimes disrupt the equilibrium
of an ecosystem by producing more algae than
consumers can eat.