Transcript Ecology (without Biomes)

What is
Ecology?
1
The study of
organisms
and their
environment
2
See if you know the difference between the two!
3
Abiotic or Biotic?
Biotic
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Abiotic or Biotic?
Abiotic
5
Abiotic or Biotic?
Abiotic
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Abiotic or Biotic?
Biotic
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Biotic Factors Review
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Biotic Factors
• Are the living things or their materials
that directly or indirectly affect an
organism In its environment.
• Some biotic factors include:
– Parasitism
– disease
– predation
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Biotic Factors
Producers
Organisms that make
their own food.
Ex- Plants & some
bacteria
Consumers:
Organisms that eat
(consume) other
organisms for energy
(animals)
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Biotic Factors
• Decomposers:
Consumers that eat
waste products for
energy. Waste
products are feces,
urine, fallen leaves,
dead animals.
(Fungi, some
bacteria)
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Scavengers
• Organism that
eats other dead
organisms
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Abiotic Factors
• Are those non-living physical and
chemical factors which affect the ability
of organisms to survive and reproduce
• Includes things such as:
– sunlight
– temperature
– type of soil or rock
– water availability
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Feeding Relationships
Autotrophs: Organisms that
make their own food (plants and
some bacteria)
Heterotrophs:
Organisms that eat
other organisms (they
cannot make their
own food)
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Feeding Relationships
Herbivores: eat
plants (cows)
Carnivores: eat
meat (wolves)
Omnivores: eat
plants and meat
(humans)
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Levels of
Organization
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Review: What are the Simplest
Levels?
• Atom
• Molecule
• Organelle
• Cell
• Tissue
• Organ
• Organ
System
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Which Level of Ecological
Organization?
Take this quiz to see if you can
tell the difference between the
two!
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Which Level?
• Organism – An Individual
with all characteristics of life
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Which Level of Organization?
• Population –
groups of
organisms of the same species
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Which Level of Organization?
• Biological Community – group of
populations living together
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Which Level of Organization?
Ecosystem:
the living and
nonliving parts that
are interacting
together
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Which Level of Organization?
• Biosphere:
The earth that
supports life.
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What level of organization?
Organism
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What level of Organization?
Community
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What level of Organization?
Population
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Habitat & Niche
• Habitat is where
something lives
• Niche is an
organism’s total
way of life (how it
eats, competes
with others)
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FYI- Niche
• Includes all its
interactions with the
biotic and abiotic parts
of the environment
• Each type of organism
occupies its own niche
to avoid competition
with other types of
organisms
• Two species can share
the same habitat but
not the same niche
• Example: Ants and
bacteria both live in the
dirt (habitat) but have
different niches. Ants
eat dead insects and
bacteria eat dead
leaves, dead logs, and
animal waste. So ants
and bacteria don’t
compete for resources.
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Survival Relationships
• Predator-prey: predators are
consumers that hunt and eat other
organisms called prey.
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Survival Relationships
• Symbiosis:
relationship in
which one species
lives on, in, or near
another species and
affects its survival.
• 3 Types:
– Mutualism
– Commensalisms
– Parasitism
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Mutualism
•
type of symbiosis
in which both
species benefit.
–
Ex. Clownfish
living in the sea
anemones. It
provides protection
for the fish, and
attracts potential
food for the
anemones.
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Commensalism
•
type of symbiosis
in which one
species benefits
and the other
species is neither
harmed nor
benefited
–
Example: Spanish
moss grows on the
branches of trees.
The moss gets a
habitat and the tree
gets nothing.
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Parasitism
•
one species
benefits and the
other species is
harmed.
–
–
Parasite: organism
that harms but does
not usually kill another
organism
Host: organism that is
harmed by a parasite
•
Ex. Ticks feed on dogs,
people, etc. The ticks
get food (blood) and the
hosts lose blood and
can be infected with
disease.
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Ecology- Study of interactions
between organisms and their
environment.
Producer- Uses
the sun to make
food “autotroph”
1. Organismindividual with all
characteristics of
life.
The 5 Levels
of Ecological
Organization
5. Biospherepart of the earth
that supports life
Consumerorganisms eat
others for energy
“heterotrophs”
Decomposer- break
down dead organisms
and cause decay
2. Populations- groups
of organisms of the
same species.
3. Community- group
of populations living
together.
4. Ecosystemliving & nonliving
parts interact
together.
Abiotic FactorsNon-living parts of
the environment.
Scavenger-eats
dead organisms
Biotic FactorsAll the living
parts of the
environment
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End of Day One Notes
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Trophic levels and food chains
• Trophic level: A feeding level in an
ecosystem.
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Eaten
by
1st trophic
level:
producers
(make their
own food)
Eaten
by
3rd trophic
level:
secondary
consumer
(small
carnivore)
Eaten
by
4th trophic
level: tertiary
consumer
(large
carnivore)
Bacteria
2nd trophic
level: primary
consumer
(eats plants)
Eaten
by
Last trophic
level:
decomposer
(eats dead
animals)
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Energy Pyramid
• Every time an organism eats, it obtains
energy from its food.
• So energy is transferred from the 1st trophic
level to the 2nd trophic level to the 3rd
trophic level and so on.
• Some of this energy is lost along the way
during an organism’s metabolism and as
heat.
• This energy can be measured in kilocalories
(kcal).
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Energy Pyramid
• Picture that shows how much energy is
transferred among the different trophic
levels in a food chain; energy is lost as
you move up the pyramid.
• Food chain: lineup of organisms that
shows who eats who.
– Shows how matter and energy move through
an ecosystem.
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Food Webs
• A food web is a network of connected
food chains.
More realistic than a food chain
because most organisms feed on more
than one species for food.
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Trophic Level
Energy Available
10 kcal/m2/year
4th
Tertiary
consumers
3rd
Secondary
consumers
2nd
Primary
consumers
1st
Producers
100 kcal/m2/year
1000
kcal/m2/year
10,000
kcal/m2/year
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Some energy is lost as heat and the
rest is consumed or excreted as
waste.
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Practice with Food Chains &
Food Webs
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Identify the food chains inside
the food web.
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End of Day 2 Notes
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Cycles in Nature
• There is only a limited amount of
resources (water, oxygen, nitrogen,
carbon) on the earth.
• In order to keep these resources
available to organisms, they must be
recycled after they are used.
• Cycle: a process that recycles a resource
so that you end up with what you started
with.
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Nitrogen Cycle
1. Nitrogen fixation: Bacteria
in the ground change nitrogen
from the atmosphere (N2) to
different nitrogen compounds
5. Denitrification: Bacteria
change the nitrogen
compounds back to N2 and
release it to the atmosphere
2. These bacteria live in plants
and transfer the nitrogen
compounds to the plants
4. Bacteria eat the dead
animals and animal waste and
take in the nitrogen compounds
3. Animals eat the plants and
take in the nitrogen compounds
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Nitrogen Cycle
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Water Cycle
2. Seepage: Water seeps into
the ground and plants use it
3. Transpiration: Plants give
off water to the atmosphere
1. Precipitation: Rain and snow fall from the atmosphere
to the earth
2. Runoff: Extra water runs
off the land to lower-lying
bodies of water
3. Evaporation of water
from the bodies of water
back into the atmosphere
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Water Cycle
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Carbon Cycle
1. Carbon dioxide (CO2) and
oxygen (O2) are found in
the atmosphere
2. Plants use CO2 to make
their own food
(photosynthesis)
3. During photosynthesis, plants
release O2 back into the
atomosphere
2. Animals and plants use
the O2 to make energy
(respiration)
3. During respiration, animals and
plants release CO2 back into the
atomosphere
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Carbon Cycle
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Population
Size
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Populations
• What is a population?
• What are some factors that can
contribute to the size of a population?
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Organism Interactions Limit
Population Size
Organisms depend on each other for:
Protection
Reproduction
Food
Shelter
So what happens when these
factors change?
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Organism Interactions Limit
Population Size
1. Predation:
– What could happen if a predator is
introduced to a population and there are
no organisms to eat it?
Unchecked for many
years, the snakes caused
the extinction of nearly
every native bird species
on the Pacific island of
Guam
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Organism Interactions Limit
Population Size
2. Competition
- What can happen if resources become
limited?
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Organism Interactions Limit
Population Size
3. Crowding & Stress
– As pop. Increase in size and start
straining their resources, they may
become stressed. What are some
examples of stress symptoms?
•
•
•
•
Aggression
Decrease in parental care
Decreased fertility
Decreased resistance to disease
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How do you determine
population size?
• Growth rate—amount that a
population’s size changes over
time
– Birth rate—number of births
occurring during a period of time
(ADD)
-- Death rate (or mortality rate)—
number of deaths in a period of time
(SUBTRACTS)
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How do you determine
population size?
Birth rate – death rate = growth rate
- Positive number means the pop. is
growing
- Negative number means the pop. is
shrinking
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Human population size
• Other things that affect a population’s
numbers:
• Life expectancy—how long on average
an individual is expected to live
– US men: 72 yrs, US women: 79 yrs
• Immigration—individuals moving into a
population (ADDS)
• Emigration—individuals moving out of
a population (SUBTRACTS)
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What can affect population size?
• When you figure out the number of
individuals living in a certain area, this
is called the population density.
• There are two limiting factors (biotic
and abiotic) that can affect the pop.
density
• Limiting factor—any biotic or abiotic
factor that restrains the growth of a
population
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What are limiting factors?
• Density-independent factors—factors
that affect the population regardless of
the population’s size
– Ex: fires, climate
• Density-dependent factors—factors
whose effects on the population
depend on the population’s size
– Ex. food shortages, disease
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Density- dependent or Densityindependent? Take the following
quiz to find out!
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• Predation
– Density-dependent
• Volcanic eruption
• Parasitism
– Density-dependent
• Forest fire
– Density-independent
– Density-independent
• Migration
• Chemical pesticides
– Density-dependent
– Density-independent
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Communities
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FYI: How are communities
formed?
• Communities are made of several
populations living together
• Think back to population size. What
are some limiting factors that can affect
a community?
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FYI: Forming Communities
• What would happen if people stopped cutting
the grass in their yards?
1. The grass would get taller & weeds would
grow
2. Later, bushes would grow; trees would
appear, and different animals would enter the
area
3. After 30 years, it would eventually become a
forest…BUT WHY?
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Forming Communities
Succession—orderly, natural changes
and species replacements that take
place in the communities of an
ecosystem
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Communitites
• Primary succession—
development of a community
in an area that did not
previously exist
–Ex: new volcanic island,
bare rock, sand dune
–Happens slowly
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Communities
• Pioneer species—usually
small, fast growing, and fast
reproducing organisms that
are first to colonize land after
a disturbance
• Example of primary
succession: lichens
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Communities
• Secondary succession—
sequential replacement of
species that follows a
disruption of an existing
community
• Example of secondary
succession: grasses, weeds
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Communities
• Climax community—
stable end point of a
community after
succession
takes place
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End of Day 3 Notes
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