Download Ecological Pyramids - Learn District 196

Chapter 13 Principles of Ecology
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13.1 Learning Targets
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I can explain/know/understandThe levels of organization in ecology
 How observation , experimentation, & modeling are
used in ecology
 The terms: ecology ,community , ecosystem, biome
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ECOLOGY is the study of interactions
among living things
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(word comes from the Greek “oikos” which means
house)
Levels of Organization
From Smallest to Largest
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Organism: individual living thing (alligator)
Population: A group of the same species that lives in one
area (wolves in the forest)
Community: A group of different species that live together
in one area (wolves, deer, bears, ravens, moose in a forest in
the north woods)
Ecosystem: All of the organisms and the climate, soil, water,
rocks, and other non-living factors in an area (an entire
ecosystem exists within one decaying log in the forest)
Biome: Major regional or global community of organisms,
(characterized by climate and plant communities) ie: desert or
prairie
Levels of Organization
Ecological Research in a Forest
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Experimentation
Controlled experiments and data collection in the
field are difficult and challenging.
 Remember the pillbugs?
 FAQ: What are some things that make field work
so challenging and difficult?
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Ecological Research In a Forest
Observation
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Observation
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Here are some ways observational
research could be done in a forest.
 Radio tracking of wolves
 Tagging of deer
 Measuring tree growth
 Measuring pH of lakes
Ecological Research in a Forest
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Research by modeling examples
Using computer models to simulate plant or
animal populations to make predictions
 Variables can be manipulated in a computer model
(meteorologists do this all the time)
 For example: predicting how climate change and
or drought may impact large herbivores (deer &
moose) in northern Minnesota
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13.2 Biotic and Abiotic Factors
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13. 2 Learning Targets
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I can explain/know/understandRole and importance of biotic and abiotic factors in an
ecosystem
 How changing one factor in ecosystem can impact all
the others
 The terms: biotic, abiotic, biodiversity, keystone species
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Biotic Factors
Biotic factors are living things (plants,
animals, fungi, bacteria) that have a role in an
ecosystem
 FAQ: What is the role of the earthworm in a
forest ecosystem?
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Abiotic Factors
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Abiotic factors are the non-living things,
such as moisture, temperature, wind, sunlight,
and soil in an ecosystem
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FAQ: The BP Deepwater Horizon oil disaster
occurred in the Gulf of Mexico in 2011. What
abiotic factors came into play during that
disaster?
Biodiversity and Keystone Species
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Biodiversity is the variety of living things
within an ecosystem
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A Keystone species is one that has a great
impact on an ecosytem
If a keystone species is impacted, it may have a
ripple effect on other parts of an ecosystem
 A keystone species is the glue that holds an
ecosystem together
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Keystone Species
13. 3 Energy in Ecosystems
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13. 3 Learning Targets
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I can explain/know/understandThe role of producers in an ecosystem
 How producers use sunlight to obtain energy
 The terms: producer, autotroph , consumer,
heterotroph , chemosynthesis
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Producers provide energy
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Producers, also known as autotrophs, get
their energy from non-living resources, (they
make their own food)
Auto- (self)
 - troph (nourishment)
 All ecosystems depend upon producers to provide
the base
 Producers utilyze photosynthesis
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Consumers
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Consumers obtain energy by eating living or onceliving resources (plants and animals)
Consumers are also called “heterotrophs”
Hetero- (different)
Obtaining Energy
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Photosynthesis is a 2 stage process that plants use
to change sunlight, water, and CO2 into
carbohydrates (sugar)
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Chemosynthesis is the process that organisms use
to produce carbohydrates by using chemicals.
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Examples: Geothermal areas in YNP and at mid-ocean
ridge
See the next slide from Yellowstone National Park and
check out the chemosynthetic action going on.
Grand Prismatic Pool in YNP
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Notice the boardwalk
13.4 Food Chains and Food Webs
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13.4 Learning Targets
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I can explain/know/understandHow a food chain is a model that shows a sequence of
feeding relationships
 A food web is a complex network of feeding
relationships
 The terms: food chain, carnivore, herbivore,
omnivore, detritivore, decomposer, specialist,
generalist, trophic level, food web,
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Food Chain
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A food chain is a sequence that links species
by their feeding relationships
Types of Consumers
Herbivores-eat only plants (deer & moose)
 Carnivores-eat only animals (wolves &
hawks)
 Omnivores-eat both plants and animals
(bears & raccoon)
 Detritivores-eat detritus ie. Dead organic
matter
 Decomposers-break down organic matter
into simpler compounds (fungi)
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More Consumers
Florida Snail
Kite
Specialist-a consumer that feeds on one
particular organism or group of
organisms(Florida snail kite feeds only on the
apple snail)
 Generalist-consumers with a varying diet
(wolves are generalist because they feed on
many different types of prey)
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Trophic Levels-the levels of
nourishment in a food chain
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Producers-photosynthetic and chemosynthetic plants, they
provide the base upon which all consumers depend either
directly or indirectly
Primary consumers-(herbivores) they are the first trophic
level after the producers
Secondary consumers-eat the primary consumers
Tertiary consumers-eat the secondary consumers
Note: for some animals it is obvious which level they should
be placed, for others, like omnivores, they may be placed in 2
levels
Food Web
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A food web shows the complexity of a
interconnecting food chains
13.5 Cycling of Matter
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Learning Targets:
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I can Explain how water cycles through the environment
 identify and explain other elements that cycle through
ecosystems (carbon, nitrogen, oxygen, and phosphorus
cycles)
 Explain the terms: hydrologic cycle, biogeochemical
cycle
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Hydrologic (water) cycle
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Water cycle-the sun provides the energy for
water on the Earth to go from evaporation to
condensation to precipitation to collection in
bodies of water to evaporation, etc, etc, etc.
Biogeochemical cycle
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Biogeochemical cycle-the movement of a
particular chemical through the living and nonliving parts of an ecosystem
Example 1 The Oxygen Cycle
Example 2 The Carbon Cycle
Carbon is the most basic element needed for
life (organic)
 Carbon transfer occurs constantly between
plants and animals
 C can be stored in Carbon sinks (forest
contains lots of cellulose, which traps Carbon)
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Example 3 The Nitrogen Cycle
Nitrogen “fixing” bacteria put N2 back in the
soil, which then can be used by plants
 Fertilizers contain nitrates, which give crops a
boost to growth
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Example 4 The Phosphorus Cycle
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Phosphorus cycle does not include an atmosphere
component
The cycle begins with weathering of phosphorus
containing rocks
Phosphorus is common in lawn fertilizer, rain water
runoff leads to algal blooms in lakes, and fish kills
13.6
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13.6 Learning Targets
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I can explain/know/understandHow an energy pyramid show the distribution of
energy among trophic levels
 Pyramids can be used to show biomass and distribution
of organisms
 The terms: biomass, energy pyramid
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Biomass is the total dry mass of organisms in
a given area
 Pyramids are used to show energy
relationships
 Energy transfer is very inefficient, as shown in
an energy pyramid
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10% Rule
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In theory, there is no limit to the number of levels in an
ecological/energy pyramid
Only about 10% of the energy from one trophic level is
passed on to the next trophic level
Grass stores about 10% of the sunlight it receives
Cows pass on about 10% of the energy that they get
from the grass to the next level. (hamburgers)
So do the math. Only about 10% of 10% is passed on
to the burger eater (1% of original energy amount.)
The more levels there are between the producers and
the top level consumer the more energy is lost
Biomass pyramid-shows biomass levels
at different trophic levels
Pyramid of Numbers –shows actual
estimates of number of organisms
Primary Productivity
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Primary Productivity-(PP)
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PP is the amount of light energy converted to
chemical energy through photosynthesis
PP is expressed this way:
energy/meter2/year
(calories or joules per square meter per year)