1. How does a tropical rainforest ecosystem function?

2. What is an ecosystem? What are the components of an ecosystem?
Abiotic components
Environment
Ecosystem
Biotic components
Plants
Animals

3. What are the biotic components in a tropical rainforest ecosystem?
Decomposers
Microscopic organisms
They may be classified into different trophic (feeding) categories.
Biotic components refer to living things.
Animals
Consumers
Producers
Plants

4. What are the biotic components in a tropical rainforest ecosystem?
1 Producers
Producers are green plants. They can produce their own food by ______________.
photosynthesis
Carbon dioxide
Water
at the presence of
Sunlight
Chlorophyll
Oxygen
Food

5. What are the biotic components in a tropical rainforest ecosystem?
2 Consumers
Tertiary consumers: feed on secondary consumers
Primary consumers: feed directly on producers
Consumers are animals. They cannot produce their own food.
Secondary consumers: feed on primary consumers

6. What are the biotic components in a tropical rainforest ecosystem?
2 Consumers
A crocodile eats animals. It is a _________.
carnivore
A rabbit eats plants only. It is a _________.
We can classify the consumers by their diet.
herbivore
Humans eat both plants and animals. They are __________.
omnivores

7. What are the biotic components in a tropical rainforest ecosystem?
2 Consumers
Rainforest tree
(Producer)
Producers and consumers make up a food chain.
A food chain usually starts with a producer and ends with a secondary consumer or tertiary consumer.
Grasshopper
(Primary consumer)
Lizard
(Secondary consumer)

8. What are the biotic components in a tropical rainforest ecosystem?
2 Consumers
In a tropical rainforest, individual food chains are interlocked at various levels to form a food web.

9. What are the biotic components in a tropical rainforest ecosystem?
3 Decomposers
Decomposers such as fungi and bacteria break down dead plant and animal tissues.
They secrete _________ to break down dead organic materials into inorganic matter. Plants can absorb them easily.
enzymes
Fungi are an example of decomposers

10. Water at the earth’s surface
What are the abiotic components in a tropical rainforest ecosystem?
Abiotic components refer to the non-living things.
They are found in:
Air
Soil
Precipitation
Water at the earth’s surface
Rocks
Solar radiation
Lithosphere
Atmosphere
Underground water
Hydrosphere

11. What are the abiotic components in a tropical rainforest ecosystem?
carbon dioxide
rivers and lakes
ground water
weathered rocks
Can you categorize the following abiotic components and state their importance to plants and animals?
oxygen
organic materials from soil
rainfall
solar radiation
Abiotic components
Atmosphere
Hydrosphere
Lithosphere
carbon dioxide
rivers and lakes
weathered rocks
rainfall
ground water
organic materials from soil
They provide drinking water and living habitats for animals.
oxygen
They provide nutrients to plants.
An input of photosynthesis of plants.
It provides water for the photosynthesis of plants.
An input of the respiration of living organisms.
An input of the photosynthesis of plants.
It provides moisture in the soil for the plants.
They provide nutrients for plants.
solar radiation

12. How are biotic and abiotic components linked in a tropical rainforest ecosystem?
Biotic and abiotic components are closely linked by:
Energy flow
Nutrient cycling

13. Why is a tropical rainforest a fragile ecosystem?
(Credit: K. Wothe/Blickwinkel)
This biomass is vulnerable to various disturbances, such as fires or deforestation.
That means a high proportion of the energy and nutrient is stored above ground.
As mentioned before, most nutrients in the tropical rainforest are stored in the biomass.

14. Why is a tropical rainforest a fragile ecosystem?
(Credit: Joerg Boethling/Still Pictures)
As the rainforests support the wildlife there, destroying the rainforest will cause the rainforest ecosystem to collapse.

15. The biomass stores most of the nutrients in a rainforest.
Why is a tropical rainforest a fragile ecosystem?
Removal of trees caused by a sudden change in climate or external agents
The biomass stores most of the nutrients in a rainforest.
Loss of stored nutrients
Collapse of the ecosystem
No supply of nutrients to the soil created through decomposition
Animals die
No regrowth of trees
Soil depletion

17. Energy flow in a tropical rainforest ecosystem
Energy flow is the transfer of energy through various living organisms along the food web.
There are five trophic levels in a tropical rainforest ecosystem. T1
Producers T2
Primary
consumers T3
Secondary
consumers
Input of solar energy T4
Tertiary
consumers
T5 Decomposers
The sun is the primary source of energy that maintains the ecosystem. Energy is passed along the food chain or food web.

18. Energy flow in a tropical rainforest ecosystem
Net input of energy at each tropic level
Energy loss through transpiration or respiration
Heat loss through respiration
Energy loss through decay and decomposition T1
Producers T2
Primary
consumers T3
Secondary
consumers
Input of solar energy T4
Tertiary
consumers
T5 Decomposers
Producers carry out photosynthesis with the input of solar energy.
Some energy is lost during the transpiration, respiration and decomposition.

19. Energy flow in a tropical rainforest ecosystem
Net input of energy at each tropic level
Energy loss through transpiration or respiration
Heat loss through respiration
Energy loss through decay and decomposition T1
Producers T2
Primary
consumers T3
Secondary
consumers
Input of solar energy T4
Tertiary
consumers
Energy not being used
T5 Decomposers
When primary consumers eat the producers as food, energy is transferred to them.
Since primary consumers cannot fully digest the producers, the remains of the producers are being processed by decomposers.

20. Energy flow in a tropical rainforest ecosystem
Net input of energy at each tropic level
Energy loss through transpiration or respiration
Heat loss through respiration
Energy loss through decay and decomposition T1
Producers T2
Primary
consumers T3
Secondary
consumers
Input of solar energy T4
Tertiary
consumers
Energy not being used
Energy not being used
Energy not being used
T5 Decomposers
The higher the tropic level (except decomposers), the ( less / more ) the energy remains.
The energy flow carries on at different tropic levels.
The energy flow carries on at different tropic levels.

21. Trophic pyramid
A trophic pyramid shows the amount of organic matter of the living organisms in an area.
As the trophic level increases, the amount of organic matter of each tropic level ( decreases / increases ).

22. Nutrient cycling in a tropical rainforest ecosystem
Nutrient cycle refers to the circulation of nutrients from the environment to organisms and back to the environment.
Environment
Organisms
Biomass
Litter
Nutrients are circulated among three stores
Soil

23. Nutrient cycling in a tropical rainforest ecosystem
Amount of nutrients transferred
Biomass
A Biomass
Biomass refers to the total weight of living organisms, i.e. plants and animals, of an area.
Nutrients are stored in plants and animals.
Uptake by plants
Plants consume nutrients from the soil and sun’s energy to produce their own tissues through photosynthesis.
Soil
When animals eat plants, they take up the nutrients and convert plant tissues to their own tissues.

24. Nutrient cycling in a tropical rainforest ecosystem
Amount of nutrients transferred
B Litter
Input dissolved in rainfall
Litter
Biomass
Littering
Loss in run-off
Dead plants tissues, dead animals and animal wastes accumulate on the ground to form a layer of litter.
The falling rain dissolves minerals, e.g. nitrogen and carbon in the air, and add the nutrients to the litter.
Some of the nutrients may be washed away by run-off.

25. Nutrient cycling in a tropical rainforest ecosystem
Amount of nutrients transferred
C Soil
Litter
Soil
Nutrients decomposed from litter
Loss through leaching
Input from weathered rock
When litter is decomposed, the nutrients are broken down into inorganic form and stored in the soil.
Weathering of rocks contributes nutrients to the soil.
Nutrients of soil may lose through leaching.

26. Nutrient cycling in a tropical rainforest ecosystem
In tropical rainforests, the nutrient store of biomass is huge, but the stores in soil and litter are small.
Biomass
Most nutrients are stored in the dense vegetation
Much input from rainfall
Quick uptake by plants
Litter
Litter is quickly decomposed
Soil
Heavy rain causes strong leaching
Amount of nutrients transferred