Transcript Chapter 2 Principles of Ecology

Chapter 2 Principles of Ecology
You will learn:
1. What an ecologist does.
2. Some important aspects of an
organism’s environment.
3.Trace the flow of energy and nutrients in
the living and nonliving worlds
Why it’s 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.
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
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..
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.?
• 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?
III. Levels of Organization in Ecology
All organisms depend on others for food,
shelter, protection and reproduction.
Biosphere
Ecosystem
Communities
Populations
Organisms
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.
• 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.
• C. Interactions among living
things
and abiotic factors from
ecosystems
• Ecosystems - The interaction among the
populations in a community and the
community’s abiotic factors.
• Three kinds of Ecosystems
• A. Terrestrial — land
• B. Aquatic - lakes and rivers
• C. Marine -oceans and seas
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
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 .
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.
• 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.
• 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
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.
• 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.
• 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.
•
• 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.
Pyramid of Numbers
Pyramid of Energy
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
B. Carbon Cycle
C. Nitrogen Cycle
D. Phosphorus Cycle