Transcript Limiting Factors Period 6

Limiting Factors
Ecosystems
SC.912.L.17.5
ESSENTIAL QUESTION:
How do abiotic (physical)
limiting factors affect growth
and survival in an ecosystem ?
Let’s suppose….

We have two mice…:
and they
produce the
standard 56
“pups” (baby
mice) each
year.
and each of
these mice goes
on to have 56
babies each
year….
Soon…..

We’d be over-run with mice on the planet!!
Why doesn’t this occur?
Limiting Factors

A limiting factor
is an abiotic or
biotic factor that
restricts the
number of
individuals in a
population.
ARTICLE: Limiting Factors

Read your assigned
section as a group.

Share what you
learned about
limiting factors with
the class
JIGSAW
ACTIVITY
VOCABULARY
Term
limiting factor
population
ecosystem
predator
prey
habitat
species
carrying capacity
resource
degradation
reproduction
Definition
Visual
Limiting Factors

1.
Limiting factors can
include:
Competitors
Limiting Factors

1.
2.
Limiting factors can
include:
Competitors
Disease and
parasites
Limiting Factors

1.
2.
3.
Limiting factors can
include:
Competitors
Disease and
parasites
Weather
Limiting Factors

1.
2.
3.
4.
Limiting factors can
include:
Competitors
Disease and
parasites
Weather
Fires
Limiting Factors

1.
2.
3.
4.
5.
Limiting factors can
include:
Competitors
Disease and
parasites
Weather
Fires
Available habitat
Limiting Factors

1.
2.
3.
4.
5.
6.
Limiting factors can
include:
Competitors
Disease and
parasites
Weather
Fires
Available habitat
Predators
Competitors-organisms both
cooperate and compete
•Birds of prey
•Live in forests on
the edge of fields
•Eat mice and
other rodents
•Nest in trees
Red-Tailed Hawk
Barred Owl
Disease and Parasites
 Diseases
and
parasites can
be dependent
on population
size and
habitat
Weather
Storms
Drought
Flooding
Heat/cold
Fires

Fires lead to
succession which
is a predictable
change in the
community over
time.
Available Habitat
 Human
activities play a
large role
 Development,
damming
rivers, clear
cutting forests.
HOT LAB: Limiting Factors
Problem Statement:

Part A: How will resource availability
affect the population of a species in an
ecosystem?
Independent Variable:_________________
Dependent Variable: __________________
Hypothesis: If ________ then ______.
Part A:
DATA: Effects of Resources
on Deer Population
Year (round)
Deer Population (#)
# Resources
0
7
21
1
14
14
2
20
8
3
18
11
4
22
7
5
13
16
6
28
1
7
2
27
HOT LAB: Limiting Factors
Problem Statement:

Part B: How will a density-independent
limiting factor (flood or drought) affects
the population of species in an
ecosystem?
Independent Variable:_________________
Dependent Variable: __________________
Hypothesis: If ________ then ______.
Part B:
DATA: Effects of Natural
Disturbances on Deer Population
Year (round)
Deer Population (#)
0
7
1
14
2
24
3
12
4
14
5
28
6
2
7
4
8
8
9
4
Resources (#)
Events
21
14
5
17
Flood
15
1
27
25
21
25
drought
HOT LAB: Limiting Factors
Problem Statement:

Part C: How will a density-dependent
limiting factor (predator) affect the
population of species in an ecosystem?
Hypothesis: If ________ then ______.
Part C:
DATA: Predation
Year (round)
Deer Population (#)
Predator (#)
0
7
1
1
8
4
2
6
6
3
6
1
4
8
2
5
6
7
ANALYSIS QUESTIONS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
List the basic needs of animals.
Describe the relationship between resource availability and population growth
or decline.
Describe reasons for the fluctuation of the population.
Define “limiting factors” and provide three examples.
What is the carrying capacity for the deer population according to your graph?
Once the deer population goes significantly above carrying capacity, describe
what happens to the deer population in the years following.
How did the introduction of a predator affect the deer population in terms of
population size and deer behavior?
What was the peak population for the deer population when there were no
predators? What happened after the peak? Why?
How might this “simulation” differ from the real relationship between deer and
their environment? Write at least two differences and explain.
How do you think this “simulation” game differs from real predator-prey
relationships? Explain.
Predators

As the prey
population
increases, the
predator population
increases. As the
prey population
decreases, then so
does the predator
population.
Example: Lynx and Hare:
VIDEO: How the wolves
changed the river?