Download How Ecosystems Work

How Ecosystems Work
Autotrophs vs. Heterotrophs
• Autotrophs –
make their own
food so they are
called
PRODUCERS
• Heterotrophs –
get their food from
another source so
they are called
CONSUMERS
Two Main forms of Energy for
Autotrophs
• Sunlight
– The main source of
energy for life on
earth
– Photosynthesis
• Chemical
– Some organisms
such as bacteria, rely
on the energy stored
in inorganic
compounds
– Chemosynthesis
Types of Consumers Omnivores
Herbivores- only eat plants
Carnivores - only eat meat
Detritivores and
Decomposers
Feeds on plant and animal
remains
Eat plants and meat
How does Energy flow
through an Ecosystem?
• Energy flows
through an
ecosystem in ONE
direction,
– sun or chemicals
– Autotrophs
– heterotrophs
Energy Flow in Ecosystems:
Feeding Relationships
• Food Chain – steps of
organisms transferring
energy by eating &
being eaten
• Food Web – network
of all the food chains
in an ecosystem
Food Web
Ecological Pyramids
• Trophic Level – each step in a food chain or food
web
Biomass Pyramid
Energy Pyramid
Pyramid of Numbers
Pyramid of Numbers -relative number
of individuals at each trophic level
Pyramid of Biomass - amount of potential
food available for each trophic level
Pyramid of Energy - amount of energy
available at each trophic level
• Only 10% of the energy from each trophic level
is passed on to the next level
• Most of the
energy is
used by the
organisms
for life
processes
• Some of the
energy is lost
as heat
How does Matter move
through an ecosystem?
• Unlike the one way flow of
energy, matter is recycled
within & between
ecosystems
• Nutrients are passed
between
organisms & the environment
through biogeochemical
cycles
• Biogeochemical Cycles:
– Bio –life
– Geo – Earth
– Chemo – chemical
1.
WATER CYCLE
2.
NUTRIENT CYCLES:
a) CARBON
CYCLE
b) NITROGEN
CYCLE
c) PHOSPHORUS
CYCLE
Why are nutrients important ?
• Every living organism
needs nutrients to
build tissues and
carry out essential
life functions.
95% of your body is made of…
1)
OXYGEN
2)
CARBON
3)
HYDROGEN
4)
NITROGEN
THE WATER CYCLE
Water Cycle 1
• Water
– enters atmosphere by evaporation, transpiration
– leaves atmosphere as precipitation
• Water on land
– filters through ground
– runs off to lakes, rivers, ocean
Water Cycle 2
• Aquifers
– underground caverns, porous layers of rock
– store groundwater
• Runoff
– movement of surface water from land to
ocean
CARBON CYCLE
4 PROCESSES MOVE
CARBON THROUGH
ITS CYCLE:
CO2
1) Biological
2) Geochemical
3) Mixed biochemical
4) Human Activity
CO2
Carbon Cycle
• CO2 gas enters plants, algae, cyanobacteria
– photosynthesis turns CO2 into organic molecules
• Cellular respiration, combustion, erosion of
limestone return CO2 to water, atmosphere
– where it is again available to producers
NITROGEN CYCLE
N2
in Atmosphere
Nitrogen-containing nutrients in
the biosphere include:
1) Ammonia (NH3)
2) Nitrate (NO3-)
3) Nitrite (NO2-)
ORGANISMS NEED
NITROGEN TO MAKE
AMINO ACIDS FOR
BUILDING PROTEINS!!!
N03NH3
&
N02-
Nitrogen Cycle 1
• Nitrogen fixation
– conversion of nitrogen gas to ammonia
• Nitrification
– conversion of ammonia or ammonium to nitrate
Nitrogen Cycle 2
• Assimilation
– conversion of nitrates, ammonia, or ammonium
to proteins, chlorophyll, or nitrogen-containing
compounds (by plants)
– conversion of plant proteins into animal proteins
Nitrogen
Fixation
PHOSPHORUS CYCLE
PHOSPHORUS FORMS PART OF IMPORTANT LIFE-SUSTAINING
MOLECULES (ex. DNA & RNA)
Phosphorus Cycle 1
• Phosphorus erodes from rock
• Plants absorb inorganic phosphate from
soil (through roots)
• Animals obtain phosphorus from their diets
Phosphorus Cycle 2
• Decomposers release inorganic
phosphate into environment
• Phosphorus washes into ocean
– is deposited in seabeds
– lost from biological cycles for millions of years
Succession
• Succession: Changing Land, Changing
Wildlife
– To an ecologist, the term succession refers to
the predictable changes that occur in the
plants and animals that live in an area over
time.
• Pioneer species - a species which are
first to live on previously uncolonized land.
– Example: Field - grasses
Succession
• Primary succession - the series of community
changes which occur on an entirely new habitat
which has never been colonized before.
– NO SOIL
– Example: Lava flow
• Secondary succession is the series of
community changes which take place on a
previously colonized, but disturbed or damaged
habitat.
– Examples: pond, fire ecosystems (Pine Barrens)
Primary Succession Example
Coastal Sand Dunes
Secondary Succession Example
Old Field
Secondary Succession Example
NJ Pine Barrens