Transcript Ecology combined 2016x

Agree/Disagree Statement Circles
• Organisms higher in a food chain eat everything that is lower in a food
chain.
• Populations higher in a food chain increase in number because they
deplete those lower in the chain.
•
The top of the food chain has the most energy because it accumulates up
the chain.
• Organisms at the top of the food chain consume organisms in the level
below them.
• Organisms are placed at the top of the food chain because they are not
hunted as prey.
• Populations at the top of the food chain are usually lower in number
because there is not enough energy to make it up the food chain.
ECOLOGY – What is it?

The scientific study of interactions between
organisms and their environments, focusing on
energy transfer

It is a science of relationships.
The environment is made up of two factors:

Biotic factors- all living
organisms inhabiting the
Earth

Abiotic factorsnonliving parts of the
environment (i.e.
temperature, soil, light,
moisture, air currents)
Levels of Organization in Ecology

Organism →Species  Population → Community →
Ecosystem → Biome → Biosphere
Levels of Organization

Species - Group of organisms so similar to one another
that they can breed and produce fertile offspring.


Population - Groups of individuals that belong to the
same species and live in the same area.


Ex - elephant
Ex – herd of elephants
Communities - Assemblages of different populations that
live together in a defined area.

Ex – elephants, zebras, water buffalos, warthogs, hippos
Levels of Organization

Ecosystem – Collection of all living and nonliving things in
a determined place


Biome - Group of ecosystems that have the same climate
and similar dominant communities.


Ex – mud hole, grass, warm temperature, elephants, zebras,
giraffes, insects, sun
Ex – Tropical Savanna (Kenya, Zaire, Tanzania-Africa)
Biosphere – Part of the planet in which all life exists,
including land, water, and air (all ecosystems combined)

It extends from about 8 kilometers above Earth's surface to as
far as 11 kilometers below the surface of the ocean.
Habitat vs. Niche…
 Niche
- the role a species plays in a
community (job)
 Habitat-
the place in which an organism
lives out its life (address)

A niche is determined by the tolerance limitations
of an organism, or a limiting factor.
What is the niche of these animals?
Consumers
1.
2.
3.
4.
5.
Herbivores - eat plants
Carnivores – eat animals
Omnivores – eat both plants and animals
Decomposer – break down dead
organic matter chemically (bacteria)
Detritivores – feeds on plant and
animal remains (crab, earthworm)
Decomposers vs. Detritivores

Decomposers
1.

Bacteria and fungus
Detritivores:
1.
2.
3.
4.
maggots
dung beetles
earth worms
sow bugs
Without them there
would be a lot of dead
bodies lying around!
Leeches and
maggots are now
classified as FDAapproved medical
devices — the first
live animals to earn
that distinction.
Interesting Science!
These maggots are cleaning/removing
the dead tissue from this wound. If the dead tissue is not removed, the
wound will not heal correctly…may end up with a big hole in their heel.
Interesting Science!
All of the yellow tissue is necrotic
(dead) tissue. The pink tissue is granulation (newly formed) tissue. The
dead tissue must be removed for proper wound care or else the tissue
will not grow and fill in the hole
Food Chain vs. Food Web
1.
Food Chains shows how matter and
energy move through an ecosystem
1.
follow just one path as animals find food.
2. Food Webs
shows all
possible feeding
relationships in a
community at
each trophic level
I. follow all possible energy paths
What Do Food Chains and Food
Webs Demonstrate?

Both food chains and food webs show the flow of
energy in an ecosystem.
Energy flows from
the leaf to the
mouse
Energy flows
from the snake
to the hawk
Trophic Levels


Corresponds to the different
levels or steps in the food chain.
Represent a feeding position in
the transfer of energy and matter
in an ecosystem.



Green plants: first trophic level, the
producers.
Herbivores: second trophic level
Carnivores: third and even the
fourth trophic levels.
Food Chains
ALWAYS begin with
plants (producers)!!
Trophic Levels
Tertiary consumerstop carnivores
Secondary consumerssmall carnivores
Primary consumers- Herbivores
Producers- Autotrophs
Matter vs. Energy


Matter – Has mass, takes up space, is usually a “thing”
Energy – Not like matter, does not have mass, does not
take up space,
energy moves
matter

Forms of energy:
light, heat, sound,
motion, and
electricity
How Much Energy is Passed On?


Only 10% is passed on to the next trophic level
The other 90% is lost/given off as heat
100%
10%
1%
.1%
Food Chains: Matter and Energy


As you move up a food
chain, the matter and energy .1% Energy
decreases.
1% Energy
Energy is transferred
upwards but is diminished
10% Energy
with each transfer.
100% Energy
Pyramids are larger at the bottom…more matter
and energy are at the bottom of the pyramid!
Ecological Pyramids

Ecological Pyramiddiagram that shows the
relative amounts of energy
or matter contained within
each trophic level in a food
chain or food web.
Two Types of Ecological Pyramids
1.
2.
Pyramid of Biomass – Represents the biomass at each
trophic level
Pyramid of Numbers – Represents the number of
organisms at each trophic level
Ecological Pyramid: Pyramid of Biomass

Biomass – total amount of
living tissue within a
trophic level

Usually expressed in grams
per unit area.

As you move up a food
chain, both available
energy and biomass
(matter) decrease.

Energy is transferred
upwards but is diminished
with each transfer.
Pyramid of Numbers
As you go further
down a food chain,
the numbers of
organisms decrease
because there is less
energy available (like
in this meadow)!
Other Pyramid of Numbers
If you have a large
producer (such as a
tree in a forest), the
pyramid of numbers
may look diamond in
shape.
A large tree
supports a lot of
organisms.
Population Changes in Food Chains

What would happen to this bird if the population of
caterpillars decreases?
Population Changes in Food Chains

What would happen to this bird if the population of
caterpillars decreases?

The bird population would decrease also because he
would have less food.
Population Changes in Food Chains

What would happen to the bee population if the flower
population exploded?
Population Changes in Food Chains

What would happen to the bee population if the flower
population exploded?

The bee population would also increase.
Population Changes in Food Chains

If the snake population
decreases, what would happen
to the other organisms in the
food chain?
Population Changes in Food Chains
• If the snake population
decreases:
– The hawk population
decreases also (less food)
– The frog population
increases (less predators
eating them)
– More frogs eating the
grasshoppers, so less
grasshoppers
Carrying Capacity and Predators
Carrying Capacity

Number of species that can be supported by an
ecosystem. (Average growth rate = zero)
Population Growth is Represented With an S-Curve
Population Growth

Exponential - individuals in a
population reproduce at a
constant rate (Ideally happens IF
there are unlimited resources)
(J-curve)

Logistic – The growth of a
population slows or stops as
resources become less available
(S-curve)
.
3 Factors that affect population size:

1. # of births





Populations will grow if birthrate > death rate
Populations will shrink if birthrate < death rate
Populations will stay the same birthrate = death rate
2. # of deaths
3. # of individuals that enter or leave a population


Immigration = movement of individuals INTO an area (growth)
Emigration = movement of individuals OUT of an area (shrink)
 Limiting
factor- any biotic or abiotic
factor that restricts the existence of
organisms in a specific environment.
Limiting Factors: Limit Population
Growth
Limiting factors:
a. Density independent: factors that affect all members
of the population equally if population is dense or not.
 Natural disasters: floods, earthquakes, wildfires,
tornadoes, mudslides, pollution, habitat
destruction
b. Density dependent: factors that affect crowded
populations
 EX: competition, predation, crowding and stress,
parasitism, and disease
Competition

Competition – A rivalry between organisms for the same
resources; The fitness of one of the organisms is lowered by
the presence of another.

Limited supply of at least one resource used by both organisms is
required

Example:Animals compete for
food, mating, or territory and
plants can compete for water,
food, minerals, sunlight.
Predators

Organism that hunts and kills other organisms

Can be carnivores or omnivores
The Importance of Predators
We need them to control populations



Without predators, certain species like mice would crowd
out other species and would also destroy their habitat.
They also get rid of weak, crippled, stupid, stunted, and
diseased organisms (survival of the fittest)
Predator Prey Graph
Large Predators

The number of large
predators is decreasing.
Wild Rabbits in Australia

Early 1900's, wild rabbits were taken from England to
Australia to be used for hunting.


Since then, rabbits have multiplied exponentially and have
severely affected the ecosystem where they live.
Damages include:
1.
2.
3.
Loss of vegetation from rabbit
grazing – threatens the
survival of native animals that
rely on plants for food and
shelter
Wild rabbits compete with
livestock for available pasture
and kill young trees & shrubs.
The holes they dig contribute
to soil erosion by removing
vegetation and disturbing soil.
Symbiotic Relationships:

Interactions between two or more organisms; Two
different species start a relationship (interact) in order to
ensure survival
Predation

The capturing of prey as a means of maintaining life


One organism benefits
One organism is killed
Parasitism
One organism (the
parasite) benefits
and the other (the
host) is harmed, but is
still alive
Because the
parasite needs
the host to
remain alive, it
is typically
advantageous
for the parasite
NOT to kill its
host
A tomato hornworm is
covered with cocoons of
pupating braconid wasps
Mutualism

Relationship that benefits both species.
Examples of Mutualism



Pollination
Seed Dispersal
Anemones
http://player.discoveryeducation.com/index.cfm?
guidAssetId=5A1EACD2-3483-41F0-86B147B8300065E0&blnFromSearch=1&productcode
=US
Hippo and fish
Commensalism

One species benefits and the second species is
unaffected
Barnacles and Cattle Egrets

Barnacles and Algae
Interactions Summary
Type of
Interaction
Predation
Parasitism
Mutualism
Commensalism
Organism 1
Organism 2
Is Killed
Still Alive
“It’s Mutual.”
Changes in Ecosystems:
Ecological Succession
Ecological Succession
• Ecosystems are constantly changing in
response to natural and human disturbances.
• As an ecosystem changes, older inhabitants
gradually die out and new organisms move in,
causing further changes in the community.
– Ecological Succession – Series of predictable
changes that occurs in a community over time
Some Causes of Ecological
Succession
• Can result from slow changes in the physical
environment or from sudden disturbances
(either natural or man made).
– Some causes include:
1. Clearing land
2. Climate change
3. Introduction of nonnative
species
4. Natural disasters such as
volcanic eruptions, forest
fires, hurricanes, & floods
Succession:
• Natural, gradual changes in the types of
species that live in an area; can be
primary or secondary
• The gradual replacement of one plant
community by another through natural
processes over time
Primary Succession
• Begins in a place without any soil
– Sides of volcanoes
– Landslides
– Flooding
• Starts with the arrival of living things such
as lichens that do not need soil to survive
• Called PIONEER SPECIES
http://botit.botany.wisc.edu
http://www.saguaro-juniper.com/
Primary Succession
• Soil starts to form as lichens and the
forces of weather and erosion help break
down rocks into smaller pieces
• When lichens die, they decompose,
adding small amounts of organic matter to
the rock to make soil
http://www.life.uiuc.edu
Primary Succession
• Simple plants like mosses and ferns can
grow in the new soil
http://www.uncw.edu
http://uisstc.georgetow
n.edu
Primary Succession
• The simple plants die, adding more
organic material
• The soil layer thickens, and grasses,
wildflowers, and other plants begin to take
over
http://www.cwrl.utexas.edu
Primary Succession
• These plants die, and they add more
nutrients to the soil
• Shrubs and tress can survive now
http://www.rowan.edu
Primary Succession
• Insects, small birds, and mammals have
begun to move in
• What was once bare rock now supports a
variety of life
http://p2-raw.greenpeace.org
Mount St. Helen Before Eruption in 1980
Mount St. Helen 6 Years After Eruption
Mount St. Helen After Eruption
Mount St. Helen 10 Years After Eruption
Mount St. Helen 19 Years After Eruption
Secondary Succession
• Begins in a place that already has soil and
was once the home of living organisms
• A disturbance of some kind changes an
existing community
• Occurs faster and has different pioneer
species than primary succession
• Example: after forest fires
http://www.geo.arizona.edu
http://www.ux1.eiu.edu
Climax Community
• A stable group of plants and animals that
is the end result of the succession process
• Does not always mean big trees
– Grasses in prairies
– Cacti in deserts
The Carbon Cycle
Why is Carbon important?
All living things are made of carbon!!!
• Calcium carbonate (CaCO3) makes up
animal skeletons
• Carbon Dioxide gas which makes
photosynthesis and respiration work
together
Carbon Does Not Stay Still – It Is
On the Move!
1. In the atmosphere, carbon is attached to some oxygen in
2.
3.
4.
5.
a gas called carbon dioxide.
Plants use carbon dioxide and sunlight to make their own
food and grow. The carbon becomes part of the plant.
Animals consume plants. The carbon becomes part of the
animal.
Plants that die and are buried may turn into fossil fuels
made of carbon like coal and oil over millions of years.
When humans burn fossil fuels, most of the carbon
quickly enters the atmosphere as carbon dioxide.
PHOTOSYNTHESIS
Using light energy, plants combine
carbon dioxide (CO2) from the
atmosphere and water (H20) to form
sugar and oxygen in the process of
photosynthesis.
sunlight
(CO2) + (H2O) →
(C6H12O6 ) + (O2)
What is Sugar (Glucose)
Used For?
1. Source of energy
2. Building block for
other compounds such
as proteins, oils, and
starches.
RESPIRATION
• In respiration, the compounds
containing carbon (the organic
compounds) are broken down, and carbon
dioxide is released.
Plants, animals, and
microorganisms all
carry out respiration!
IS THE CARBON-OXYGEN CYCLE
BALANCED?
• The Carbon-Oxygen cycle is out of
balance.
• There is more carbon dioxide being
released into the atmosphere than is being
removed.
COMBUSTION
• Most of the carbon dioxide is
produced during the process
of burning called
combustion.
• When compounds containing
carbon (wood, coal, or oil) are
burned, the carbon is
chemically combined with
oxygen, and carbon dioxide is
released.
• The use of carbon dioxide by plants during
photosynthesis is a much slower process.
• As a result of the imbalance between
these two processes, the level of carbon
dioxide in the atmosphere is increasing.
• “Even if human emissions of CO2 magically dropped to
zero, the gas already in the air would linger for many
centuries, trapping heat. Global temperatures would
continue to creep upward until the ocean depths
reached equilibrium with the heated air, until biological
systems finished adapting to the new conditions, and
until Arctic icecaps melted back to their own equilibrium”
Decomposers
• When organisms die,
decomposers break down the
carbon compounds in their
bodies, and carbon dioxide is
returned to the atmosphere.
• During decomposition
(decay), other chemicals are
also returned to the soil or
released into the air. One of
these chemicals is nitrogen.
The Nitrogen Cycle
NITROGEN
• Plants and animals need
nitrogen to make amino
acids (proteins)
• The atmosphere is about
78% nitrogen gas, but
plants and animals cannot
use nitrogen directly from
the air.
How Do Plants Get Nitrogen?
• Special bacteria, in the soil
and water, must change or
“fix” nitrogen gas (N2) into
nitrogen fertilizers (NO3-) or
ammonium ions (NH4+) that
plants can use.
• These bacteria are called
nitrogen-fixers.
N=N → 2NH3
Nitrogen Fixers
Most nitrogen-fixing bacteria live
in little houses, or nodules, on
the roots of plants called
legumes.
• Legumes - members of a large family of
plants that include peas, beans, alfafa,
and clover.
• Convert nitrogen gas to ammonia
Nitrogen Fixers
• Mutualistic Relationship
– The plants provide food and cover for the
bacteria, and the bacteria convert nitrogen
gas into fertilizer for the plant.
How Do Animals Get Nitrogen?
• Animals get nitrogen from plants or from other
plant-eating animals, in the form of protein.
Animals must
eat protein to
get our nitrogen
requirements!
We can’t breathe
in nitrogen.
How is Nitrogen Recycled?
Nitrogen is recycled by special bacteria (legumes) that
break down the nitrogen compounds (proteins) in dead
plants and animals, and in animal wastes.
If plants do not use the nitrogen compounds as
fertilizer, special forms of bacteria may recycle it.
These bacteria convert the unused fertilizer into
nitrogen gas and release it into the atmosphere.
All natural ecosystems
depend upon
bacteria to keep the
nitrogen cycle going!
Lightning and the Nitrogen Cycle
• Lightning plays a small
role in the nitrogen cycle.
• The high temperature and
pressure from lightning
combines nitrogen and
oxygen (nitrogen oxides)
in the atmosphere.
– The “fixed” nitrogen,
(which is dissolved in the
rain making nitrates)
enters the soil
Combustion: Another source of
Nitrogen
• The burning of fossil
fuels is another
source of nitrogen.
– Combustion causes
nitrogen and oxygen
to combine creating
nitrogen oxides (NOx).
These lead to acid rain
and smog