Download Food webs Shows the complex network of feeding relationships and

What does Ecology study?
Ecology
Eco- oikos - house
Is the study of the
interactions among
living things and their
environment
Levels of Organization
• Organism
– Individual living thing
• Population
– All the members of the same
species in a given area and time
• Community
– All the different populations in
the same area at a given time
• Ecosystem
– Includes all the living and
nonliving factors in a given area
• Biome
– Major region community of
organisms characterized by
climatic conditions
• Biosphere
– The area where living things can
inhabit
An Ecosystem consists of all the living and nonliving factors in a given area
Biotic
– Living things or
influences from
living things
– Competition
– Predation
Use the diagram above to list the factors
Abiotic
– Non-living factors
– Weather, humidity,
sunlight, soil,
sound, wind…
Biotic
Abiotic
What is meant by Biodiversity?
Biodiversity
•
The variety of living things
in an ecosystem.
•
Highest in the rainforest
• Only covers 7% of earth but
contains 50% of the biodiversity of
species
•
•
Lowest in the tundra or
desert
Depends on factors such
as moisture and
temperature.
Is there an species that has an unusually large effect on its ecosystem?
Keystone species holds
together an ecosystem
Beavers with their
dams
Confers in the taiga
Should the keystone
species disappear,
there would be major
changes to the
ecosystem
An ecological food pyramid shows the
flow of energy in an ecosystem
Consumer
Heterotroph
Autotroph
Producer
Most of the energy is
found in the
producers
Herbivores come
next
Least amount of
energy in the
carnivores and the
top level
consumers
A food chain is a sequence of feeding that links
species by their feeding relationships.
Producer
Plant
Producer
Plant
1st Consumer
Herbivore
1st Consumer
Herbivore
2nd Top consumer
Carnivore
Top consumer
Carnivore
2nd Consumer
3rd level consumer Top consumer
Carnivores …………………………………………….
This diagram below shows the full food chain for bears during salmon season when the
bears are carnivorous, starting with algae at the base of the salmon food chain. If a human
eats the bear, then he/she is eating at 1 step higher in the food chain than the bear.
Identify each level.
Put these organisms into a food web
And in the end, where does all the energy end up?
The decomposers,
which are fungus &
bacteria, recycle
the nutrients in
dead matter and
return them to the
ecosystem
Is a food chain a realistic representation of food
relationships in an ecosystem?
What else may eat the grass, the grasshopper, the
frog, or the snake?
Food webs
Shows the complex network of
feeding relationships and the flow
of energy within and sometimes,
beyond the ecosystem
Examine the food web shown below.
Identify the various trophic levels
Producers
Primary Consumers
Secondary Consumers
Tertiary Consumers
Top Consumers
Just as the energy needs to be cycled through the living
organisms in an ecosystem, so do the non-living factors such
as O2, CO2, Water and Nitrogen
Biogeochemical cycles move particular chemicals
or elements through the biotic and abiotic parts
of the ecosystem.
• Water Cycle
– Cycles water through precipitation, condensation,
runoff and evaporation
• Carbon Cycle
– Cycles CO2 and O2 through photosynthesis and
respiration
• Nitrogen Cycle
– Cycles atmospheric nitrogen through bacteria in the
soil to the plants and then to the animals
Water Cycle
Cycles water through condensation, precipitation,
evaporation, runoff and transpiration
precipitation
condensation
transpiration
evaporation
surface
runoff
lake
water storage
in ocean
groundwater
Carbon/Oxygen Cycle
Cycles through respiration (CO2 in) and photosynthesis
(CO2 out)
Carbon Cycle
Cycles between CO2 produced by respiration & combustion, O2
produced by photosynthesis,
carbon
dioxide
in air
respiration
combustion
photosynthesis
respiration
decomposition
of organisms
fossil fuels
photosynthesis
carbon dioxide
dissolved in water
Nitrogen Cycle
Bacteria take atmospheric nitrogen (N2), convert it to a form which
plants can use (ammonium). They also decompose dead matter and
then return the N2 to the atmosphere.
nitrogen in
atmosphere
animals
plant
nitrates
nitrogen-fixing
bacteria in
roots
decomposers
nitrifying
bacteria
ammonification
nitrogen-fixing
bacteria in soil
nitrites
ammonium
nitrifying
bacteria
denitrifying
bacteria
Cycling of Matter--Nitrogen
Waste, Atmospheric N2, Plants, Bacteria, Denitrification, Soil N,
Nitrogen fixation, Decomposition
Atmospheric N2
bacteria
waste
decomposition
denitrification
Soil N
plants
Nitrogen
fixation
What happens to all the energy as it flows through each
trophic level? Is all of it transferred?
Observe the energy
pyramid shown below.
Which trophic level will
contain the most
collective energy
___________________
Which will have the least
amount of collective
energy stored in it?
_____________________
How is energy lost at each trophic level? Think of a word you
learned at the start of the school year when we discussed the
characteristics of all living things
METABOLISM!!!
– Organisms use the energy to keep it going
– Moving
– Digesting
– Absorbing
– Reproducing
Most of the energy is lost as heat!!!!
Only 10% of the energy is actually transferred to
the next trophic level
If only 10% is transferred
and 90% is lost, which
organisms on this food
pyramid would one be
better off eating?
Most of the energy is in
the producers.
Think of how much food
the lion must eat to
keep up its
metabolism!!!