Chapter 2 Principles of Ecology

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Chapter 2 Principles of Ecology

• You will learn

1. What an ecologist does. 2. Some important
aspects of an
organisms environment. 3.Trace the flow of
energy and nutrients in the living and nonliving
worlds
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Why its important To understand life.

• Know how organisms meet their needs.
• Reduce the impact of the human population.
• Understand how living things depend on
  their environment.

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2.1 ORGANISMS AND THEIR ENVIRONMENT
A. What is Ecology? The Scientific study
of interactions among organisms and their
environment

• 1. Ecological study reveals relationships among
  living and nonliving parts of the world
  Techniques include the fields of
  mathematics, chemistry, physics, geology
  and many more.
• 2. Scientific research includes both
  descriptive and quantitative methods.
• Descriptive - fur, Carnivora long, canines
  teeth, fur, warm blooded, feed young milk.
• Quantitative - how many (International
  System of measuring commonly known as SI

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3. What are some of the things we can
learn from scientific research?

• Think about what it would be like without water
  treatment plants, vaccinations, microwaves etc..
• Technology has caused problems as well. For
  example over irrigation, toxic waste etc..

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II. Aspects of Ecological Study

• A. Living things can be found in the air, on
  land and both fresh and salt water.
• B. The Biosphere is the portion of Earth
  that supports life.
• C. Nonliving Environment.
• Abiotic factors - nonliving part of an
  organisms
• environment.
• (Name some)
• 1. What are some of the effects of
  Abiotic factors.?

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• D. The living Environment
• 1. Biotic factors - All the living organisms
  that inhabit an environment. (Name some)
• 2. How do living plants affect you?
• How do dogs affect you?

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III. Levels of Organization in Ecology
All organisms depend on others for food, shelter,
protection and reproduction.

• Biosphere
• Ecosystem
• Communities
• Populations
• Organisms

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A. Interactions within populations

• 1. Populations - a group of organisms of
  one species that interbreed and live in
  the same place at the same time.
• 2. Members compete - only if
  resources are in short supply.
• Members share.

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• B. Individuals interact within
  Communities
• No species lives independently of other species.
• 1. Community - a collection of
  interacting populations
• 2. A change in one population in a
  community will cause changes in other
  populations.

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• C. Interactions among living
  things and abiotic factors from ecosystems
• Ecosystems - The interaction among the
  populations in a community and the communitys
  abiotic factors.
• Three kinds of Ecosystems
• A. Terrestrial land
• B. Aquatic - lakes and rivers
• C. Marine -oceans and seas

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IV. Organisms in Ecosystems
A habitat is the place where an organism lives.
Habitats can both change and even disappear

• A. Niche - the role and position a species
  has in its environment. Each species is
  unique in satisfying all its needs.
• B. Living relationships
• Some species enhance their chances of survival
  by forming relationships with other species

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Types of Living Relationships

• 1. Symbiosis - living together
• 2. Predator/prey - one species gets
  food the other is eaten.
• 3. Commensalism - one species
  benefits. The other is neither
  harmed nor benefitted.
• 4. Mutualism - two species living
  together both are beneficed.
• 5. Parasitism - One species is
  benefitted the other is harmed but is
  not usually killed .

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2.2 Nutrition and Energy Flow
I. How Organisms obtain energy Energy
drives all events walking, flowering and
reproducing. The ultimate source of energy on
Earth is the Sun.
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• A. The producers Autotrophs.
• Organisms that use energy from the sun or energy
  stored in chemical compounds to make their own
  nutrients.
• Plants, some unicellular organisms are the most
  common.

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• B. the Consumers Heterotrophs
• Organisms that obtain nutrients by eating other
  organisms.
• 1. Herbivores - eat plants
• 2. Carnivores - eat animals
• A. Scavengers - feed on carrion and refuse
• Why are scavengers important?
• 3. Omnivores - eat both plant and animal
  material.
• 4. Decomposers - fungi breakdown dead and
  decaying material

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II. Matter and Energy flow in Ecosystems

• A. Food Chains Pathways for matter and energy
• Nutrients and energy proceed from Autotrophs
  to Heterotrophs and then to decomposes.
• Chains consist of 3 steps but most --no more
  than five. Why?
• B. Trophic Levels represent links in the
  chain.

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• Each step in a chain represents a Trophic
  level.
• C. Food Webs - all the possible feeding
  relationships at each Trophic level
  in a community.
• D. Energy and Trophic levels Ecological
  pyramids.

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• D. Energy and Trophic levels
• Ecological Pyramids
• 1. Shows how energy flows through an
  ecosystem
• 2. Each Pyramid summarizes interactions of
  matter and energy at each Trophic Level.

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• 3. The total energy transfer from one
  Trophic Level to the next is only
  about 10
• 4. The energy lost enters the environment as
  heat.
• 5. A pyramid of numbers is based on
  population size.

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Pyramid of Numbers
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Pyramid of Energy
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III. Cycles in Nature
The elements that make up the bodies of organisms
alive today are the same atoms that have been on
Earth since life began.

• A. Water cycle

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B. Carbon Cycle
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C. Nitrogen Cycle
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D. Phosphorus Cycle