Download Energy Flow in Ecosystems

Biology 1
Ecology
Name: ____________________________
Period: ________
Matter and Energy Flow through the biosphere and through
ecosystems via biotic and abiotic processes. Organisms both
cooperate and compete in ecosystems, and these interrelationships
and interdependencies lead to ecosystem stability.
The Guiding Questions
1. How does matter and energy flow through an ecosystem?
2. What are some common relationships between organisms in
ecosystem?
3. How do humans modify ecosystems?
4. How can people thoughtfully manage ecosystem resources
they are sustainable?
an
so
Learning Outcomes
By the end of this topic, you should be able to:
 explain the terms population, community, habitat, ecosystem, biome, biosphere and give
relevant examples
 describe examples of variation among species and within species
 identify examples of niches and describe the role of variation in helping closely related
living things to survive and in the same ecosystem
 describe biotic and abiotic factors in an ecosystem and explain their affects on one
another
 Identify and give examples of relationships in ecosystems: predation, herbivory, symbiosis,
mutualism, commensalism, parasitism
 Use quadrats to measure biotic factors in a habitat, and analyze data using t-tests
 Explain and construct food chains, food webs, and trophic level diagrams
 Describe the transfer of matter and energy along a food chain, including the 10% rule
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 Describe the global effects of tropical rainforest deforestation, including leaching, soil
erosion, disturbance of the water cycle and balance of atmospheric oxygen and carbon
dioxide, loss of habitat and loss of biodiversity
Vocabulary Pages
By the end of this topic, you should be able to define and correctly use the following terms:
Get a head start and write in the definitions for all the terms.
Biotic
Abiotic
Population
Community
Habitat
ecosystem
Biome
Biosphere
Niche
Species
Predation
Herbivory
Mutualism
Commensalism
Parasitism
Symbiosis
Quadrat
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Ecology
t-test
Food chain
Food Web
Trophic Level Diagrams
Producer
Consumer
Primary consumer
Secondary consumer
Tertiary consumer
Decomposer
Saprotrophs
Detritivores
Biodiversity
Leaching
Ecological footprint
Sustainability
Eco-Tipping Points
Autotroph
Heterotroph
Omnivore
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Ecology
Define the following:
Ecology:
The study of the
interactions btn living orgs
and between living
organism their env’t. led
Biotic Factors:
The living part of an
environment; (organisms
and their interactions)
Abiotic Factors:
The non-living part of an
environment; (water, rocks
/ soil / air)
Label the biotic and abiotic factors of this grassland ecosystem:
Definition of SPECIES:
The term is the most specific ranking in the taxonomy of a living organism (Kingdom, phylum,
class, order, family, genus and then species). Organisms of the same species are similar in
characteristics and can interbreed to produce fertile offspring.
Distinguish between habitat and niche. Give an example for a particular organism.
Habitat – the area where an organism lives. E.g. a tadpole lives in a pond
Niche – the role that an organism plays in its ecosystem.
The specific set of conditions surrounding an organism is it habitat. Each species in an
ecosystem defines its activities in specific ways such as:
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
where it lives

what feeds on it

when and how it reproduces

when it feeds and where

what it feeds on

climatic conditions it favours
The functional role of each individual is termed its ecological niche. No two niches within a
given ecosystem are identical and no 2 organisms can occupy exactly the same exact niche, but
there can be overlap.
. For example:
Two closely related warblers, the cerulean warbler and the black-throated warbler, live
in the mixed forests of the northern U.S. Both are incest eaters, and they may nest very
near one another but the cerulean warbler searches for insects in the upper leaves of the
deciduous trees (trees that lose their leaves in winter), whereas the black-throated
warbler feeds only in the upper branches of the hemlocks (coniferous; trees with needles
as leaves).
How is an animal’s niche related to variation and adaptation?
Every living organism is adapted to the conditions in which it lives. For example: Desert plants have
thick, waxy cuticles in order to help reflect sunlight. They also have spikes in order to protect the
plant from predators.
Can you think of another example? Include it here.
The effects of an abiotic factor on a biotic factor.
Organisms will adapt in order to survive their abiotic conditions. The individuals that are better
adapted to the conditions will be the ones that are healthier and stronger and will be the ones that
breed and pass along their genes (natural selection and survival of the fittest).
Natural Selection and adaptive traits (the bird game)
Levels of Life
Organism (any single living thing)
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 ____________________(members of same species living in one place)
Ecology
 ____________________ (different populations living in an area)
 __________________ (community living in a similar habitat)
 __________________ (ecosystems covering wide areas)
types of biomes World Biomes Map
 ___________________ (all the living and non-living things on earth)
Population Ecology
Population Ecology: the interactions within one population, especially relating to population size.
Factors that increase population size:
size:
Factors that decrease population
What are some factors that would influence natality and mortality rates? Immigration and emigration?
For animals other than humans
For Humans
???? are all the things available to living organisms that they used / need to survive. For example:
land, forests, mineral deposits, water, food, clean air, etc.
????? (environmental resistance):
These are things that prevent a population from growing any larger. For example, there is enough
grass to feed 20 deer, enough water to support 50 deer and enough space for 75 deer.
The limiting factor in this case is the food supply so the population of deer will be kept in check.
????? = the maximum population that an environment can sustainably support.
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Population Graphs: From the graph to the left, discuss what is
happening in terms of amount of available resources and
population size.
1.) Growth (Exponential) Phase – ???
2.) Transitional (Log) Phase – ???
3.) Stationary (Plateau) Phase – ????.
Community Interactions:
Name of Interaction
Type of Interaction
Examples
Mutualism
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Commensalism
Parasitism
amoeba eating
Predation
Competition
Energy Flow in Ecosystems
Trophic Levels: The level at which an organism obtains energy (its food).
Producers: Define the prefix and base word of the term “autotroph” and discuss their role in nature.
Auto = ????
troph = ????
Autotrophs are ?????
There are 2 types of autotrophs; ???? (uses light) and ?????? (uses chemicals)
????? are ????; they capture light energy from the sun and through a series of amazing reactions they
produce sugars that they will use as their food source.
6CO2 + 6H2O + Sunlight + Chlorophyll
C6H12O6 + 6O2
In words: ??????????????????
???? (uses chemicals) to synthesize / make their own food. Video: Chemoautotrphs
Consumers: Define the prefix and base word of the term “heterotroph” and discuss their role in nature.
Hetero = ????
troph = ????
Heterotrophs ?????
Define these examples of consumers in terms of how they obtain their food:
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Herbivore – ????
Carnivore – ?????
Decomposer – ??????
To the left, define (in terms of how they obtain their energy); To the right, list the trophic level
Special Heterotrophs: The Decomposers (nutrient recyclers!)
How they get their energy
Examples
Detritivores
Saprotrophs
Fill in the circles on the diagram below
(Use the diagram in your paper packet)
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Food Chains vs Food Webs
What is the definition of a food chain? What does it show?
Food chain ???
These show the sequence by which energy in the form of food passes from a plant to an animal
and then to another animal. Each of these levels is called a trophic level. Trophic means feeding.
leaf ------ > snail ------ > blackbird (3 energy levels)
leaf ----- > aphid ----- > ladybug ----- > small bird ----- > large bird (5 levels)
What do the arrows on the
diagram represent? ???
Food chains are usually short because as the energy is passed along the chain each organism uses
some of it. Also, at every level some of the initial energy (from the sun) is lost to the chain. It is
lost through waste, death and the production of heat. So the further along the chain you go, the
less initial energy there is.
The loss of energy along the chain limits the length to 5 levels (rarely more this). There is just
not enough energy left to supply the next link.
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Feeding at different trophic levels
algae ---- > human
humans are feeding at the ???
- are ???
- are ???
algae ----- > prawn ----- > human
at the ???
- are ???
- are ???
algae ----- > prawn ----- > fish ----- > human
at the ???
- are ???
- are ???
Many living organisms consume both plant and animal matter; these animals are called
omnivores
How does a food web differ from a food chain? What does it show that a chain doesn’t?
Food Webs ?????
Handout: Food Web analysis
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Energy Transfer in Ecosystems
On average, how much
energy is transferred on to
the next trophic level?
~???%
Notice what’s happening at the
first trophic level. What
percentage of light energy can
plants capture through
photosynthesis?
How much more food would the world have if we all ate one trophic level down?
How is this an argument for becoming a vegetarian??
A law of physics says that energy cannot be created nor destroyed it is transferred or
transformed. So why doesn't all the energy from one trophic level get transferred to the next
trophic level? Where does the ‘lost’ energy go?
Why can only 10% of energy be transferred to the next trophic level?
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