Name: ________________________________________________________
Per: ________
Test Date:____________________
Ecology Notes
Levels of Organization/Food Chains and Food Webs
Ecology definition:
-Eco: from Greek oikos, meaning “house”
I. Levels of Organization from the most general to most specific
A. __________________: An individual member of a species. A member of a species must be able to mate
and produce fertile offspring.
B. _____________: A group of the same species living in the same area.
C. _________________________: A group of different species that live together in one area.
D. _________________________: All of the organisms (biotic factors) as well as the climate, soil, water, rocks
and other nonliving things (abiotic factors) in a given area.
E. ______________: A major regional or global community of organisms, usually characterized by the
climate conditions and plant communities of the region
F. ________________________: All of Earth including its atmosphere
II. Energy in an Ecosystem: Food Chains, Food Webs, and Food Pyramids
A. Definitions:
1. ____________________: the place in which an organism lives ex: a deer lives in a ______________
2. ___________________: an organism’s role in the food chain ex: a deer is a ______________ ______________
(herbivore) because it feeds upon plants
B. Types of Niches
1. ________________________________ (Producers)
a. ______________________: can photosynthesize and produce food using energy from the sun
Example: plants and some protists
b. ______________________: can produce food from inorganic chemicals in the environment
Example: some bacteria
2. _______________________(Consumers: eat other organisms)
a. ______________________: eat plants
ex: _________________
b. ______________________: eat meat
ex: __________________
c. ______________________: eat plants and animals
ex: _________________
d. ______________________: eat animals that are already dead (carrion)
ex: _________________
e. ______________________: breakdown dead organisms and return their nutrients to the soil.
Examples: ___________________and ______________________
C. Types of Heterotrophs in a Food Chain/Food Web
1. _________________ ____________________ (1st level consumers): feed upon plants (herbivores)
2. _________________ ____________________ (2nd level consumers): feed upon primary consumers
3. _________________ ____________________ (3rd level consumers): feed upon secondary consumers
4. _________________ ___________________ (4th level consumers): feed upon tertiary consumers
D. Types of Symbiosis
When two organisms live in close contact, they form a symbiotic relationship.
 _______________________: both organisms benefit.

_______________________: one organism benefits and the other is neither harmed nor benefitted

_______________________: one organism benefits while the other is harmed
1) Mutualism Examples
 Bacteria on the roots of some plants provide the plant with nitrogen to make proteins,
and the plant provides the bacteria with a place to live.
 Crocodile opens wide for the plover because the plover likes to pick its teeth clean of
rotting meat. Free dental care, free meal.
2) Commensalism Examples
 ________________________ Barnacles are _______________, filter-feeders. They will starve if they
are in polluted water. If they attach to whales, the whales will bring them to unpolluted
water to feed. The whales are not harmed nor helped by the relationship.
 The bird benefits from the shelter of the tree and the food supply that the tree attracts.
The tree is not harmed or helped by the bird.
3) Parasitism Examples
 ______________________ in the heart of a dog.
 Adult lice on human.


_______________________________ – two species share a requirement for a limited resource; reduces
fitness of one or both species
____________________________ – one species feeds on another; enhances fitness of predator but
reduces fitness of prey
E. Movement of Energy through a Food Chain/Food Web
a._____________________________: Feeding position in a food chain
1) _______________ indicate the direction of energy flow through a food chain / food web
2) Each ecosystem has its own unique trophic structure.
3) ______________________ are always at ____________________ because they produce the food to start
the exchange of energy through an ecosystem
Arrows indicate direction of energy flow
Trophic Level 4
Tertiary
Trophic Level
Secondary
Trophic Level
Trophic Level
Primary
Producer
Decomposer
b._____________________________: _______________, linear diagram of ENERGY FLOW through an ecosystem
c. ______________ ______________: A more ___________________ diagram that shows all of the various
predator/prey relationships in an ecosystem
F. ______________________ __________________: shows the reduction in energy available at each higher
trophic level
1. ____________________must comprise ______________ of the mass of the biotic part of the ecosystem
* This is the only place where (solar) energy enters the ecosystem.
2. ___________________ is always ___________ in the form of _____________ so energy transfers are only
_______________% efficient at each trophic level. (90% of the energy is “lost” as heat energy to the
atmosphere at each level)
G. Pyramid of Numbers: Each higher trophic level decreases by 90% (only 10% remains)
H. Pyramid of Biomass:
1. _________________ form the broad base of the food pyramid because they have the greatest biomass
(________________) as primary producers that convert sunlight into food through photosynthesis.
2. The second level represents the primary consumers, the herbivores that consume plants. This
second level has _____ ___________ than the base because almost 90% of the energy consumed by
herbivores is lost as __________________ or waste products that are broken down by decomposers.
World Biomes
III. Biomes
Definition:
A. Named for the most conspicuous _____________________________
B. Climate factors:
i. _________________________________ (precipitation)
ii. _________________________________
iii. _________________________________
iv. _________________________________
C. Boundaries are distinct
D. 6 Major World Biomes
1) ______________________________________
2) ______________________________________
a. Subtropical / Tropical aka Savannah
b. Deciduous
3) _______________________________________
4) _______________________________________
a. Temperate Deciduous Forest
b. Temperate Rainforest
5) ______________________________________aka Coniferous Forest or Boreal Forest
6) ______________________________________
Homeostasis of Biomes
 Delicate balance of:
 Temperature and water balance
 Light and biological cycles
 Ecology and conservation
 Pollution




Environmental Concerns
 Pollution clear cutting
 Illegal logging
 Poaching
 Forest fires – unnatural fires
Predation
Competition
Symbiosis
Human impact



Mining
Drilling for oil and natural
gas
Global warming
1. _________________________________________
a. Equatorial lowlands
b. Constant temperature and abundant _______________ all year long.
c. Many arboreal _______________________
d. Very few ______________________________ animals
2a. Subtropical/Tropical (____________________________)
a. Warm temperatures throughout the year
b. Well defined dry season and rainy season
c. Large ______________________________
d. Tall _________________________________
e. Scattered trees and shrubs
2b. ________________________________________
a. Hot, humid summer and cold winter
b. Precipitation as winter snow and heavy rain in the spring and summer
c. Tall and short _________________________; trees and shrubs only located near streams
d. Wide variety of animal life
1. large ___________________________
2. smaller animals build burrows
Grassland Adaptations
• Native plants are perennials while crop grains are annuals
• Half the plant growth is below the ground
• Dominated by grazing animals (deer, antelope, buffalo- once common but now rarely native
to the area)
• Herds (safety in numbers)
• Burrowing small animals (colonies such as prairie dogs.
3. _____________________________
a. Identified by lack of ________________________________
b. Deserts can be cold or hot
Example- Antarctica is a _________________ ______________________
c. Nocturnal animal life in hot deserts
d. Plants are well adapted to __________ ____________ ______________
4a. __________________________________________________
a. Deciduous forests (trees ____________ _____________ in winter) of mid-latitude region
b. _____________ winters and ____________ summers
c. Abundant rain and snowfall
d. ______________ ____________________ of animal life
4b. ________________________________________
a. Cold winters and hot summers
b. Abundant rain and snowfall
c. (redwoods, pines, spruce, and firs) retain their needles
 ______________conserve water in dry summer and shed snow in cold winter
d. _____________ ___________________ of animal life
5.______________________ aka Coniferous Forest aka Boreal Forest
a. Coniferous (__________________________) Forest (trees retain their needles year-round)
b. Found at high elevations and/or far _____________ ________________
c. Snow accounts for most of the ________________________________
d. ____________________ are adapted to long, cold winters
6. ____________________________
a. Areas with continuously frozen ground (___________________________)
b. Near _______________ regions
c. Small plants limited by __________ ______and prolonged dark season
d. Animals adapted to extreme cold; birds often _____________________
IV. Cycles: Water, Carbon, Nitrogen, Oxygen, and Phosphorous
The elements we have on Earth are the same elements that have been here for 4.6 billion years!
I. Water Cycle: See diagram on page 75 in the textbook
A. Processes involved:
1. _________________________________: water evaporates from lakes, streams, rivers, the ocean, etc.
2. ___________________________: water evaporates from plant leaves
3. ___________________________: latent heating of atmosphere
4. ___________________________: Rain, sleet, snow, and hail
B. Steps involved in the Water Cycle
1. Water evaporates from lakes, streams, rivers, the ocean, etc.
(Water changes from________________________________________)
2. Water may evaporate out of plant leaves on hot, dry days, also. This is called transpiration.
(Water changes from ___________________)
3. Gaseous molecules of water collect together to form clouds
4. When the gaseous molecules lose heat energy, condensation and precipitation in the form of
rain, sleet, snow, or hail occurs.
(Water changes from _____________________________________)
5. Water, in the form of precipitation, gets absorbed by plant roots in the soil. It also forms
________________ and is carried into streams, lakes, ponds, etc. where it may eventually make its
way back to the ocean.
6. Water may also trickle down deeply in the soil forming _________.
II. Carbon Cycle: See diagram on page 76 in the textbook.
A. Processes involved:
1. ___________________________________:
6CO2 + 6H2O
C6H12O6 + 6O2
reactants
products
2. ____________________________________:
C6H12O6 + 6O2
6CO2 + 6H2O
____________
_______________
3. ____________________________________: bacteria/fungi breakdown dead organisms and return their
nutrients to the soil
4. ____________________________________: burning fossil fuels
B. Steps involved in the Carbon Cycle:
Step 1: Plants use ___________________ (CO2) from the air and _____________ (H2O) to make the
__________________, glucose (C6H12O6).
Step 2: __________________eat plants and receive sugar (energy); they breathe in oxygen (O2) and
breakdown the sugar to release energy and breathe out ____________________________________(CO2).
Step 3: Plants use carbon dioxide (CO2) and animals and plants die and get _________________________
by ______________________and ___________________________ in the soil to return nutrients to the soil.
III. Nitrogen Cycle: See diagram page 77 in textbook.
A. Processes involved:
1. ___________________________________ by bacteria in the soil
( N2
NO3)
Nitrogen gas
Nitrates
2. ___________________________________
( N2
NH4)
Nitrogen gas
Ammonium
B. Steps Involved in the Nitrogen Cycle
1. ______________________________________________ from the air (N2
NO3)
2. Producers and consumers incorporate nitrogen in their __________________ (Make Proteins using
the nitrogen)
3. Nitrogen can be fixed industrially from the air, i.e. production of
_____________________________(NH3)
4. ____________________ processes return nitrogen to the air
5. Nitrogen from _________________ may contaminate water sources
V. Succession, Population Growth, Pollution, and Biomagnification
A. ________________________________________- natural changes that take place in an ecosystem
1. _______________ ____________________________- the sequence of changes that take place in an ecosystem
where no life had previously existed. Ex: In 1963, a new, volcanic island called Surtsey rose out of
the ocean off the coast of island
 Occurs on an area of newly exposed rock or sand or lava or any area that
________________________________ occupied previously by a living (biotic) community
2. ________________ ___________________________- the sequence of changes that take place in an ecosystem
when communities are disrupted by humans or natural disasters such as fires, hurricanes,
volcanoes, floods, etc.
 Occurs after disturbances that are not intense enough to kill all plants, so that regeneration can
occur by re-sprouting and growth of surviving individuals, and by the _____________________ of preexisting seeds to establish new plants.
B. Population Growth
1. ________________________ _________________________
Populations are very small at the beginning then rise rapidly as
organisms appear. Growth continues exponentially because it is
limited by food supply, space, disasters, etc.
more
not
2._________________________ ____________________
A more realistic growth curve; a population is very small at the
beginning, then grows extremely fast into a population explosion, then
levels out as it reaches the carrying capacity of the ecosystem, i.e. the
food supply and available space declines
C. Logistic Growth Definitions
1. ________________________________________________- the population size that can be supported by the
amount of food, space, water, et
2._________________________- regulate the size of the population; ex: food supply, temperature,
disasters, humans
a. ____________________________________________- a biological event that occurs to alter the size of a
population. Diseases that are caused by living organisms such as bacteria and protists as
well as nonliving viruses will spread more quickly in a heavily populated area and affect
the size of the population more readily than in a sparsely populated area.
b. _______________________________________________- a natural event that alters the size of a
population such as a hurricane, volcano, flood, fire, etc.
D._____________________________- The ability or tendency of an organism or cell to maintain internal
equilibrium by adjusting its physiological processes.
You go outside and it is cold.
cold.
Your body
Reasons why the Earth CANNOT maintain homeostasis
temperature
rises. caused by:
1. _________________ ______________
Heater in
your home.
a. ________________ ___________ = CO2 + water
b. ____________________- SO2 (sulfuric acid) + water
c. ___________________- NO2 (nitric acid) + water
2. _____________________ _______________________O3 (ozone) is a natural sunscreen for the earth. It
absorbs harmful radiation emitted by the sun. CFC’s or chlorofluorocarbons destroy O3.
CFC’s are produced by:
a. air conditioning/refrigeration
b. production of Styrofoam
c. aerosol cans
3. _____________________ ________________
– Gases trapped on the earth’s surface caused by _____________ ___________ _________ which emit
CO2 (factories, cars, boats, lawnmowers, etc.)
4. ____________ _________________ caused by:
a. fertilizing crops and gardens
b. aquatic recreational sports
c. spraying pesticides
d. oil spills
e. sewage
E. Biological Magnification
A. Concentrations of harmful chemicals ________________ as it goes up trophic levels in a food chain.
B. Read page 152 for more information!!
F. Resources
1. _______________________ _________________-resource that can regenerate quickly and that is replaceable.
Ex. _________________________________________________________
Renewable resources are not necessarily unlimited. For example, fresh water may become
limited by drought or overuse.
2. _________________________ ___________________- resource that cannot be replenished by natural processes.
Ex. _______________________________________________________________