ECO NOTES
I.IN THE BEGINNING
NATURAL HISTORIANS- people who want to learn as much about living things as possible.
This branch of biology led to ecology.
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ECOLOGY- is the scientific study of interactions between organisms and their environments.
Ecologists use observations and quantitative data and measurements from experiments.
What are some things they might learn from observation? From experiments and data?
II. ECOSYSTEMS-THE LIVING ENVIRONMENT
BIOSPHERE-a thin zone of earth that supports all life. If the earth were an apple, the biosphere
would only be approx. the size or depth of the skin.
Oikos, or ecos is Greek for habitat.
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In each environment there are both living and nonliving factors that affects life. These are
ABIOTIC AND BIOTIC factors.
Abiotic-Non living parts
Biotic-Living organisms that inhabit the environment
What are examples of each?
Why would the abiotic factors be important? (How did abiotic factors affect the animals in “Oh Deer”
or “Deadly Links”?)
III. HIERARCHY OF LIFE
Each ecosystem is made up of one or more COMMUNITIES
A COMMUNITY is all organisms living in a certain area. They do not have to be the same
Species.
 Can you name a community?
Each community is made up of different POPULATIONS. A POPULATION is all the organisms of
the same species, in a given area.
 What is an example of a population?
 Why would scientist want to study populations and communities?
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Why would members of a population be so competitive? What is it that they compete for?
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How does nature cut down on this competition? (frogs/tadpoles)
The organization of life is put into hierarchy levels. The largest to smallest being:
Biosphere-highest level, entire planet with abiotic and biotic factors
Ecosystem-all abiotic and biotic factors in a given area
Community-Ecologists are concerned for this when a new species is added or removed
Populations-Ecologists study patterns, growth rates, and predicts the future of the
population
Organisms-Ecologists study individual behaviors, breeding, life span, feeding, etc…
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How can a change in a population change the community?
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How can a change in an abiotic factor change the ecosystem, community, or population?
An ECOSYSTEM is made up of the interactions among the populations in a community and its abiotic
factors.
Name some different ecosystems. (terrestrial ones like forests, meadows, desert, or aquatic ones such as
freshwater or marine)
The most important thing to remember is that each species has a particular function in its community, and
each community has its role in the ecosystem.
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What might be a coyote’s role in its community?
A NICHE is the role a species plays in a community. The space it needs to live in, its food, and other
conditions all play a part in its niche. The niche includes how a species treats its environment.
 Think about all that is included in your niche.
A HABITAT is the place where an organism lives. It the area that provides it food, water, shelter, and a
place to reproduce.
 Your habitat is not just your house, why?
IV. CYCLES IN NATURE
WATER CYCLE-can be liquid or solid
NITROGEN CYCLE-atmospheric nitrogen makes up 78% of air but we can’t use nitrogen strait
from the air. Its form has to be modified first into usable compounds.
OXYGEN/CARBON DIOXIDE CYCLE-also known as the carbon cycle
*See illustrations for explanation
HETEROTROPHS-organisms that depend on other organisms as a food source.
AUTOTROPHS-organisms that use stored energy or energy from the sun to make their food.
PRODUCERS-another word for autotroph
CONSUMERS-another word for heterotroph
DECOMPOSERS-organisms that break down and absorb nutrients from dead organisms
SCAVENGERS-these are heterotrophs that do not hunt, but eat animals that have already been killed
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Give an example of each.
FOOD CHAIN-a model to show the flow of energy in an ecosystem. It places the different types of
organisms from above.
Sometimes a simple food chain of one group may overlap to another group and you get a FOOD WEB.
V. RELATIONSHIPS IN AN ECOSYSTEM
COMPETITION-organisms compete for food, shelter, mates, water, etc
 Relate to “OH DEER”
PREDATION-one organisms feeds from another
 Human/deer
Wolf/rabbit
PARASITISM-a symbiotic relationship where only one organism benefits and another is harmed.
 Dogs/ticks
ascaris worms/humans
MUTUALISM-relationship where both species benefit
 Acacia tree/ants
COMMENSALISM-one species benefits and the other is neither harmed nor benefits
 Spanish moss/trees
***SYMBIOSIS- simply means living together and there are many fashions in which this happens.