Download 8.11 B: Investigate how ecosystems and populations

8.11B: Investigate how ecosystems
and populations in an ecosystem
depend on and may compete for
biotic and abiotic factors
 Make
a new title page: “Ecology”
 Glue in a new table of contents after this
title page
An
ecosystem is all the living (biotic)
and nonliving (abiotic) things that
interact in an area
 What
is the difference between an abiotic
factor and a biotic factor?
Abiotic factor are the non-living components of
the environment:
* sunlight, temperature, moisture, wind or
water currents, soil type, and nutrients
Biotic factors are the living components of the
environment:
* plants, animals, fungi, algae, and
bacteria
 Can
you always tell if it is biotic or abiotic?
 Let’s test your knowledge!
 Answer

Q1-2 now.
Work with a
partner to fill in
the Venn diagram
before time is up
 What
are your thoughts or questions now?
 Abiotic
factors are especially important to
the survival of plants that form the base of
the food web for all other organisms.
 Common Abiotic factors are:
1. Sunlight
2. Temperature
3. Water
4. Nutrients/elements
5. Space
6. soil
 These
interactions are important for survival
 Ex. Chloroplasts in a plant cell allows them to
interact with sunlight.
 Draw a Venn diagram in your notes – base it on
the picture below. What do we title the center?
 Marine
ecosystems – these organisms depend
on the amount of sunlight, water temperature,
wave action and water pressure at various
levels of the ocean.
It
is the original energy source for
almost all ecosystems
Plants capture this energy and put it
into food webs.
In order to survive, plants need
sunlight and space
Many adaptations allow plants to
survive in various amounts of light,
water, temperatures, and soil types.

Kelp adapts to salinity
level, ocean currents,
living under water


cacti adapt to lack of
water, predators, poor
soil conditions
Venus fly trap adapts to
lack of nitrogen (poor
soils in rain forests)
 Carrying
capacity – the number of individuals
that can obtain food, shelter, and water from
the environment in a given period of time
 This applies to both plants and animals
What do you know
about:
White tailed deer
overpopulation in
Texas?
Any area can only sustain a certain amount of individuals before
there is damage!
Limiting
factors are
things that prevent a
population from growing
any larger
 Food, water, light,
living space,
temperature,
competition, disease,
etc.
What
are they?
Tell me your thoughts…
 Biotic
factors also include food chains and
webs where some organism might share food
sources.
 This “sharing” isn’t actually sharing, it’s
competition for resources! We will come
back to this concept later.
There
are three major types
of interactions among
organisms in ecosystems:
Competition
Predation
Symbiosis
 Competition
occurs between
organisms when they try to make
use of the same limited resources
 Competition occurs between:
 Members of the same species
 Among species with similar
niches
How do these examples to the
right compete?
 An
organism’s particular role, or how it
fits into an ecosystem, is called its niche
 A niche is carved out when species
compete
 Many organisms are adapted to overcome
competition by resource partitioning:
 They feed at different times of day
 Or at different levels of the same tree
Resource partitioning - helps competing species
share a resource and develop a niche for
themselves in an ecosystem.
 Predation
- An interaction in which one
organism hunts and kills another for food
 The organism that does the killing – predator
 The organism that is caught - prey
 Predators
have adaptations that help them
catch and kill their prey.



Cheetahs can run very fast to catch prey
Jellyfish have poisonous tentacles to paralyze prey
Owls have big eyes to see at night
 Prey
have adaptations to help them
avoid being caught
 Camouflage
 Protective coverings
 Warning coloring
 Mimicry
 False coloring
 Predation
can have a major effect on
population size
 If predators are very effective, the
result is a decrease in the prey
population
 In turn, a decrease in the prey
population will result in a decrease in
the predator population
A close relationship between two
different species that benefits at
least one of the species
 There are three types of
symbiotic relationships:

Mutualism
 Commensalism
 Parasitism


Benefits of Symbiosis:





Food
Transportation
Cleaning
Protection/Shelter
Reproduction
 One
species benefits (+) and
the other is unaffected (0)
 Commensalism means “at
the table together”
Barnacles and whales
 Both
species benefit
 Giraffes and Oxpeckers
 One
living thing gains (+)
considerably at the expense
(-) of the other


Host – the organism that the
parasite lives on or in – it will
be harmed
Parasite – the organism that
benefits
 Maggots
in My Head
Reef Symbiosis
 In
symbiosis, at least one member of the
pair benefits from the relationship.
Commensalism
Mutualism
Parasitism
One benefits

One benefits

One benefits

One is
unaffected

Also benefits One is harmed


Even
humans create personal
territories, even temporary ones
in order to have enough space.
Humans tend to space themselves
out when they are close to others
 They establish what we might
call “personal territories”
Even in a temporary spot, people (animals) make space.
It makes us feel more secure and protected
Think of the classroom as your ecosystem. The edges of
the room define your habitat. Calculate the area of the
habitat (classroom).
Area of Room (m2) = Width (m) X Length (m)
Determine the number of students that live in the habitat
(in the classroom). Divide the area of the room into equal
amounts of space for each student.
Personal Space (m2) =
Area of Room (m2)
Number of Students
Think of the classroom as your ecosystem. The edges of
the room define your habitat. Calculate the area of the
habitat (classroom).
Area of Room (m2) = Width (m) X Length (m)
1. Use meter sticks to measure the length (1/2 of
the groups do this).
2. The other groups measure the width.
3. We will take the average for our calculations.
How many students do we have?
Determine the number of students that live in the habitat
(in the classroom). Divide the area of the room into equal
amounts of space for each student.
Personal Space (m2) =
Area of Room (m2)
Number of Students
How
big is the room?
How many students are there?
So how much personal space did
everyone get?
   
   
It might look
like this
   
   
   
   