Transcript Ch. 2 - Ecology

Ch. 18-22 - Ecology
Organisms and their environment
• What is ecology?
• the study of the interactions that takes
place between an organism and their
environment
Ecology
• Biosphere:
• Portion of the Earth that supports
living things
• Ranges from high in the atmosphere
to deep in the ocean
• If the Earth were an apple, that
would be the thickness of the peel!
What makes up the biosphere?
• Biotic factors
•
All living things that live in an environment
•
plants and animals
•
Depend directly or indirectly for food, shelter, reproduction, or protection
• Abiotic factors
•
All nonliving parts of an organisms environment
•
air, temperature, moisture, light, soil
•
how do these thing affect the organisms life cycle
Organization
• The living world is organized according
to different levels
1. The organism
2. Populations
3. Communities
4. Ecosystems
Organization
1. The organism
• Lowest level of organization
• Deals only with the individual plant
or animal and nothing else
Organization
2. Population
•
A group of organisms of the same species that
interbreed and live in the same area at the same
time
•
Share resources - determines size and distance they
live
•
Compete for food, water, mates, and other resources
•
Some species have different forms to enable less
competition
•
tadpoles vs. frogs - totally different food
requirements
Organization
3. Community
• Populations that interact with each other in
a certain area at a certain time
• Contains many different organisms of
different species
• Interdependent - changes
in one will affect the others!
Organization
4. Ecosystem
• ALL living populations and nonliving things
• Terrestrial ecosystems - located on land
(forest, meadows, rotting logs)
•
Aquatic ecosystems - fresh and salt
water (ponds, streams, oceans)
• saltwater also called marine
ecosystems and make up 70% of the
Earths surface!
Vocab
1. Ecology
2. Abiotic factor
3. Biotic factor
4. Community
5. Population
A. The non living parts of the
environment
B. A group of 2 or more
different species living in
the same area
C. The study of organisms
and the area in which they
live
D. A group of organisms of
the same species
E. Animals, plants, and fungi
Organisms in Ecosystems
•
Where do you live? That is your habitat
•
habitat - place where an organism lives its life
•
•
Can change over time
What else is in your habitat? Do the other things
use the resources that same way you do?
•
niche - strategies and adaptations and
species uses (how it gets food, where it gets
shelter, where it reproduces)
•
a habitat contains many niches
Symbiosis
• Most species do not battle for survival.
Most survive because of the
relationships between other species
• Symbiosis - close, permanent
association between organisms of
different species
Symbiosis
• Three types of symbiosis
1. Mutualism
2. Commensalism
3. Parasitism
Symbiosis
1. Mutualism
• Relationship in which both species
benefit
• Example - ants and acacia trees
Symbiosis
1. Commensalism
• Relationship when one species
benefits and the other has no effect
• Example - Spanish moss
Symbiosis
3. Parasitism
• Relationship when one member of a
species benefits at the expense of
the other (called the host)
• If the host dies, the parasite dies
Vocab check
1. Parasitism
2. Mutualism
3. Commensalism
A. All living and nonliving
things in an
environment
B. One species benefits
and one has no effect
C. Both species benefit
4. Ecosystem
5. Organism
D. Anything that is alive
E. One species benefits
at the others expense
Nutrition and Energy
• ALL energy for ALL life comes from one
place :
Nutrition and Energy
• The Produces
• Autotrophs - organism that uses light
energy to make energy for life functions
• Examples: grass and trees, algae
Nutrition and Energy
• The Consumers
• Heterotrophs - organism that cannot make
its own food and feeds on other organisms
• Can feed on autotrophs,
heterotrophs, or both
Heterotrophs
•
Heterotrophs that feed only on plants - HERBIVORE
•
•
Heterotrophs that eat other heterotrophs CARNIVORES
•
•
lions, alligator, venus fly trap
Heterotrophs that do not kill for food but eat other
animals that have already died - SCAVENGERS
•
•
rabbits, grasshoppers, squirrels
vultures
Heterotrophs that eat animals and plant materials OMNIVORES
•
humans, raccoons, bears
Decomposers
• Some organisms are called
decomposers
• decomposer - break down and
release nutrients from dead
organisms
• fungi and bacteria
Flow of Energy
•
Energy flows from producers to consumers
•
Simplest model of energy flow is called a food chain
•
how matter and energy move through an
ecosystem
•
drawn using arrows to indicate energy transfer
from autotroph to heterotroph to decomposers
•
•
Berries
Mice
Black bear
energy decreases in each transfer
Flow of Energy
• Berries
Mice
Black bear
Fungi
• each link of the chain represents one trophic
level
• a feeding step
• A food chain only represents one possible
route of energy
Flow of Energy
• A food chain is easy to study, but does
not show the complexity that exists
• To show the relationships that exist
between various organisms in the
community we use a model called a
food web
Ecological pyramids
• Another model of energy flow in an
ecosystem
• Bottom are the autotrophs
• Each level up is a trophic level
Cycles in Nature
• The matter on Earth has a set amount. It is
not endless, but limited.
• Matter is always recycled, never lost
• Cycles:
• Water cycle
• Carbon cycle
• Nitrogen cycle
• Phosphorous cycle
Cycles in Nature
• Water Cycle
• We recycle water all the time
• drink water - breathe
out vapor / urinate
Cycles in Nature
• Carbon cycle
• Carbon is the molecule of life
• During photosynthesis sunlight and
CO2 are converted into carbon
molecules (like sugar) for energy
Cycles in Nature
• Carbon cycle
Cycles in Nature
•
Nitrogen cycle
•
Nitrogen in the soil is used to make important
molecules like proteins for plants
•
animals then eat the plants and convert the
plant N into animal proteins (nitrogen)
•
you eat this and it transfers into human
proteins
•
your waste (urine) takes the nitrogen out of
your body and back to the ground where the
cycle renews
Cycles in Nature
• Phosphorous cycle
• used for energy in your body
• comes from the soil to plants
• you eat plants and when animals die,
the body decomposes back into the
soil
Succession: Changes over Time
• Succession
• The orderly, natural changes and species
replacements that take place in the
communities of an ecosystem
• Occurs in STAGES
• Difficult to observe because it can take
decades or centuries for communities to
succeed
Primary Succession
• The colonization of barren land by
communities of organisms
• Takes place on land where there are no
LIVING ORGANISMS
• Example:
• Volcano
Primary Succession
• Pioneer species
• First species to appear on new, barren land
• Example:
• Lichen – group of small organisms
Primary Succession – the process…
• Pioneer species dies….
• Provides 1st stage of soil….
• New soil develops……
• Small weedy plants develop…
• New organisms move in…
• Area grows in size….
Primary Succession
• After some time, primary succession slows
down and becomes stable
• Climax community
• Mature, stable community with little or no
change
• Change is dynamic – balances out
• May last for hundreds of years
Primary Succession
Stages
Secondary Succession
• Sequence of changes that takes place after
an existing community is severely disrupted
in some way
• i.e. A natural disaster
• Community of organisms inhabiting an area
gradually changes
• Occurs in areas that previously contained
LIFE + land still contains soil
Secondary Succession
• May take less time to reach climax
community
• Example:
• Yellowstone National Park (1988)
Secondary Succession
Stages