Download Ecosystems Notes

Name ________________________________________________________________________________________ Date____________________ Period________________
ECOLOGY
(Chapters 3 & 4.2 )
 What is Ecology

Ecology is the scientific study of ________________________________________________ among organisms and between
organisms and their environment.

Planet can be divided into two large factors:
1. Abiotic = _____________________________________________________________________________________________
Ex. climate, wind, nutrients, humidity
2. Biotic = _______________________________________________________________________________________________
Ex. plants, animals, bacteria

LEVELS:
LEVEL

DEFINITION
EXAMPLE
The abiotic and biotic factors of an ecosystem are interconnected, a ________________________________ is the
role an organisms plays in its ecosystem
 Energy Flow

Ultimately all organisms depend on the __________________________________ for energy

Organisms may use energy from the sun in two different ways:
1. directly (autotrophs or producers – _______________________________________________________________________)
2. indirectly (heterotrophs or consumers – __________________________________________________________________)

_________________________________________ – 2 types:
1. Photoautotrophs: obtain their energy through ____________________________________ (using light energy)
2. Chemoautotrophs: obtain their energy through _______________________________ (using chemical energy)

________________________________________ – 4 types:
1. Herbivores eat only __________________
2. Carnivores eat only ____________________________ (meat)
3. Omnivores eat ____________________________________________________________________________
4. Detritivores eat ______________________________________ (plant and animal remains – _______________________)

Food Chains/Webs

Energy flows through an ecosystem in one direction: from the ___________________________________________
to _____________________________________ then to various ________________________________________

Organisms transfer energy in a chain/web by _______________________ and being __________________________

Each step in a food chain/web is called a trophic level

o
1st Trophic Level = ___________________________________
o
2nd Trophic Level = ____________________________ (First-level) Consumer
o
3rd Trophic Level = ___________________________ (Second-level) Consumer
o
4th Trophic Level = _____________________________ (Third-level) Consumer
o
5th Trophic Level = ______________________________ (Forth-level) Consumer
Label the trophic levels and add arrows to create a food chain
 Cycles of Matter

Unlike the one-way flow of energy, matter is ___________________________ within and between ecosystems

Elements, chemical compounds, and other forms of matter are passed form one organisms to another
and from one part of the biosphere to another through biogeochemical cycles (biological, geological,
chemical)

4 Types:
1. _______________________ Cycle
2. _______________________ Cycle
3. _______________________ Cycle
4. _______________________ Cycle
 Ecological Pyramids

At each trophic level __________________________ energy is given off

Energy only goes in one direction: ___________________________________________________________________________

There are three types of ecological pyramids:
1. Energy Pyramids show _________________________________________________________________________________
____________________________________________________________________________________________________________
2. Numbers Pyramids show ______________________________________________________________________________
____________________________________________________________________________________________________________
3. Biomass Pyramids show _______________________________________________________________________________
____________________________________________________________________________________________________________

As you move up trophic levels, approximately _________________________ of energy is passed on

Because only 10% of the energy is moving up to the next trophic level, it makes sense that it would
be able to support less organisms
Ecological Pyramid Questions
1. A rabbit has 400 kJ of energy at the primary consumer level – if it is eaten by a snake at the
secondary consumer level, how much energy will the snake receive?
2. Describe how the numbers pyramid would look different if it was an ecosystem with large trees
instead of an ecosystem with lots of grass.
3. How much energy would a quaternary consumer receive if the producer started with 50,000 kJ.
4. List the approximate biomass amounts for the 2nd, 3rd, and 4th trophic level if the 1st level had
2000g.