Transcript Introduction to Ecology

Introduction to
Ecology
Ecology
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The study of interactions among organisms
and between organisms and their environment,
or surroundings.
Discovery Channel :: Planet Earth :: Portrait of
the Planet
Ecosystem
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Living and non-living
factors in the same place
at the same time
Ex:
fish tank, pond, forest,
etc.
Organization of the Ecosystem
Go to
Section:
Biotic Factors
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Living factors that has an effect on another
living organism
Example for a bird:
Trees, other birds, insects, worms, etc
Abiotic Factors
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Non-living factors
that has an effect
on a living
organism
Example for a
bird:
Water, wind,
temperature, light
Abiotic and Biotic Factors
Abiotic Factors
Biotic Factors
ECOSYSTEM
Discuss 2 ways biotic factors and 2
ways abiotic factors can affect the life
of a tree.
Habitat
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The place where an organism lives
The address
The habitat for a bull frog =
The habitat of the giant anteater =
Niche
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What an organism does in an environment
The occupation or the role of an organism
Includes how an organism gets its food,
reproduces, avoids predators, etc.
Determines an organisms habitat
Example:
Wood peckers survive by finding insects in the
bark of a tree
Three Species of Warblers
and Their Niches
Cape May Warbler
Feeds at the tips of branches
near the top of the tree
Bay-Breasted Warbler
Feeds in the middle
part of the tree
Spruce tree
Yellow-Rumped Warbler
Feeds in the lower part of the tree and
at the bases of the middle branches
Limiting Factors
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Each species is adapted to a specific set of
conditions
Organisms thrive best in environments that
have specific conditions that meet their needs.
Example:
Plants need sunlight.
Certain fish may prefer certain water
temperatures therefore will be found at certain
depths.
Populations
&
Communities
Population
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All the organisms of one species that live in
one place at a particular time
Example:
Herd of deer
Flock of geese
Community
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All of the populations that interact with each
other in a particular place
Living Organisms
Example:
Bison, antelope, insects, grass
Wolf and Moose
Populations on
Isle Royale
60
2400
1990
Moose
1995
Wolves
0
0
1955
1960
1965
1970
1975
Moose
Go to
Section:
1980 1985
Wolf
1990
1995
Community Interactions
Competition
 Predation
 Symbiosis
 Succession
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Competition
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The main interaction between organisms
May be for food, water, shelter, mate
Results in natural selection= best fit survive
(evolution)
• Types of Competition:
1. interspecific: competition between two different
species
Ex: lions and hyenas
2. intraspecific: competition between members of the
same species
Ex: a female lion competes with other lions for
food
Can you identify the types of
competition???
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Video - on CBS
 Number 2
 Number 3
Predation
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As a member of a population, you either “eat
or be eaten”
Members of one population are the food
source for another population
Predator:
The organism which is eating another
Prey:
The organism which is being eaten
Define interspecific and
intraspecific forms of competition.
Give an example of each type.
Symbiosis
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When an organism has a close relationship
with another organism
Each partner can help the other, harm the
other, or have no effect on the other partner
Video clip of Symbiosis
Types of symbiosis
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1. parasitism:
A parasite lives on or in another organism for food or shelter
The host usually continues to live, but it is harmed
Ex: tapeworm in the human intestines
2. commensalism:
One organism benefits while the other is unaffected
Ex. birds on the back of a buffalo
Fish attached to shark
3. mutualism:
Both members of the relationship benefit
Ex: bacteria in our intestines
Bees and flowers
Succession
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The gradual replacement of one type of community
for another
Occurs 2 ways:
1. Primary succession:
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Occurs in areas where there is no soil (bare rock,
hardened lava or ash)
Lichens: first organism to appear; also called pioneer
species
2. Secondary succession:
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Occurs in areas where soils present (after a forest fire)
Lichens
Ecosystems
Basic Characteristics
of an Ecosystem:
1.
2.
3.
Biotic Factors
Abiotic Factors
Energy Flow between organisms and their
environment
Freshwater Pond Ecosystem
Spoonbill
Frogs lay eggs in the shallow
water near shore.The eggs
hatch in the water as tadpoles
and move to the land as adults.
The shore is lined with grasses
that provide shelter and nesting
places for birds and other
organisms.
Duck
Water
Frog lilies Mosquito
Duckweed
larvae
Dragonfly
Snail
The roots of water lilies
cling to the pond bottom,
Pickerel
Diving
beetle Fish share the pond
while their leaves, on long
flexible stems, float on the
with turtles and other
surface.
animals. Many of
them feed on insects
at the water’s edge.
Trout
The bottom of the pond is
inhabited by decomposers and
Hydra
other organisms that feed on
particles drifting down from the
Snail Crayfish
surface.
Phytoplankton
Plankton and the organisms that
feed on them live near the surface
where there is enough sunlight for
photosynthesis. Microscopic algae
are among the most important
producers.
Benthic
crustaceans
Energy Flow through Ecosystems
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Sunlight: main source of energy for life on
Earth
Trophic levels:
Trophic= feeding
examples:
producers
consumers
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1st level
Also called autotrophs
Uses energy from the environment
(SUNLIGHT)
plants
Primary Consumers
• Also called heterotrophs
• Organisms that feed on producers
• Deer, buffalo, mice, etc
Secondary Consumers
• Organisms that feed on primary
consumers
• Birds, fox, etc
Tertiary Consumers
• Organisms that feed on secondary
consumers
• Large hawk, cat, etc
Types of Consumers
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Herbivores:
Eats plants Ex. cows, deer, caterpillars
Carnivores:
Meat eaters Ex: snakes, dogs, owls
Omnivores:
Eats both plants and animals Ex. humans
Detritivores:
Feeds on plant and animal remains and other dead matter
Ex. mites, earthworms, snails, crabs
Decomposers:
Breaks down organic matter
Ex. bacteria, fungi
Food Chain
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Energy that is passed from one trophic level to
a trophic level that is higher
Example:
Food Web
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Interconnected Food
Chains
Food Pyramid
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Shows trophic levels
Producers on lowest level
Also can show total mass of each organism in
the level
Ecological
Pyramids
Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent of this
energy for
life processes.
The rest is lost
as heat.
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.
Pyramid of Numbers
Shows the relative
number of individual
organisms at each
trophic level.
DDT and Food Webs
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DDT was used as insecticide
DDT does not break down in organisms and is
passed from one trophic level to the next
Highest levels found at the top of the food
chain
Known as biomagnifications
DDT in Eagles and Osprey
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Have highest levels of DDT
Causes shells of eggs to be fragile
Cause decrease of populations
 Why is a food web more
accurate than a food chain in
portraying the relationships
that exist among organisms in
an ecosystem?
Biome
•Based on yearly precipitation and temperature
(climate)
Heating of the Earth’s Surface and Some
Factors That Affect Climate
Different Latitudes
Greenhouse Effect
Sunlight
Sunlight
90°N North Pole
66.5°N
Arctic circle
Some heat
escapes
into space
Greenhouse
gases trap
some heat
Sunlight
Tropic of Cancer
23.5°N
Equator
Most direct sunlight
Tropic of Capricorn
66.5°S
23.5°S
Sunlight
Atmosphere
Arctic circle
Earth’s surface
0°
Sunlight
90°S South Pole
The World’s Major
Land Biomes
Tropical rain forest
Temperate grassland
Temperate forest
Tundra
Tropical dry forest
Desert
Mountains and
ice caps
Tropical savanna
Temperate woodland
and shrubland
Northwestern
coniferous forest
Boreal forest
(Taiga)
Biome
Tropical Rain
Forest
Tropical Dry
Forest
Tropical
Savanna
Desert
Temperate
Grassland
Temperate
woodland and
Shrubland
Temperate
Forest
Precipitatio Temperature Soil
n
high
hot
poor
Diversity
Trees
Grasses
high
dense
sparse
variable
mild
rich
moderate medium
medium
variable
mild
clay
moderate sparse
dense
low
moderate
variable
summer hot
poor
rich
moderate sparse
moderate absent
sparse
dense
summer
low, winter
moderate
moderate
summer hot
poor
low
medium
medium
summer
rich
moderate,
winter cold
summer mild, rocky,
winter cold
acidic
high
dense
sparse
low
dense
sparse
summer mild, poor,
winter cool
acidic
summer mild, poor
winter cold
moderate dense
sparse
low
medium
Northwestern
Coniferous
Forest
Boreal Forest
high
Tundra
low
moderate
absent
Project
• Food Web Biome Poster
The Recycling of Materials in
Ecosystems:
Carbon
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4 ways carbon is recycled in an ecosystem:
1. photosynthesis
2. respiration
3. decomposition (decay)
4. burning
The Carbon Cycle
CO2 in
Atmosphere
CO2 in Ocean
Oxygen Cycle
Nitrogen
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Nitrogen fixation:
Special type of bacteria found on the roots of
legumes (peas, beans, peanuts, alfalfa, clover)
Take free nitrogen from air and change it into
nitrates
Nitrates used to make plant grow, plant
produces nutrients for bacteria = mutualism
The Nitrogen Cycle
N2 in Atmosphere
NH3
NO3and NO2-
The Water Cycle
Condensation
Precipitation
Evaporation
Transpiration
Runoff
Seepage
Root
Uptake
Importance of
Biodiversity
Hardy-Weinberg Law
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5 conditions that must occur for a population not to
change:
1. no mutations
2. no immigration (entering) and no emigration
(leaving)
3. population must be large
4. individuals have the same chance of surviving
5. matings of individual organisms must be
random
Biodiversity
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The amount of variety in a community
Also called species diversity
• Low biodiversity:
Few species of plants and animals
• High biodiversity:
Many species in a community
Importance of Biodiversity
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1. ecosystem stability
2. medicinal purposes, possible cures for
diseases
Main reason why biodiversity is decreasing:
Habitat destruction
Ways humans destroy habitats:
Clearing land
building dams
highways, etc
Rain Forests
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70 -90% of the earth’s biodiversity will be lost
with destruction of rain forests
Scientists are trying to identify and classify
many newly discovered organisms
Fear that we are losing valuable medicines
People and the
Environment
Desertification
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Severe threat to our soil supply
Loss due to drought or poor farming practices
Ex.
Cattle grazing: Eat plants down to the roots;
plants can no longer hold nutrients. Land
becomes dry and bare.
Irrigation: water pumped from the ground
contains minerals (salt). Water evaporates,
minerals remain. Land is unsuitable for
agriculture.
Erosion
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Increased as humans cut forests and removes
plants
Loose soil is washed away by rain
Example:
Dust Bowl: Great Plains 1930’s
Farmers now grow crops in ways that
reduce soil erosion
Water pollution
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Raw sewage
Thermal pollution
Air pollution
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Addition of gases and tiny solid particles
added to the air by human activities
Harmful Human Activities
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Burning of fossil fuels (coal, oil, natural gas)
Industry
Forest fires
Natural Occurrences
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Forest fires
Dust storms
Erupting volcanoes
Global
Air Pollution
Problems
Acid Rain
(Acid Precipitation)
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Harmful gases produced by burning coal, oil,
and gasoline
Gases carried by winds for long distances
Gases combine with water droplets, making
the rain acidic
Damage has been done to many forests, lakes,
rivers, etc.
Also damage to statues.
Global Warming
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Earth kept warm by carbon dioxide in the atmosphere
(greenhouse effect)
Burning of fossil fuels releases excessive amounts of
carbon dioxide, which causes more heat to be
trapped.
Also caused by burning of rain forests as land is
cleared.
Average global temperatures have increased in the
past 100 years
Causes climate changes which result in movements in
plant and animal species
The Greenhouse
Effect
Sunlight
Some heat
escapes
into space
Greenhouse
gases trap
some heat
Atmosphere
Earth’s surface
Ozone Depletion
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Caused by Chlorofluorocarbons
(CFCs)
Found in air conditioners,
refrigerators, aerosol cans (hair
spray, deodorant, spray paint, etc)
Ozone blocks UV radiation from
the sun.
UV rays damages DNA in our
cells (skin cancer)
Montreal Protocol: 1987
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Agreement between many countries listing
steps needed to protect the ozone layer by
limiting or eliminating the use of ozonedepleting chemicals by 1996.
Human Population Growth
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Most serious problem that affects all life on
Earth
Increasing Agricultural revolution (better tools
and methods) and Industrial Revolution
Advances in farming and medicine.
1960 3 billion vs. 2000 6 billion (?)
What is Earth’s carrying capacity for the
human population?
Human Population
Growth
Industrial
Revolution
begins
Agriculture
begins
Bubonic
plague
Plowing
and
irrigation
International Conference on
Population and Development: 1994
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160 countries met
Agreed that population growth can not
continue at current rate
Population of any organism can not increase
forever.
Polluted land, water, and air; lack of food and
space; and widespread disease will limit
population size
Direct Harvesting
• Destruction or removal of species from
their habitats
• Can lead to the extinction of species
• Ex:
Monkeys and parrots from the rain
forest
Baby harbor seals (for pelts)
Elephants (tusks to make jewelry)
Saving the
Biosphere
Dr. Seuss, The Lorax
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As an individual, make
a list of things that you
can do to protect our
environment.
Reduce: (use less)
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Use a mug or glass instead of paper cups for
drinks
Make double sided photocopies
Bring your own shopping bags to grocery store
Reuse
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Paper or plastic grocery bags
Water jugs
Recycle
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Plastic
Glass
Metal
Paper
Examples:
1. Black Asphalt in NYC contains recycled glass
2. Building materials are made to look like wood
(actually plastic)
Renewable vs.
Nonrenewable
Renewable
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Can be replaced within a generation
Enough is being made to replace what is being
used
Ex:
Food
Wood
Oxygen
Nonrenewable:
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Can not be replaced
Ex:
Coal, oil, natural gas
Gold, silver, iron, copper, aluminum
Sand, gravel, limestone
Things humans can do to
improve the biosphere
• Windmills, Endangered Species Act, The
Environmental Protection Agency, etc
HELP!
We are being invaded by aliens!
Foreign Species
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Plants or animals that are not native to an area
Multiply very quickly because they do not
have any predators or competitors
Often cause native species to decrease in
number
Zebra Mussels
(Russian native)
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When? 1980’s
Where? St.Lawrence River
Why? By accident, carried on boat
What is the problem?
Attach themselves to surfaces and colonize
Clog piped, motors, bridges
Found in many waters of the eastern United
States
Mongoose
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When? 1877
Where? Puerto Rico
Why? Used to control rats that were damaging
sugarcane crops
What is the problem?
Rats learned to avoid the mongoose. Mongoose
began to eat poultry, birds, and lizards. As lizard
population decreased, June beetle populations
increased. The also are pests of the sugarcane.
Purple Loosestrife
(European native)
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When? Early 1800’s
Where? All of United States
Why? Ornamental plant
What is the problem?
It has invaded the wetlands of all 48 states.
It has crowded out 44 native plants and endangered
the wildlife that depends on these plants.
Approximately $45 million is spent a year trying to
control it.
The English Sparrow
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When? 1853
Where? United States
Why? Control canker worms (garden pests)
What is the problem?
Ate crops instead.
Displaces native birds and harasses others.
Carries 29 diseases that affect both humans and
domestic animals.
Canker worms are still garden pests!