Transcript Energy Transfer through an Ecosystem

Ecology
The study of interactions among
organisms and between organisms
and their environment
Ecology Focus ?
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How do organisms contribute to the
functioning of the environment as a system?
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How is energy captured, stored, and
transferred in an ecosystem?
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What specific impacts do humans have
on the environment?
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Abiotic –
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Nonliving factors of an ecosystem
Climate, land conditions, etc.
Biotic
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Living factors of an ecosystem
Plants, animals, fungi, etc
Hierarchy of Life
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Complexity & levels of organization:
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Species / Organism
Population
Community
Ecosystem / Biome
Biosphere
Energy Transfer through an
Ecosystem
All organisms need energy to carry
out their life functions: growth,
movement, reproduction, etc.
Energy flows through the
TROPHIC Levels of a Food Chain
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Sun - primary source of energy to the
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Producer (autotrophs)– capture sunlight &
convert it to a usable form (plant material)
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to the heterotrophs
Primary Consumers – feed on producers
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to the
to the
Secondary Consumers – feed on primary
consumers
Energy Flows through each Trophic
Level or Step of the Food Chain
Food Web- a more accurate model of the
complex network of feeding relationships
among the various organisms in an ecosystem
Pyramid Models
Energy Transfer through Trophic
Levels is NOT 100% efficient
Pyramid of Energy Transfer
10%
Efficient
transfer
at each
level
Biomass organic matter in an ecosystem
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Gross Primary Productivity
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Rate at which producers capture energy
Net Primary Productivity
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Rate of biomass accumulation into plant
material
photosynthesis – respiration in plants
Varies by light, temperature,
precipitation, availability of nutrients
Pyramid of Biomass
Approximate dry weight of
biomass at each level
Pyramid of Numbers
Approximate number of
organisms supported at each level
Ecosystem Recycling
Water, Carbon,and Nitrogen Travel
Through a Biogeochemical Cycle to
be recycled and reused
The Law of Conservation of
Matter & Energy
Matter and energy are neither
created nor destroyed but only
change in form
The Water Cycle
New terms you should know…
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Precipitation –water vapor converting to
liquid. Ex: Rain, snow, sleet, hail, fog
Evaporation – liquid water converting to water
vapor in the atmosphere
Transpiration – releasing of water by plants
into the atmosphere
The Carbon Cycle
New terms you should know…
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Decomposition—the release of CO2 from the
breakdown of dead matter
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Fossil Fuels—decaying remains of living things
containing carbon that after years of heat and
pressure that release CO2 when burned
The Nitrogen Cycle
New terms you should know…
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Nitrogen fixation—conversion of atmospheric nitrogen by
bacteria into a nitrogen containing compound that can be used
by plants and animals
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Excretion—nitrogen containing animal waste that is absorbed
by soil
Decomposition—breakdown of dead organisms which add
nitrogen to the soil
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Denitrification—conversion of nitrogen trapped in the soil and
dead animals back into atmospheric nitrogen
The Dynamics of
Communities
What is a Community?
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A collection of interacting
populations
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A groups of various species living
in the same area at the same time
Communities Need Homeostasis
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State of equilibrium
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Stable communities require:
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constant source of usable energy
organic and inorganic materials must be
recycled constantly
Symbiosis
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A close relationship between
two organisms
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Examples:
 Mutualism
 Commensalisms
 Parasitism
Mutualism
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Both organisms benefit
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Examples:
 Butterflies & flowers
food
pollination
Commensalisms
One organism benefits
 Other organism is relatively
unaffected
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Examples:
 barnacles
attached to whales
Parasitism
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One organism benefits
Other organism is harmed
Examples:
 fleas and mammals
 viruses
 pathogenic bacteria
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round worm
Predator & Prey
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One member kills and eats another
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One benefits while the other is
harmed (in the short term!!!)
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But one may adapt to the pressure
of predation
Predator & Prey Pattern
Preventing Predation
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Camouflage
Warning color
Mimicry
Succession:
natural changes in a community over
time
Examples:
increase in:
--population
--biomass
--productivity
Pioneer Species
 First
species in new
community:
Reproduce
Rapidly
Small
Survive
harsh conditions
Example: Lichen
Pioneer Forest
Changes Continue Until
Homeostasis is reached:
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Called Climax Community:
Stable
and mature
At equilibrium
Climax Community
2 Types of
Succession
Type 1:
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Primary
Creating a NEW Community
 Example
/ Causes:
Volcanic
eruptions
Clearing of Glaciers
Primary Succession
Type 2: Secondary
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Regrowth of a Previous Existing
Community
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Examples / Causes:
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Natural Disasters
 hurricanes
 forest
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fires
Human Activities
 Abandoned
farmland
 Construction / real estate
Example: Forest Fire
Yellowstone
National
Park
Secondary
Succession
1998
1988: Bunson Peak
and the area around it
was scorched by the
North Fork fire, but
has recovered nicely.
Secondary Succession
Secondary Succession
Population
Patterns
Limiting Factors in a
Community
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Any biotic or abiotic factor that limits
growth of a population
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Restrictions on populations:
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Coexistence of other populations
Size / Numbers
Reproduction
Distribution
Examples of Limiting Factors
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depletion of resources like food, water &
shelter
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appearance of predators, parasites, &
disease
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natural disasters such as fire, flood, and
drought
Carrying Capacity
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stabilizing of population growth due to
limiting factors
Density-Dependent Factor
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Limiting factors that depend on or
response to an increase or decrease in
population size
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Examples:
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Food
Water
Shelter
predators
Density-Independent Factor
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Not affected by population size
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Have the same affect on the population with
many or few members
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Examples:
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Fire
Drought
Distribution Patterns
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Patterns of organisms in a population
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Location of each organism in a populations
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Types of Distribution
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Random
Clumped
Uniform
Random
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Organisms are located in NO order / pattern
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Habitat has abundant resources throughout
Clumped
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Organisms are grouped together in various locations
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Habitat resources are located only is certain areas
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Uniformed
Organisms are found at roughly equal
distance from each other
Resources equally spread throughout the
habitat (typically man-made)
3 Age Structure Diagrams of
population patterns over time
Population
drastically
increases over
time
Examples:
Population do
NOT increase or
decreases
Examples:
Population
drastically
decreases over
time
Examples:
Organisms and
their Environment
Habitat
 the
environment in which an
organism lives or grows
Niche
The functional ROLE a species
plays in its community
 depends on:
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WHERE an organism lives
AND
WHAT it does & need for survival
Competition
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two organisms striving for the
same resource
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no one obtains 100% of the
resources, so they are all
negatively affected
2 Results of Competition
and Niche Overlap
 One
species will NOT survive
OR
 Species must change to reduce
overlap
Competitive
Exclusion Principle
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Competition for the same limiting
resource will eliminate the weaker
species
Therefore….
 No
two organisms can
have
100% identical niches
use the same resource, at the
same time, in the same place
So, fundamental
niche is reduced to
realized niche
Fundamental
vs.
Realized ???
Fundamental
Niche
 the
potential ability of a
species to receive all
possible resources
Realized Niche
 the
resources that the
species actually uses
Example: Warbler Birds
Warbler Bird Example:
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Fundamental niche –
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Realized niche –
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each warbler bird is capable of inhabiting the whole
tree
each bird limits their habitat to a portion of the tree
to:
 reduce niche overlap
 reduce competition
Fundamental niche is reduced to realized niche
to ensure coexist survival