Transcript Ecology

Ecology
What is ecology?
• Ecology is the study of the
interactions of living organisms with
one another and with their physical
environment (soil, water, climate…)
• ECO = house
• LOGY = the study of
LEVELS OF ORGANIZATION
Species
Population
Community
Ecosystem
Biome
Biosphere
Biosphere
• The biosphere contains the
combined portions of the
planet in which all of life
exists, including land, water
and atmosphere.
ENERGY FLOW
• Every organism needs…
…ENERGY!!!
ENERGY FLOW
• What are autotrophs?
• Organisms that capture
energy from the sun or
chemicals to produce their
own food.
ENERGY FLOW
• What is a producer?
• Organisms that first
capture energy
(Autotrophs)
• FIRST TROPHIC LEVEL
ENERGY FLOW
• During photosynthesis,
autotrophs use light energy
to power chemical reactions
that convert CO2 and water
into oxygen and high energy
sugars (glucose).
PRODUCERS
LAND:
Plants
UPPER LAYERS OF OCEAN:
Algae
TIDAL FLATS/SALT MARSHES:
Photosynthetic
bacteria / cyanobacteria
CHEMOSYNTHESIS
• Chemosynthesis is the process
by which organisms use
CHEMICAL energy to
PRODUCE carbohydrates.
• Making food without sunlight!
–Example: Bacteria
ENERGY FLOW
• If AUTOTROPHS are called
PRODUCERS, because
they make their own food,
what are HETEROTROPHS
called?
CONSUMERS
• Organisms that consume plants or
other organisms to obtain energy.
• All organisms that are NOT
producers!!! (Heterotrophs)
• Three categories
– Primary
– Secondary
– Tertiary
PRIMARY CONSUMERS
• Herbivores
–Eat plants or other primary producers
• Examples
– Cows
– Horses
– Rabbits
– Some Insects
• SECOND TROPHIC LEVEL
SECONDARY CONSUMERS
• Carnivores
–Animals that eat animals
–Examples: tigers, wolves, snakes
• Omnivores
–Animals that are herbivores and
carnivores
–Examples: bears, humans
• THIRD TROPHIC LEVEL
TERTIARY CONSUMERS
• Carnivores that consume other
carnivores
• Known as “top carnivores”
• Example:
–A hawk that eats a snake
–A lion that eats a hyena
• FOURTH TROPHIC LEVEL
DETRITOVORES
• Decomposes organic
material and returns the
nutrients to the soil, water
and air (making it available
for other organisms).
• Examples: mites,
earthworms, snails, crabs
DECOMPOSERS
• Break down and absorb nutrients
from dead organisms
• They cause decay
• Decomposition of bodies and
wastes releases nutrients back into
the environment to be recycled by
other organisms.
• Examples: bacteria, fungi
SCAVENGERS
• Do not kill their food—they
search for a source of food that
is already dead
• “Clean-up” the ecosystem
• Examples: buzzards
FEEDING RELATIONSHIPS
• Energy flows through an
ecosystem in ONE direction:
Sun (or inorganic chemicals)
Autotrophs/Producers
Heterotrophs/Consumers
FOOD CHAIN
• A food chain is a series of
steps in which organisms
transfer energy by eating or
being eaten.
• It is how energy moves
through an ecosystem!
FOOD WEB
• A food web is a network of
complex interactions formed
by the feeding relationships
among the various organisms
in an ecosystem.
FOOD CHAIN vs. FOOD WEB
• A food web will link
together all of the food
chains in a particular
ecosystem…
A
terrestrial
food
chain
A
marine
food
chain
TROPHIC LEVELS
• A trophic level is a step in a food
chain or food web.
• Different organisms are on
different levels depending on their
source of energy.
• Where does energy come from?
SUN
TROPHIC LEVELS
1st TROPHIC LEVEL
Producers
2nd TROPHIC LEVEL Primary
Consumers
3rd TROPHIC LEVEL Secondary
Consumers
4th TROPHIC LEVEL Tertiary
Consumers
TROPHIC LEVELS
• A consumer in a food chain
depends on the trophic
level below it for energy.
ECOLOGICAL PYRAMIDS
• An ecological pyramid is a
diagram that show the
relative amounts of energy
or matter contained within
each trophic level of a food
chain or food web.
ECOLOGICAL PYRAMIDS
• Only part of the energy
stored in a trophic level is
passed on to the next
because organisms use
much of the energy they
con
ENERGY PYRAMID
• All energy originates from the
sun (or inorganic chemicals).
• Sunlight (radiant energy) is
converted to digestible energy
by plants during
photosynthesis.
ENERGY PYRAMID
• When the plants are eaten, the
energy is transferred to animals
to sustain life.
• Energy is transferred up the
food chain.
Tertiary
Consumers
Secondary Consumers
Primary Consumers
Producers
THE RULE OF TENS
• Only 10% of the energy in a
trophic level is passed on to the
next level…90% of the energy is
lost—where does it go?
• Given off as HEAT!!
BIOMASS PYRAMID
• Biomass is the total amount
of living tissue within a
trophic level.
• Represents the amount of
potential food available at
each trophic level.
PYRAMID OF NUMBERS
• Shows relative number of
individual organisms at each
trophic level.
LIMITATIONS OF
TROPHIC LEVELS
Why can there not be
too many links to one
food chain?
• Each trophic level can
support about one-tenth the
amount of living tissue as
the level below it, because
only 10% of the energy is
passed up!!!
A few more things…
HABITAT
• The area where an
organism lives
• Includes both biotic
and abiotic factors
Biotic vs. Abiotic
Biotic
• Bio- means: life
• Tic- means:
pertaining to
Biotic factors are the
living organisms in a
habitat!
Abiotic
• Bio- means: life
• Tic- means:
pertaining to
• A- means: no, not
Abiotic factors are all
the physical aspect of
a habitat!
Examples: soil, water,
weather
Abiotic Factors
•Water
•Air
•Soil
•Heat
•Light