Download pyramid of biomass

BIG IDEA
• The niche of an organism determines that
organisms biotic interactions with other
organisms including its feeding relationship,
competition, & symbiosis
PRODUCERS
•aka autotrophs
•make their own food from
inorganic molecules and energy
CONSUMERS
•kinds of heterotrophs
•organisms that cannot make
their own food
CONSUMERS
HERBIVORES
•aka primary consumers
•organisms that eat only plants
•vegetarians
CONSUMERS
CARNIVORES
•aka secondary or tertiary consumers
•organisms that eat herbivores
and other carnivores
•meat eaters
CONSUMERS
OMNIVORES
•aka primary, secondary
or tertiary consumers
•organisms that eats producers
and other consumers
CONSUMERS
SCAVENGERS
•aka 1, 2, or 3 level consumers
•organisms that eats dead organisms
•usually does not hunt
•may eat plants or animals
•small aquatic ones often known as
detritivores (i.e. crabs)
DECOMPOSERS
•kinds of heterotrophs
•bacteria and fungi that consume
the bodies of dead organism and
other organic wastes
A
TROPHIC LEVEL
is a layer in the structure of
feeding relationships in an
ecosystem.
TROPHIC LEVELS
producers = 1st trophic level
consumers = 2nd trophic level
consumers = 3rd trophic level
consumers = etc… trophic level
TROPHIC LEVELS
Autotrophs are the sole
point of entry for new
energy into the ecosystem.
A
FOOD CHAIN
is a series of energy
(food) transfers between
the trophic levels of an
ecosystem
Food chains start with producers.
producer
primary
consumer secondary
consumer tertiary
consumer
A
FOOD WEB
is a network of food
chains representing the
feeding relationships
among the organisms in
a more complex system
Food webs include all the food
chains in an ecosystem
DIVERSITY & STABILITY
Some ecologists think that
an ecosystem with high
diversity and a more
complex food web is more
stable.
WHY?
WHY?
• An ecosystem with more food options will
be more diverse because if one organism
goes extinct than there are other options to
eat.
The increasing
concentration of a
pollutant in organisms
at higher trophic levels
in a food web. i.e. DDT
Energy enters an
ecosystem when
producers use sunlight to
make organic matter
through photosynthesis.
energy
Consumers take in this
energy when they eat
producers or other
consumers.
energy
energy
Most of the energy that
enters through organisms
in a trophic level does
not become biomass.
WHY NOT?
The total amount of
organic matter present
in a trophic level
only about 10% of the
energy entering one
trophic level forms
biomass in the next
trophic level.
Primary Production
• The synthesis and storage of
organic molecules during the
growth and reproduction of
autotrophs
- Measured as the rate of formation
of new material per unit of the
earth’s surface and time
• Standing crop biomass- amount
of matter found in a given area
at any point in time
• Gross Primary Production
(GPP)-refers to energy
converted by photosynthesis
• Net Primary Production (NPP)refers to energy left over after
the plant has used some of this
chemical energy for it’s own
metabolic needs (ex. Growth,
reproduction)
-plant biomass is the physical
manifestation of NPP
NPP
Global NPP
• Global NPP is the amount of energy
available to all heterotrophs
• Turnover rates- change in standing
crop biomass over time (low standing
crop, high rate of production during a
brief growing season)
ex. Grasslands and oceans (surface)
• Rates of production are determined by
climate (temp./precip.) and nutrients
• Three hundred trout are needed to
support one man for a year.
The trout, in turn, must consume
90,000 frogs, that must consume
27 million
grasshoppers that live off of 1,000
tons of grass.
Secondary Production
• The conversion of assimilated
energy into new tissue by
heterotrophs
-it is conceptually the same as the
primary production or NPP of
plants.
• Organisms vary in how efficiently
they can convert assimilated
energy into secondary production
due to widely differing metabolic
requirements.
• Homeotherms (warm-blooded)low net production efficiencies b/c
they need to maintain a constant
internal body temperature
• Poikilotherms- organisms that do
not regulate their temperatures
internally; have a higher net
production efficiency
Pyramids of Biomass, Energy, and
Numbers
• A pyramid of biomass is a
representation of the amount of
energy contained in biomass, at
different trophic levels for a given
point in time
• pyramid of numbers- represents
the number of organisms in each
trophic level
Bottom-Up vs. Top-Down Control
• bottom-up control, states that it is
the nutrient supply to the primary
producers that ultimately controls
how ecosystems function
- increase in food results in an
increase in heterotrophs
• top-down control, states that
predation and grazing by higher
trophic levels on lower trophic
levels ultimately controls
ecosystem function.
- Increase in predators = fewer
grazes resulting in more producers
Mammals are heterodont: they
have different types of teeth in
their mouths.
Other vertebrates are homodont:
meaning they have all the same
types of teeth.
MOLARS
PRE MOLARS
CANINES
INCISORS
INCISOR MODIFICATIONS
•enlargement to form chisels used for
gnawing. i.e. rats, mice
•incisors followed by a toothless gap
(diastema) i.e. rabbits
INCISOR
CANINE
What kinds
of animals
are these?
INCISOR
wolf
CANINE
bat
CANINE MODIFICATIONS
•for stabbing and holding prey
•in herbs., often reduced in size or missing
•may be weapons in displays or fighting
•in many, larger in males than in females
PREMOLARS
• usually, but not always, slightly smaller
and simpler than the molars
•are deciduous, later replaced
MOLARS
• vary tremendously in size, shape, and
function
•permanent teeth