8.11b: investigate how ecosystems and populations … is the difference between an abiotic factor...
TRANSCRIPT
8.11B: Investigate how ecosystems
and populations in an ecosystem
depend on and may compete for
biotic and abiotic factors
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
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.
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
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”
Area of Room (m2) = Width (m) X Length (m)
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).
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.
Area of Room (m2) = Width (m) X Length (m)
Think of the classroom as your ecosystem. The edges of the room define your habitat. Calculate the area of the habitat (classroom).
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.
Personal Space (m2) =Area of Room (m2)
Number of Students
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.
How many students do we have?