Transcript Ecology - cloudfront.net

Ecology
Ecology: the study of how living things
interact with their physical environment
To be used with Ecology Guided Notes
Gaccione/Bakka—Belleville High School
Ecological Organization
Organism
• A living thing
• Anything that possesses all of the
characteristics of life
Ecological Organization
• Species: a group of organisms that can
mate & produce a fertile offspring
Ecological Organization
• Population: all the members a species
that live in certain place at a certain time.
Ecological Organization
• Community: a collection of interacting
populations in an area
Ecological Organization
• Ecosystem: includes all of the organisms
& the non-living environment.
– community members
in the ecosystem
must interact to
maintain a balance.
Ecological Organization
• Biosphere: the portion of the earth where all life exists.
A 13 mile band that surrounds the earth.
6-7 miles into the atmosphere & 6-7 miles deep into the
ocean.
– Composed of many complex ecosystems.
Put in order:(small to large)
community
Population
species
biosphere
organism
ecosystem
Ecosystems
An ecosystem is self-sustaining if:
1. A constant source of energy
is supplied.
2. Living things use this energy and
convert into organic molecules
3. A cycling of materials between
organisms and their environment
Resources
• Organisms with similar needs may compete
with each other for resources like:
1. Food
2. Space
3. Water
4. Air
5. Shelter
Limiting Factors
• Limiting Factor:
anything that makes it more difficult for a
species to live, grow, or reproduce in its
environment
– Determines the types of organisms that exist
in that environment
Acclimation
when organisms acclimate to changes
• Range of Tolerance: the ability of an
organism to withstand changes in their
environment.
Abiotic Factors
• Abiotic factors: nonliving factors which affect
the ability of organisms to survive and reproduce
Examples:
1. intensity of light
2. range of temperatures
3. amount of moisture
4. soil or rock type
5. availability of inorganic substances
6. supply of gases such as oxygen, carbon
dioxide, and nitrogen
7. pH
Examples of Abiotic Factors
What abiotic factors limit
vegetation at higher altitudes?
1.
2.
3.
4.
lack of soil
a low annual temperature
strong winds
steepness of the grade
Examples of Abiotic Factors
What abiotic factors allow rainbow trout to love
mountain streams?






the amount of dissolved oxygen due to current
water temperature
no pollution
pH of 7
shelter
river bottom for reproduction
Examples of Abiotic Factors
What abiotic factors limit the organisms that can
live there?





temperature
sunlight
lack of water
winds
shelter/shade
Biotic Factors
• Biotic factors: living factors which affect the
ability of organisms to survive and reproduce
– Examples:
• other organisms, such as a predator, food source
Can an abiotic factor such as RAIN affect many biotic
factors?
grass - ________
mole
eagle
Rain - ________
- _________
Nutritional Relationships
• Two types : Autotrophs & Heterotrophs
– Autotrophs: organisms that synthesize their
own food from inorganic molecules
Plants that contain
photosynthetic pigments,
such as chlorophyll.
Nutritional Relationships
• Two types : Autotrophs & Heterotroph
– Heterotrophs: can NOT synthesize their own
food and are dependent on other organisms
for their food
Types of Heterotrophs
• Saprophytes: include those heterotrophic
plants, fungi, and bacteria which live on
dead matter (a.k.a. decomposers or
detritivores)
Types of Heterotrophs
• Herbivores: plant-eating animals
Types of
Heterotrophs
Omnivores:
• consume both
plants and meat
Types of Heterotrophs
• Carnivores: meat-eating animals
Types of Carnivores
 Predators: animals which kill and
consume their other animals (prey)
 Prey: animals which are killed by predators
More Predator/Prey Relationships
Types of Carnivores
 Scavengers: those animals that feed on other
animals that they have not killed
Examples: crows
vultures
hyenas
Which is the Predator?
Symbiotic Relationships
• Symbiosis: living together with
another organism in close association
–Types of symbiosis:
• Commensalism
• Mutualism
• Parasitism
Types of Symbiosis
• Commensalism: one organism is
benefited and the other is unharmed (+,0)
– Example: barnacles on whales, orchids on
tropical trees
Types of Symbiosis
• Mutualism: both organisms benefit from
the association (+,+)
– Example: Nile crocodile opening its mouth to
permit the Egyptian plover to feed on
any leeches attached to its gums.
Types of Symbiosis
• Parasitism: one organism benefits at the
expense of the host (+,-)
– Example: tapeworm and heartworm in dogs
athlete's foot fungus on humans
leech sucking blood from host
Symbiosis
Mutualism
Parasitism
Commensalism
Energy Flow in an Ecosystem
• Food chain: a single pathway of feeding
relationships among organisms that
involves the transfer of energy.
Food Webs
• Food web: Interrelated food chains in a
community
– Most organisms may be
consumed by more
than one species
Trophic Levels
An organism’s
position in a
sequence of
energy transfers
Fourth
trophic
Third
trophic
Second
trophic
First trophic
level
Energy Transfer
• There is a decrease in the overall energy as you
move up in trophic levels.
• There is much more energy in the producer level in
a food web than at the consumer levels
• Approximately 10% of ingested nutrients is passed
on to the next trophic level to build new tissue
Energy Flow, continued
Why is the % of energy passed on to the next
trophic level so low?
• No transfer of energy 100%, therefore some
energy is lost in the form of heat
• Some animals escape from being eaten & just
die. Their energy in their bodies do not pass to
a higher energy level.
• Some animal parts can not be eaten.
Cougar eats deer, can not extract energy from
antlers, hooves or hair.
Biomass: amount of organic matter
producers
primary consumers
secondary consumers
tertiary consumers
Terrestrial Energy Pyramid
Eagles
Snakes
Mice
Green Plants
Complete the Energy Pyramid using these organisms:
Eagles, Green Plants, Mice, and Snakes
Succession
• Succession: a gradual process of change and
replacement of populations in a community.
– Succession occurs when the environment is altered.
– These changes cause species to replace others,
resulting in long-term gradual changes in
ecosystems
– Ecosystems tend to change until a climax
community is formed.
Primary Succession
• The development of plant communities in
an area that has never supported life.
• examples: bare rock, lava flow or glaciers.
Primary Succession - in a Pond
The Start of Primary Succession
• Pioneer organisms: the first organisms to
inhabit a given location
(example: lichens on bare rock)
– Breaks down rock into soil
– Establish conditions under
which more advanced
organisms can live.
Primary Succession Example
Adirondack Bog Succession
1. water plants at pond edge
2. sedges and sediments begin to fill pond
3. sphagnum moss and bog shrubs fill
pond (cranberries)
4. black spruce and larch
5. birches, maple, or fir
Secondary Succession
• is the change of species that follows disruption
of an existing community
• created by natural disasters or human activity
• Occurs in areas that previously contained life
and SOIL!!!
• forest fire at Yellowstone National Park.
Secondary Succession Example
• If the BHS football field is not mowed,
would it be primary or secondary
succession?
Primary or Secondary Succession?
Primary on rock Secondary on soil.
Climax Community
• Climax community: a community that has
reach a stable state.
– populations remain stable and
exist in balance with each other
and their environment
– ecosystems may reach a
point of stability that can last for
hundreds or thousands of years
Climax Community
• A climax community persists until a
catastrophic change alters or destroys a
major biotic or abiotic resource
– (ex. forest fires, abandoned farmlands, floods, areas
where the topsoil has been removed)
• After the original climax community has been
destroyed, the damaged ecosystem is likely to
recover in stages that eventually result in a
stable system similar to the original one.
Biomes
• Biome: a large region characterized by a
specific type of climate & certain plant and
animal communities.
• A certain biome may exist in more than one
location on earth.
• Biomes are terrestrial (dry) or aquatic (wet)
– Dependent on:
• Temperature
• Solar radiation
• Precipitation
Terrestrial Biomes
• Terrestrial Biomes:
– In general, six land biomes
– Characterized by climax vegetation
– Have characteristic flora (plants) and fauna
(animals)
Terrestrial Biomes: Tundra
• Climax flora: treeless.
lichens, mosses, grasses
• Climax fauna: caribou,
snowy owl
• Characteristics:
long & extremely cold winters
& permanently frozen subsoil
called permafrost
• Location:
Continuous belt around N
America, Europe & Asia
Terrestrial Biomes: Taiga
• Climax flora: conifers
or evergreen trees
• Climax fauna: moose,
black bear, squirrels
• Characteristics:
long, severe winters
• Location:
south of the tundra &
north of temperate forest
Terrestrial Biomes: TemperateDeciduous Forest
• Climax flora: trees that
shed leaves
• Climax fauna: gray
squirrel, fox, deer
• Characteristics: moderate
precipitation, cold winters,
warm summers
• Location:
South of taiga
Terrestrial Biomes: Tropical Forest
• Climax flora: many
species of broad-leaved
plants
• Climax fauna: snake,
monkey, and leopard
• Characteristics: heavy
rainfall(300 inches/year),
constant warmth
• Biodiversity:
The size of 2 football
fields may have 300
species of trees
• Location:
Near the equator
Terrestrial Biomes: Grasslands
• Climax flora: grasses
• Climax fauna: prairie dog,
bison, usually herd animals.
• Characteristics: rainfall and
temperature vary greatly,
strong winds
• Grasslands: also known as
prairies, steppes, savannas
& pampas.
• Location: interior of
continents
Terrestrial Biomes: Desert
• Climax flora: droughtresistant shrubs and
plants
• Climax fauna: kangaroo
rat, lizard
• Characteristics: sparse
rainfall (9 inches/year).
• Extreme temperature.
Hot days cool nights.
Temperatures may have
a 50 degree drop.
Aquatic Biomes
• Aquatic Biomes: the largest ecosystems
on Earth
– 70% of Earth’s surface is covered by water
– Water is the principal medium for life
– More stable then terrestrial biomes
• Moisture not a limiting factor
• Temperature changes are not as great
2 Types of Aquatic Biomes
• Marine Biomes: salt water biomes
– Most stable aquatic environment
– Habitat for large number of diverse organisms
• Freshwater Biomes: ponds, lakes, rivers
& wetlands
– Will fill in due to seasonal die-back and
erosion
– Eventually terminate in a terrestrial climax
community
Freshwater Biomes
• 2 Types of Lakes:
1. Eutrophic -rich in organic matter & vegetation
Murky water
Bacteria feed on decomposing matter &
uses up all the oxygen, killing all life.
2. Oligotrophic -little organic matter & vegetation
Clear water.
Freshwater Biomes
• Wetlands: aka swamps & marshes
an area of land that is covered by water for a
certain amount of time during the year.
Why are wetlands so important?
filters out pollutants
controls flooding
stopover for migratory birds
recreational
Zone of Photosynthesis
• Plant production occurs at the edges of land
masses
• No light penetrates the deeper regions of aquatic
biomes
Aphotic
Competition
• Competition: occurs when two different
species or organisms living in the same
environment (habitat) utilize the same
limited resources
– Examples:
• food, water, space, light, oxygen, and minerals.
• The more similar the requirements of the
organisms involved, the more intense the
competition.
Organisms in Ecosystem
• Habitat:
– A place where an organism lives out its life. It
is an organism’s home, their address.
• Niche:
- The organism's role in the community. How
an organism meets its need for food, shelter,
how it survives & reproduces. Interactions
with biotic & abiotic factors.
Material Cycles
• Material Cycles:
– In a self-sustaining ecosystem, materials must
be recycled among the organisms and the
abiotic environment.
– The same materials can be reused.
– Examples of Cycles:
• Water
• Carbon-Oxygen
• Nitrogen
Water Cycle
• Water Cycle: involves the processes of
– Photosynthesis
– Transpiration
– Evaporation and condensation
– Respiration
– Excretion
Water Cycle
Carbon-Oxygen Cycles
• Carbon-Oxygen Cycle:
involves the processes of
– Respiration
– Photosynthesis
Carbon-Oxygen Cycle
oxygen
Nitrogen Cycle
• Nitrogen Cycle:
– Organisms must have nitrogen to
produce proteins and amino acids
– Living things cannot use nitrogen gas in
the air
– Life is possible due to nitrogen-fixation
• Nitrogen Fixation: Nitrogen gas is
converted to ammonia
Nitrogen Fixers
• Legumes: peas and beans contain
nitrogen-fixing bacteria in their roots
– Clover and alfalfa are other examples of
nitrogen fixers
Bean
Plant
Alfalfa
Nitrogen Cycle
Nitrogen Gas (N2)
Nitrogen fixation
Animals
eating
plants
Decomposition
Nitrogen-fixing
bacteria in plant
roots
Soil
bacteria
Biodiversity
•
•
Evolutionary processes have resulted in a
diversity of organisms and a diversity of roles
in ecosystems.
Biodiversity: the differences in living things in
an ecosystem
1. Increased biodiversity increases the stability
of an ecosystem.
2. Increased biodiversity increases the chance that at
least some living things will survive in the face of
large changes in the environment
What are some other reasons
biodiversity is valuable?
3. Biodiversity ensures the availability of a
rich variety of genetic material that may
lead to future agricultural or medical
discoveries with significant value to
humans.
4. Biodiversity adds aesthetic qualities to
the environment
Monoculture
• Monoculture: planting one species over a
huge area
– Why?
– Leaves an area more vulnerable to predation
or disease
GLOBAL BIODIVERSITY VALUE
A map showing
the distribution
of some of the
most highly valued
terrestrial biodiversity
world-wide (mammals,
reptiles, amphibians and
seed plants), with red for
high biodiversity and
blue for low biodiversity
High Biodiversity vs. Low Biodiversity