Download Under the canopy factsheet 12

Rainforest energy and nutrient flows
FACT SHEET 12
Precipitation
ENERGY LOST
AS HEAT
E
EN
RG
Y
FR
OM
E
TH
SU
N
Atmospheric
gases
Nutrients
used in
photosynthesis
Evaporation
Nutrient incorporation in plant
biomass
1ST TROPHIC LEVEL
Nutrients are the food materials which
plants use to promote growth.
Primary producers
Nutrients in plant
matter consumed
by animals
Energy flows
Each link where
energy flows
from one level to
another is called a
trophic level.
The process of
transfer of energy
from one trophic
level to the next is
between 5 and 20
per cent efficient.
The remaining
energy is lost as
heat.
Leaf litter
Topsoil
Subsoil
Parent rock
NPWS2015/0275
The decomposer system in the soil is
the major energy pathway of forest
ecosystem. Without the activity of soil
organism, nutrients would become locked
up and be released only by fire or slow
chemical reaction.
2ND TROPHIC LEVEL
Primary consumers
Herbivore
3RD TROPHIC LEVEL
Secondary consumers
Litterfall:
leaves and small
branches fall to
form leaf litter
Throughfall
and stem flow
Plants take up nutrients through their
roots.
Litterfall is the large amount of dead
leaves, branches, flowers and fruits
which are shed from the canopy, carrying
nutrients from the forest biomass to the
soil.
Carnivore
4TH TROPHIC LEVEL
Throughfall occurs when nutrients, mainly
potassium, are leached from leaves by rain
and carried to the forest floor. Stemflow is
water running down branches and trunks
which also removes nutrients from the
canopy to the leaf litter.
Tertiary consumers
Top carnivore
Decomposers release nutrient
from plant and animal biomass
Litter decomposition
Because of the high rate of decomposition,
the leaf litter of rainforests is not as
deep as the leaf litter of eucalypt forest,
although seasonal variation does occur.
Roots take
in nutrients
Stream discharge