Transcript Clip A branch of science concerned with the interrelationship of organisms and their environments.

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A branch of science concerned
with the interrelationship of
organisms and their
environments.
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Levels of
Organization
•Organism
•Population
•Community
•Ecosystem
•Biome
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Factors in the Ecosystem
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• Biotic: living influences on an
organism in the ecosystem.
Bacteria
Trees
Temperature
•Abiotic: nonliving influences
on an organism in the
ecosystem.
Sunlight
Water
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Whale
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Clock
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Water
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Fish
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Paper
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Glass
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Aluminum
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Wooden Ruler
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Sand
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Clouds
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Hair
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Copper Pipe
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Wool
Air
Snail
Steak
Pork Chops
Salad
Bread
Plant
Finger Nails
Cotton Fabric
Gold
Plastic
Grapes
Leaves
Biotic
Abiotic
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Energy Flow in an Ecosystem
• 1st law of
Thermodynamics:
• Energy cannot be
created or destroyed, it
is only changed from one
form to another
• Energy FLOWS through
an ecosystem......w/the
main source being ...
• the sun
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Producers and Consumers
• Producers:
• Plants,some algae, some bacteria
• They can make their own “food”
from the sun.
• They are also called autotrophs.
• Photoautotrophs
• Chemioautotrophes
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Cyanobacteria
Photosynthesis
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Niche
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• A niche is the role and position of a species
in its habitat.
• Essentially it is the sum of all activities and
relationships a species has while obtaining
and using the resources needed to survive
and reproduce.
• A species' niche includes:
• a. Habitat - where it lives in the ecosystem
• b. Relationships - all interactions with other
species in the ecosystem
• c. Nutrition - its method of obtaining food.
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Consumers
Organisms that cannot make their own food
are called heterotrophs.
1. Primary consumers (herbivores) feed directly on
plants or other producers.
2. Secondary consumers (carnivores) feed only on
primary consumers.
3. Tertiary or higher level consumers feed only on
animal-eating animals.
4. Omnivores can eat both plants and
animals.Examples are pigs, rats, cockroaches, and
humans.
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1. Detritivores:
(decomposers and
detritus feeders)
live off of
detritus, parts of
dead organisms
and castoff
fragments and
waste of living
organisms.
2. Decomposers :
obtain energy from
dead organic
matter
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WOW
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Amt. of
energy
decrease
with each
higher
level of
consumer
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Food Chains
• Series of steps in an ecosystem in which
organisms transfer energy by eating and
being eaten.
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Overlapping food chains.
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We’re All Connected!
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Community Interactions
•Symbiosis
•Predatory-Prey
•Competition
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Symbiosis
• “Living Together”
• 3 Types
• Mutualism
• Commensalism
• Parasitism
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Mutualism
• Both
species
benefit.
• Ex:Acacia
-ants
swarm a
katydid
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Commensalisms
One member
benefits and they
other is not helped
or harmed.
• Clown Fish
and Sea
Anemone 30
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Parasitism
one organism
benefits from the
relationship and
the other is
disadvantaged
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Predation
• Food Webs contain predator and prey
relation ships
• Can show the Energy Flow in an Ecosystem
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Review of
Community
Interactions
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Matter is Recycled!
• Unlike energy, matter is
recycled in the environment.
• Matter cycles from one
organism to another.
• Elements like nitrogen, carbon,
and phosphorus are RECYCLED
in the environment
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Biochemical Cycles
• Nutrients, the chemical
essential to life, are cycled in
the ecosystem.
• In these cycles, nutrients
move from the
environment,through
organisms, and back to the
environment.
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Nutrients are recycled in the environment.
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Nitrogen Cycle
• Nitrogen is used by living
organisms to produce a number
of complex organic molecules
like amino acids, proteins, and
nucleic acids.
• The largest amount of nitrogen
is found in the atmosphere
where it exists as a gas (mainly
N2).
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Nitrogen Fixation:
Bacteria in Plant roots convert
atm. nitrogen for the plants to use
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Carbon Cycle
• All living organisms are based on the
carbon atom.
• Ecosystems :carbon dioxide from the
atmosphere
• A number of autotrophic organisms
(PLANTS) have specialized mechanisms
that allow for absorption of this gas into
carbohydrates.
• Some of the organic matter produced in
plants is passed down to heterotrophic
animals through consumption.
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• These molecules can then be
chemically modified by these
organisms through the metabolic
addition of other elements to
produce more complex compounds
like proteins, cellulose, and amino
acids.
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Fire is important part of the Carbon
Cycle. Why?
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Falling
leaves are an
important
part of the
carbon
cycle. Why?
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Phosphorous Cycle
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• Ecosystems are constantly changing
in response to human and natural
disturbances.
• Ecological Succession is the change
that occurs.
• 2 types of succession
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Two types of succession
1.Primary Succession
2.Secondary Succession
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Primary succession
1. Begins with soil formation
2. Generally slow, many 1000s years
3. Volcanic eruptions, bare rock
4.never had a community living
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Pioneer Species
First species to
populate the area.
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SOIL
FORMATION
Pioneer Species
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Secondary Succession
• Reestablishment after
disturbance
• Faster
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• The following natural events are examples
of factors which begin secondary
succession anew:
• A) Forest Fires
• B) Disease
• C) Climatic Conditions - Hurricane,
tornado, drought, windstorms, etc........
• D) Human Disturbance - Roadsides, clear
cutting, yards, etc..........
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5th year
1st year
10th year
2nd year
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20th
year
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Primary or
Secondary?
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When forest fires burn, it
can be good and even
necessary for the forest
community as a whole. It
returns carbon to the
soil. Many plants such as
this fireweed have seeds
which lie dormant in the
soil for years until they
are heated by a forest
fire. Then they sprout.
The fire re-creates
diversity, which
strengthens the forest
by making it more
resistant to disease.
fireweed blooming
against a charred
treetrunk 63
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• Old growth
forests are
forests whose
natural cycles
of growth have
not been
disturbed by
logging,
building roads
or clearing.
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Limiting Factors in an Ecosystem
Limiting factors are
things that prevent
a population from
growing any larger.
Density-Dependent
Competition-PredationParasitismCrowding/Stress-Food,
space, nesting sites
Density-Independent
Weather-FiresDroughts/Floods-Human
activities
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Natural factors affecting Habitat
that are positive or negative
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Extreme Cold
Fires
Heavy Snow
Drought
Overpopulation
Flood
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Carrying Capacity
The maximum
number of
individuals of a
population that
can be
supported by
the
environment
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Exponential growth
In a population showing exponential growth the individuals are not limited by food or
disease.
If the rate of reproduction per individual remains constant through time, then the rate
at which the population increases is a multiple of the number of individuals in the
population.
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Logistic growth
In most real populations both food and disease become important as conditions become crowded.
There is an upper limit to the number of individuals the environment can support ("carrying
capacity“). Populations in this kind of environment show what is known as logistic growth.
A population can grow exponentially only for
short periods of time, because it would very
quickly deplete all the resources necessary for
its survival. Over long periods of time,
populations tend to attain an equilibrium
population size which is determined by the
available resources.
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Pollution
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Human impact on the environment
Air
Water
Greenhouse effect clip
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Biodiversity refers to the number and variety of
species, of ecosystems, and of the genetic
variation contained within species.
Threats to Diversity
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Over-hunting
Habitat loss
Invasion of non-native species
Pollution
Climate change
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Biome
• A group of ecosystems that have the same climate
and types of organisms.
– Climate is the average amount of rain fall and
temperatures
• Land Biomes include: Tundra, Desert, Deciduous
Forest, Taiga, Savanna, Prairie, Rainforest
• Aquatic Biomes include Freshwater and Saltwater
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Dry Biomes
• Desert – has very low
rainfall, usually hot in
the day and cold at
night, found near the
equator
• Tundra – very low
rainfall, very cold, soil
stays permanently
frozen – permafrost,
plants are very small
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Forest Biomes
• Taiga – has mostly coniferous trees (pines),
cold, most precipitation falls as snow
• Deciduous Forest – Broad Leaved trees (oaks,
hickories), has 4 seasons, good amounts of rain
(we live here)
• Rainforest – very warm, lots of rain, large
broadleaved trees that are evergreen, has the
highest biodiversity
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Grasslands
• Savanna – has grasses and occasional trees,
warm, rains for ½ year and dry for the rest
• Prairie – grasses, few trees, 4 seasons, Lots of
rain, cold winters, warm summers
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http://www.sirinet.net/~jgjohnso/ecology.html
http://bio.colstate.edu/hendricks/images/Envs1105/Autotrophs.gif
http://www.stoller-eser.com/trial/colorbook/food_web.html
http://www.willamette.edu/~broesler/riverweb/s35.jpg
http://www.arcytech.org/java/population/facts_foodchain.html
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