Chapter 2: Principles in Ecology

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Chapter 2 Principles in Ecology
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2-1 What is ecology WARM UP

• What living things are found in and around your
  school?
• 2. What nonliving things are found in your
  school?
• 3. Into what large groups are the students in
  your school divided?
• 4. Into what smaller groups are these large
  groups divided?
• 5. Are these groups ever divided into even
  smaller groups? If so, what are these groups?

• An ecosystem is a collection of all the organisms
  that live in a particular place, together with
  their nonliving, or physical, environment. Within
  an ecosystem, there are several levels of
  organization. Your school and its grounds are
  similar to an ecosystem.

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EQ 1What is Ecology?

• Interactions and Interdependence
• Levels of Organization
• C. Ecological Methods
• 1. Observing
• 2. Experimenting
• 3. Modeling

• Ecology The scientific study of interactions
  among organisms and between organisms and their
  environment, or surroundings.

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EQ 2 How are the different levels of
organization of life related?

• Species (individual) can breed and produce
  fertile offspring
• Population groups of individuals that belong to
  the same species and live in the same area.
• Community different populations that live
  together in a defined area.
• Ecosystem a collection of all the organisms
  that live in a particular place, together with
  their nonliving, or physical, environment.
• Biome A group of ecosystems that have the same
  climate and dominant communities.
• Biosphere Contains the combined portions of the
  planet in which all of life exists, including
  land, water, and air or atmosphere.

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EQ3 What types of ecological Methods do
ecologists use to study the living world?

• Observing
• Experimenting
• Modeling

• All of these methods rely on the application of
  scientific methods to guide ecological inquiry.

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Check for Understanding

1. List the six different levels of organization
   that ecologists study, in order from smallest to
   largest.
2. Describe the three basic methods of ecological
   research.
3. Identify two ways in which you interact with each
   of the three parts of the biosphere every day
   land, water, and air.

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2-2 Energy Flow WARM UP

• Energy flows in one direction through an
  ecosystem, from the sun or inorganic compounds to
  producers (organisms that can make their own
  food) through various levels to consumers
  (organisms that rely on other organisms for
  food). Your body gets the energy and materials it
  needs for growth and repair from the foods you
  eat.

• Make a list of five foods that you like to eat.
  Indicate whether the food comes from a plant
  (producer) or an animal (consumer).
• Like many birds, chickens eat grains, which are
  seeds. Where do seeds come from?
• Meat comes from beef cattle. What do cattle eat?
• Construct a diagram showing how one of your
  favorite foods obtains its energy. Include as
  many levels as you can.

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EQ 4 How does energy flow through the biosphere?

• Sunlight is the main energy source for life on
  Earth.
• Some types of organisms rely on the energy stored
  in inorganic chemical compounds

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Energy Flow Through the Biosphere

• Autotrophs Use energy from the environment to
  make their own food. (Producers)
• Ex plants, some algae and some bacteria.
• Photosynthesis Adds oxygen to the environment
  and remove carbon dioxide. Glucose is also
  produced.
• Chemosynthesis when organisms use chemical
  energy to produce carbohydrates.

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Consumers

• Organisms that rely on other organisms for their
  energy and food supply
• Heterotrophs (consumers)

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Consumers

• Herbivores eat only plants
• Carnivores eat animals
• Omnivores eat both plants and animals
• Detritivores eat plant and animal remains and
  other dead matter (detritus)
• Decomposers breaks down organic matter

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EQ 5 What happens to the energy in an ecosystem
when one organisms eats another?

• Energy flows through an ecosystem in one
  direction
• Sun or inorganic compounds ? producers ?
  consumers
• Food chains show one-way flow of energy
• Food webs links food chains
• Trophic levels steps in food chains or food
  webs.

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Energy Pyramids

• step trophic level.
• Show energy movement through the environment.
• Only 10 available to next level

Energy decreases as you go up the pyramid
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Draw this pyramid
(Omnivore)
Heterotroph
(Carnivore)
(Herbivore)
(Autotroph)
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Pyramid of Numbers Shows the relative number of
individual organisms at each trophic level.
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.
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Figure 54.13 A pyramid of numbers
Why does the number of organisms decrease as you
go up the pyramid?
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Figure 54.14 Food energy available to the human
population at different trophic levels
Why must humans consume more food?
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Check for Understanding

• What are the two main forms of energy that power
  living systems?
• Briefly describe the flow of energy among
  organisms in an ecosystem
• What proportion of energy is transferred from one
  trophic level to the next in an ecosystem?

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FOOD WEB PRESENTATION 25 Pts

• 5 pts. The food web must contain at least five
  food chains consisting of a producer, a primary
  consumer, and a secondary consumer.
• 5 pts. Each consumer must be labeled as an
  herbivore, carnivore, omnivore, or decomposer.

• 5 pts. At least one predator-prep relationship
  must be shown.
• 5 pts. Five abiotic factors (non-living) also
  must be included and labeled.
• 5 pts. You will need to explain your poster to
  the class in oral presentations.

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2-3 Cycles of Matter

• EQ How does matter cycle among the living and
  nonliving parts of an ecosystem?
• EQ What would happen to a living system that was
  nutrient deficient?
• How does the availability of nutrients affect the
  productivity of ecosystems?

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Its Raining, Its Pouring

• When rain falls on the ground, it either soaks
  into the soil or runs across the surface of the
  soil. When rainwater runs across the land, what
  body of water might collect the rain?
• From here, where might the water flow?
• After the rain, the sun comes out and the land
  dries. Where does the water that had been on the
  land go?
• Construct a diagram that would illustrate all the
  places a molecule of water might go. Begin with a
  raindrop and end with a cloud.

• How many times have you had to change your plans
  because of rain? It probably didnt help if
  someone tried to cheer you up by saying, But we
  really need the rain.
• However, rain is important. If it didnt rain,
  how would living things on land get water?

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Recycling in the Biosphere

• Unlike the one-way flow of energy, matter is
  recycled within and between ecosystems.
• Biological systems do not use up matter, but
  transform it.

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Nutrient Cycles

• Organic Nutrients- CHNOP
• 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 biochemical
  cycles.
• Video clip-http//www.unitedstreaming.com

• Water Cycle
• Carbon Cycle
• Nitrogen Cycle
• Phosphorus Cycle

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The Water Cycle
All living things require water to survive.
Where does it all come from?
Condensation
Precipitation
Runoff
Seepage
Root Uptake
It moves between the ocean, atmosphere, and land.
This figure shows how water molecules can change
forms and be used through evaporation (change
from liquid to gas) and transpiration (by
evaporating from the leaves of plants).
Go to Section
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The Carbon Cycle

• Biological processes, such as photosynthesis,
  respiration, and decomposition of plants and
  animal
• Geochemical processes, such as the release of
  carbon dioxide (CO2) gas to the atmosphere by
  volcanoes

• Mixed biogeochemical processes, such as the
  burial of carbon-rich remains of organisms and
  their conversion into coal and petroleum (fossil
  fuels) by the pressure of the overlying earth
• Human activity, including mining, the burning of
  fossil fuels, and the cutting and burning of
  forests.

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The Carbon Cycle
CO2 in Atmosphere
CO2 in Ocean
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Nitrogen Cycle
Is driven primarily by the activities of
unicellular organisms in the soil and oceans.
1. Nitrogen is in the atmosphere all the
time. 2. Bacteria change the nitrogen gas into
nitrates (ammonium), which is a kind of natural
fertilizer taken in by the roots of plants and
trees and used to build plant protein. This
process of change is called nitrogen fixation. 3.
Animals then eat the plants with protein in
them 4. Animal and plant waste then releases
protein into the soil through decomposition. 5.
Finally, more kinds of bacteria break down plant
protein to a form that releases nitrogen back
into the atmosphere. This process is called
denitrification
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The Nitrogen Cycle
N2 in Atmosphere
NO3- and NO2-
NH3
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Phosphorus Cycle

• Phosphorus is essential to living organisms
  because it forms part of important
  life-sustaining molecules such as DNA and RNA.
• Phosphorus does not enter the atmosphere like
  oxygen, carbon and nitrogen
• phosphorus remains mostly on land in rock and
  soil minerals, and in ocean sediments

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Phosphorus Cycle

• When plants absorb phosphate from the soil or
  from water, the plants bind the phosphate into
  organic compounds.
• Organic phosphate moves through the food web,
  from producers to consumers, and to the rest of
  the ecosystem.

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Nutrient Limitation

• Primary productivity rate at which organic
  matter is created by producers
• Controlled by the amount of available nutrients
• Limiting nutrient when an ecosystem is limited
  by a single nutrient that is scarce or cycles
  very slowly.

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Checkpoint!!!!
1. How does the way tat matter flows through an
ecosystem differ from the way that energy
flows? 2. Why do living organisms need
nutrients? 3. Describe the path of nitrogen
through its biogeochemical cycle. 4. Explain how
a nutrient can be a limiting factor in an
ecosystem.