Transcript Ecology Notes

Ecology Notes
Mrs. Peters
Spring 2011
Living vs. Non-Living
Biotic Factors: all living things in an
environment
Ex: Plants, Animals, Bacteria
Abiotic Factors: all non-living things in an
environment
Ex: Rocks, Sun, Water, Air
Ecosystem
Interaction between abiotic and biotic
factors in an environment create an
ecosystem
Ex: Forest, Desert, Mountains,
Ocean
Ecosystem Energy Flow
Two types of organisms
Autotrophs: produce their own energy
(Producers)
Ex: plants
Heterotrophs: depend on others for
energy (Consumers)
Ex: animals
Ecosystem Energy Flow
Types of Heterotrophs:
Herbivore: consume only plants
Ex: cows, rabbits
Carnivore: consume only animals
Ex: Lions
Omnivore: eat both plants and animals
Ex: humans
Ecosystem Energy Flow
Decomposer: absorb decaying or dead
materials
Ex: mushrooms
Scavenger: eats anything
Ex: sea gulls
Ecosystem Energy Flow
Energy enters an ecosystem as sunlight,
autotrophs convert sunlight to food
molecules using photosynthesis
Ecosystem Energy Flow
Food Chain: one series of feeding
relationships
grass
grasshopper
mouse
hawk
Food web: all feeding relationships in an
ecosystem
Food Web
What feeding relationships do you see?
Food Web and Food Chain
Create your own food web using: (arrows
always point toward what is getting energy)
grass, eagle, salmon, bear, berries, wheat,
rabbit, algae, herring, fox, mouse
Label the type of organism
Indicate one food chain based on your food
web
Ecosystem Energy Flow
Energy Pyramid: diagram that shows the
amount of energy that moves from one
feeding level to another in a food web
Trophic Levels: a feeding step of a food
web, consists of species that obtain
energy in a similar manner
Only 10% of energy gets transferred to
the next level
Energy Pyramid
Energy Pyramid
Use your food web to create an energy
pyramid
label each trophic level
Interactions
•
Types of Interactions among organisms
•
Symbiosis
•
Competition
•
Predator/Prey (Predation)
Interactions
Symbiosis: the relationship between two
organisms in which at least one benefits
Ex: bird on hippos, fleas on dogs
Interactions
Types of Symbiosis:
Commensalism
Mutualism
Parasitism
Interactions
Commensalism: one
organism benefits and
the other is not
harmed
Ex: Lichen on a
tree branch
Interactions
Mutualism: both
organisms
benefit from the
relationship
Ex: Clown fish
and sea anemone
Interactions
Parasitism: One
organism
benefits and the
other is harmed,
but not killed
Ex: mosquito
and human
Interactions
Using magazines provided by Mrs.
Peters, find pictures to represent three of
the types of interactions (each type of
symbiosis counts as a different type).
Label each picture with the type of
interaction and explain the relationship.
Interactions
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Competition:
•
When different species vie or struggle
over the same resource
•
Resources are limited by supply
•
Water, food, shelter
•
Two species with similar needs for the
same limiting resources cannot coexist in
the same place
Interactions
Interactions
•
Niche: the role of an organism in its
environment, “how it makes a living”
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How it gets food
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Habitat for survival
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All abiotic and biotic resources
Interactions
•
Niche Example
Interactions
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Predation: where one organism kills
another for its food
•
Organism getting the food is the
predator
•
Organism that is the food is the prey
Interactions
Interactions
•
Predators and prey adapt to better survive
•
Predators get better at catching prey
•
•
Speed, agility, acute senses,
weaponry, camouflage
Prey get better at avoiding being caught
•
Speed, senses, hide, mimic, smell,
coloring, shell, needles, taste
Interactions
•
Predator- Prey Simulation
Populations
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Population: all members of a species in a particular area
•
Ways to determine population size
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Direct Observation: counting all organisms in an area
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Indirect Observation: counting signs of life and estimate
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Quadrants: count a number of organisms in a small area,
then multiply by the total area
•
Mark and recapture: organisms are caught, marked,
released, then caught again to count number marked and
number unmarked
Populations
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Population Density:
the number of
individuals in a
particular area
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Population density =
# of individuals /
unit area
•
Ex: There are 20
butterflies counted in
10 m2
•
20 butterflies/10m2=
2 butterflies/m2
Population Changes
•
Populations change in
size when new members
join or when members
leave
•
Ways populations
change size:
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Births (+) and
Deaths (-)
•
Immigration (+) and
Emigration (-)
Populations
Limiting Factors: environmental factors that cause a
population to decrease
•
Types of Limiting Factors:
•
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Density Dependent: depends on population size
•
Density Independent: population size doesn’t
matter
1.
Food and water: an environment has a limited amount of
each, both are required for survival (DD)
2.
Space: the amount of area a population lives in (DD)
3.
Weather: temperatures, rainfall, hurricanes, and floods can
change the environment and not allow survival (DI)
Populations
•
Carrying Capacity:
the largest population
an area can support
due to limiting factors
•
What happens when…
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Population goes
above?
•
Populations stays
below?
Populations
•
Kaibab Deer Investigation
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History of Human Growth
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Predicting Human growth
Disturbances in
Communities