The rainforest ecosystem
• Where do rainforests occur?
Why is the
rainforest
both an
ecosystem
and a
biome?
A biome is
An ecosystem is
The rainforest is both because
What are the
two main
factors that
affect where
different
biomes occur?
What climatic
conditions do
rainforests
need to grow?
Productivity in the rainforest
What is the
climate of
the
rainforest?
What
causes it to
rain so
much?
Which area of the world has the sun overhead?
Which area (Africa or
Europe) did we say
had the sun directly
overhead?
Which area has the
sun spreading out
over a larger area?
Which area
is hotter then?
Why does it
rain so
much in the
rainforest?
So, based on what you have just found
out, what causes the lush vegetation in
the rainforest?
To construct pyramids of biomass: need biomass.
How do
we
measure
biomass?
To get it:
Measure mass of one organism/average of a few organisms
x total of all organisms present
Biomass = total energy within a living being
So, biomass = mass of organisms – water content
(water contains no energy and is not organic)
Weigh organisms, put in hot oven, reweigh etc
2 readings the same = finish
Measured: / unit area e.g. /m2
Can do flora or fauna
Equipment: quadrat, container, oven, weighing scales.
Why do
these four
layers
grow up?
• Does a forest
with four layers
have more or
fewer habitats
than a forest
with two layers?
• If there are more
habitats does
that mean there
are more niches?
• If there are more
niches what does
that mean about
species diversity?
Why is a rainforest so stable?
More than 50% of the world's plant and animal
species inhabit the 7% of the world that is covered in
rainforest.
A four-square mile patch of rainforest contains as
many as 1500 species of flowering plants, 750 species
of trees, 125 species of mammals, 400 species of
birds, 100 species of reptiles, 60 species of
amphibians, and 150 species of butterflies.
• Using what you now know, explain why the
rainforest has such a high species diversity.
What is primary productivity?
What is
secondary
productivity?
Definitions
Primary productivity: the energy or biomass gain by producers
per unit area per unit time
Secondary productivity: the gain in biomass by consumers per
unit area per unit time
Which one is to do with animals eating vegetation?
Which one is to do with solar energy becoming vegetation?
Which one involves photosynthesis?
Which one involved absorption by animals?
GPP = gross PP (the total gain)
NPP = net PP (the gain in energy – that lost through respiration)
Which
ecosystems
have the
greatest
gross
primary
productivity?
• What
does
this bar
graph
show
about
NPP?
What role do
the producers
(plants) have in
this ecosystem?
What role do
the
decomposers
have?
What role do
the consumers
have?
What
would
happen to
the food
web if
poachers
killed
ocelots?
How do we measure the number in a
population?
Lincoln Index
Marks animals caught
Releases them
Catches animals again
Count marked
To estimate population
Also called: capture-mark-release-recapture
N
n1
N2
M
= total no. of animals
= no. on first day
= number recaptured
= no of marked ones on 2nd day
On the ES field capture grasshoppers
Paint all of them
Release them
Recapture all grasshoppers on field
Count number of painted ones
If all the recaptured ones are painted then that
must be the whole population
How do we measure species
diversity?
Diversity means –
a) the no. of different species
b) the evenness each species
Ecosystem A 25 24 21
Ecosystem B 65 3 4
A:3.07
B:1.22
High value = diverse/stable,
low value = not diverse
Where are
nutrients
stored in
this cycle?
Where do
nutrients
come from?
How can
nutrients be
lost from
this system?
Is this the
water cycle
or the
nutrient
cycle?
Why is there so much photosynthesis
in the rainforest?
What are the inputs and outputs in
photosynthesis and respiration?
What are the
energy
transformations in
photosynthesis
and respiration?
What happens to
light energy?
Photosynthesis and respiration:
How is a tree a system?
Is it open, closed or isolated? Why?
Where does the world’s energy come from and where does it go to?
How is energy transferred and
transformed as it flows through the
rainforest ecosystem?
How is carbon
transferred and
transformed as
it moves
around the
rainforest
ecosystem?
How is nitrogen moved around the
rainforest ecosystem?
How does the water cycle work?
Water cycle
• Which of the processes are transfers and
which are transformations?
What would happen if the rain became
more acidic?
How would the productivity of the forest
change?
Water cycle
• What
happens to
the rain that
falls in a
rainforest?
• What will
happen in
the short
term if the
trees are cut
down?
• And in the
long term?