Tuesday 5-7-13
• Do Now: Read MSP book
standard LS2
• (Life Science #2)
Content Standard: 6-8 LS2A
An ecosystem consists of all the
populations living within a
specific area and the nonliving
factors they interact with. One
geographical area may contain
many ecosystems.
Content Standard: 6-8 LS2A
Students are expected to:
• Explain that an ecosystem is a defined
area that contains populations of
organisms and nonliving factors.
• Give examples of ecosystems (e.g.,
Olympic National Forest, Puget
Sound, one square foot of lawn) and
describe their boundaries and
contents.
LS2A: Ecosystems
• A biological community of
interacting organisms and their
physical environment
• Or:
• An ecosystem is formed by the
interactions between all living
and non-living things
LS2A Ecosystems:
Fundamental Characteristics
• Structure: (Living & Nonliving)
• Process: (Interaction)
– Energy flow
– Cycling of matter (chemicals)
• Change: Dynamic (not static)
Video: Mt St Helens 3:22
Content Standard: 6-8 LS2B
Energy flows through an
ecosystem from producers
(plants) to consumers to
decomposers. These
relationships can be shown for
specific populations in a food
web.
Content Standard: 6-8 LS2B
Students are expected to:
• Analyze the flow of energy in a
local ecosystem, and draw a
labeled food web showing the
relationships among all of the
ecosystem's plant and animal
populations.
Trophic level: All the organisms that are
the same number of food-chain steps
from the primary source of energy
Modified from: General Ecology, by David T. Krome
Energy Pyramid
• Bottom
–greatest energy
• Top
–least energy
Source:
corpuschristiisd.org/user_files
/91702/Ecosystem.ppt
Food Chains
• Producers – Consumers Decomposers
• One ecosystem will contain
many food chains
• Food chains show where
energy is transferred and not
who eats who.
Example of a Food Chain
Food web of a hot spring
© 2003 John Wiley and Sons Publishers
Video
Food Webs 2:00
Content Standard: 6-8 LS2C
The major source of energy for
ecosystems on Earth's surface is
sunlight. Producers transform the
energy of sunlight into the chemical
energy of food through photosynthesis.
This food energy is used by plants, and
all other organisms to carry on life
processes. Nearly all organisms on the
surface of Earth depend on this energy
source.
Content Standard: 6-8 LS2C
Students are expected to:
• Explain how energy from the Sun is
transformed through photosynthesis to
produce chemical energy in food.
• Explain that plants are the only
organisms that make their own food.
Animals cannot survive without plants
because animals get food by eating
plants or other animals that eat plants.
Chloroplast structure
Chloroplasts are the organelles
in plant cells that contain the
pigment CHLOROPHYLL.
OVERVIEW OF
PHOTOSYNTHESIS
SUNLIGHT PROVIDES
THE ENERGY
FOR PHOTOSYNTHESIS
PLANTS MAKE GLUCOSE
AND OXYGEN
PLANTS TAKE IN
CO2 AND H2O
Photosynthesis
How does it work?
TAKE IN
water
carbon dioxide
USE
light
PLANTS
(producers)
chlorophyll
MAKE
oxygen
glucose
Close up on a plant cell:
Cell wall
Cell
membrane
Large
vacuole
Chloroplasts
(containing
chlorophyll)
Nucleus
Cytoplasm
Video
Photosynthesis Bill Nye 2:10
Photosynthesis song 3:11
Content Standard: 6-8 LS2D
Ecosystems are continuously changing.
Causes of these changes include
nonliving factors such as the amount
of light, range of temperatures, and
availability of water, as well as living
factors such as the disappearance of
different species through disease,
predation, habitat destruction and
overuse of resources or the
introduction of new species.
Content Standard: 6-8 LS2D
Students are expected to:
• Predict what may happen to an
ecosystem if nonliving factors
change (e.g., the amount of
light, range of temperatures, or
availability of water or habitat),
or if one or more populations
are removed from or added to
the ecosystem.
Primary Succession
• Never had a
community
living within it
• Example: New
lava or rock
from a volcano
that makes a
new island.
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Primary Succession
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The Circle of Life in
Secondary Succession
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Natural vs. Managed
May 18, 1980
• Where can we study ecological
succession in Washington
State?
How Ecosystems Change 3:19
Content Standard: 6-8 LS2E
Investigations of environmental
issues should uncover factors
causing the problem and
relevant scientific concepts
and findings that may inform
an analysis of different ways to
address the issue.
Content Standard: 6-8 LS2E
Students are expected to:
• Investigate a local environmental issue
by defining the problem, researching
possible causative factors,
understanding the underlying science,
and evaluating the benefits and risks of
alternative solutions.
• Identify resource uses that reduce the
capacity of ecosystems to support
various populations (e.g., use of
pesticides, construction).
LS2E Videos
Dangers of Genetic Engineering
4:03
Mardon Skipper Washington 2:00
Exit
1.What is the LT?
2.What did I learn?
3.How did I learn it the best?
4.Where can I learn more?
Two types of Ecological
Succession
• Primary Succession: To life
previously existed.
• Secondary Succession:
Follows a disturbance in an
ecosystem.
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Secondary Succession
• Habitat partially destroyed
• Fire, Tornado, landslide,
volcano.
• Soil is already in place
• 5X – 10 X faster than primary
succession.
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Does Ecological Succession
Ever Stop?
• Any ecosystem, no matter how
inherently stable and persistent,
could be subject to massive
external disruptive forces (like
fires and storms).
• Never absolutely accurate to say
that succession has stopped.
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