Transcript Energy in Ecosystems

Energy in
Ecosystems
Review
What is a Food Web?
• a group of food chains
showing all of the
feeding relationships
in an ecosystem.
All Food Webs:
• Trophic
level — a
• Original Energy (SUN)
layer in the feeding
• Producers
relationship
of an
• Consumers one link in
ecosystem,
• Decomposers
the
food chain/web.
So, all producers are
at the same trophic
level and all primary
consumers are at the
next trophic level.
• Soil
• Biomass
— total
• Arrows showing energy
amount
of organic
flow!
material present in a
trophic level.
Organic = is
currently living or
lived in the past
Energy/Ecological Pyramids
http://www.vtaide.com/png/foodchains.htm
http://www.earthforce.org/files/1284_image2_Energy_Pyramid_for_
Galvbay.jpg
• Another way to look at
trophic levels.
• a diagram showing the
relative amounts of
energy/biomass in the
different trophic levels.
• Lowest trophic levels
are at the bottom:
Producers have the
greatest biomass.
Example of an Energy Pyramid
1 MAN
MAN
0.1%
10%
100 %
of the
sun’s
energy
FOX
1%
10%
10%
RABBIT
Rabbit
90%
Energy Lost
during
conversion
to heat,
waste….
90%
10%
Grass
90%
10 FOXES
100
RABBITS
1000
Bunches of
GRASS
- The decreasing size of the pyramid shows
that each level of the pyramid has a smaller
and smaller number of those organisms.
Carrying Capacity:
• The maximum population a
community can tolerate for
extended periods of time.
Population:
How many of a
specific species
can live in an
area?
Community =
the plants and
animals found
in an area
An extended period
of time … the
environment remains
healthy and future
generations of organisms
are able to continue to live
within the community
• Look at this
picture
called “The
Full Bucket”
• How does
this
illustration
explain this
concept?
What causes populations to spill
over (die or leave)?
• Carrying Capacity is usually due to Abiotic
Factors
Abiotic Factors = nonliving characteristics of the
environment.
For example:
-Sunlight
-Moisture
-Space
-Pollution
-Landscape/Terrain
What is this illustration
trying to tell you about
carrying capacity?
This ecosystem is
overflowing
What are some of the
reasons this ecosystem
is “spilling over.”
This is what limits a population from becoming too large?
Limiting Factors:
• Anything that keeps a population from
over-growing the resources available.
• Consider how changing the factors that affect
carrying capacity can alter the population size
of a species.
Predation
Disease
Floods
Accidents
Drought
Fire
Hunting
Pollution
Shade
Parasites
Storms
Starvation
Habitat Loss
New Predator/Prey Website
•http://www.shodor.org/
interactivate/activities/
RabbitsAndWolves/