Download 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, carnivorous, long canine teeth, warm
blooded, feed young milk.
▸** Quantitative - how many eyes, how long the teeth are
(International System of measuring; commonly known as SI)
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.
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?
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
Niche - the role and position a species has in
its environment.
Each species is unique in how it satisfies all of
its needs.
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 benefitted.
○ 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
decomposers.
– Chains consist of 3 steps - but most have 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.
▸
▸
▸
▸
▸
1.
2.
3.
4.
5.
Shows how energy flows through a ecosystem.
Each Pyramid summarizes interactions of matter and energy at each Trophic level.
The total energy transfer from one Trophic level to the next is only about 10%.
The energy lost enters the environment as heat.
A pyramid of numbers is based on population size.
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.
Food Web
Pyramid of Numbers
Pyramid of Energy