Chapter 13 Ecology
Name:___________________________________________________
13.1 Ecologist Study Relationships
 _______________________ – the study of living things and their relationship with each other and with the
environment
*Ecology can be studied at different levels, from a local to a global scale
1. ___________________________– An individual living thing, such as an alligator
2. ___________________________ – group of same species that lives in one area, such as a group of alligators
living in a swamp
3. ___________________________ – all of the living things in a given area
4. ___________________________ – all of the living and nonliving things in a given area
5. ___________________________ – a major regional or global community of organisms, usually
characterized by the climate conditions and plan communities that thrive there.

Examples: tropical, grassland, desert, temperate, taiga, tundra
6. _____________________ – portion of the Earth where all life exists
Ecological research methods include…
 ____________________________________ – the act of carefully watching something over time.
◦
________________________: naked eye, binoculars
◦
________________________: feces, recent kill
 ________________________________ – scientists can perform experiments in the lab or the field.
 ______________________________– Using computer or mathematical models to describe and model nature
13.2 Biotic and Abiotic Factors
Key Concept: Every ecosystem includes both living and nonliving factors

___________________________________ are living things, or things that were once living

Examples: plants, animals, fungi, and ___________________

Each organism plays a particular ________________ in the ecosystem.

___________________________________ are nonliving

Examples: moisture, ________________________________ wind, sunlight, and ________________________.

The balance of these factors determines which living things can live in a particular
environment.
Biodiversity is important to an ecosystem
 ___________________________ is the assortment, or ___________________, of living things in an ecosystem.
 ______________________________________: A species that has an unusually _______________________ effect on its
ecosystem. The loss of a keystone species from an ecosystem can have a ripple effect.
◦ Example: Beavers create dams, which are an ecosystem used by a wide variety of species.
13.3 Energy in Ecosystems
 Life in an ecosystem requires a source of _______________________
 _____________________________________________for other organisms in an ecosystem.
◦
___________________________________: An organism that gets their energy from non-living
resources. Example: Plants

Also called ____________________________

Get energy from photosynthesis or ___________________________________

___________________________________ process by which an organism forms
carbohydrates using _______________________ as an energy source.
 _________________________ are organisms that get their energy by eating
_______________________________________________________________
◦
Also called ______________________________________
◦
All consumers somehow depend on producers for food.
◦
Examples: ______________________________________________
13.4: Food chains and food webs
 Food chains and food webs model the flow
of energy in an ecosystem.
 _____________________________________: a model that shows
a sequence of feeding relationships.
◦
Shows the transfer of ___________________
from one organism to another
◦
Each level of nourishment in a
food chain is called a ________________________________
Not all consumers are alike.
 _______________________: Eat only plants. Example: rabbits
 ______________________: Eat only ____________________ Example: lion
 __________________________: Eat both plants and animals. Example: kangaroo rat.
 ___________________________: Eat detritus, or____________________________________________.
◦
Examples: millipede
 _____________________________: A type of detritivore that breaks down organic matter into simpler
compounds, returning _________________________________________back into their environment.
◦
Example: ___________________________
Other types of consumers
 _______________________________: a consumer that primarily eats one specific organisms or feeds on a
very small number of organisms.
◦
_________________________________ to changes in the availability of prey.
 _______________________________: consumers that have a varying diet (most species).
Energy flows from the lowest trophic level to the highest trophic level
 Producer to primary consumer to secondary consumer to tertiary consumer
 _______________________________________ are herbivores (or omnivores)
 Secondary consumers are ___________________________(or omnivores)
 Tertiary consumers are ________________________________(or omnivores)
Food Webs
 A ______________________________ is a model that shows the complex network of feeding relationships
and the flow of _______________________within an ecosystem.
Energy Pyramids
 A ________________________ of numbers shows the numbers of individual organisms at each trophic
level in an ecosystem.
•
Between each tier of the energy pyramid, up to ___________________of the energy is
_______________________________________________________________.
•
Only ______________________of the energy at each tier is
____________________________________________________________________________.
 A __________________________________ of producers are required to support even a few top level
consumers.
3.5 KEY CONCEPT
Matter cycles in and out of an ecosystem.
• It changes form, but does not disappear.
• The total amount of matter remains the same.
5,000,000
Water cycles through the environment.
 The ____________________________, or water, cycle is the circular pathway of water on Earth.
Organisms all have bodies made mostly of water.
Elements essential for life also cycle through ecosystems
-examples: oxygen, carbon
 A __________________________________________cycle is the movement of a
particular chemical through the biological and geological parts of an
ecosystem.
The Oxygen Cycle
 _____________________________ can cycle indirectly through an ecosystem
by the cycling of other nutrients.
The Carbon Cycle
 __________________________is the building block of living organisms.
◦ Carbon comes in all three forms (solid, liquid, gas)
◦ CO2 gas
◦ HCO3 (bicarbonate- dissolved in water)
◦ Fossil Fuels (underground) oil, natural gas, coal
◦ Carbonate rocks (limestone)
◦ Dead Organic Matter
The Nitrogen Cycle

photosynt
hesis
Carbon dioxide
dissolved in
water
Respiration
The _______________________cycle mostly takes place underground.
o Some bacteria convert gaseous nitrogen into ammonia through a process called
____________________________________________.
o Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in
the soil.
o ________________________________ can split nitrogen molecules in the atmosphere which can
add nitrogen to the soil.
Step One: Ammonia (NH3) released into the soil is transformed into ammonium – some is
taken up by plants
Step Two: Nitrifying bacteria change the ammonium into nitrate.
Step Three: Nitrate is taken up by plants and converted into organic compounds like
amino acids and proteins.
Step Four: Nitrogen moves through the food
web and returns to the soil during decomposition as ammonium.
Phosphorus Cycle
The ____________________________cycle takes place at and below ground level – it does not include an
atmospheric portion.
1. Phosphate is _______________________by the weathering of rocks.
2. _______________________________________ found near plant roots are able to take up phosphate
3. Phosphorus moves through the _______________________ and returns to the soil during
________________________________________.
– Phosphorus leaches into groundwater from the soil and is locked in sediments.
– Both mining and agriculture add phosphorus in to the environment.