TOPIC 3B: tropical rainforests 🦜🥭

Question 1

Explain how tropical rainforests are independent ecosystems ?

Hint: abiotic and biotic characteristics

Answer 1

• tropical rainforests are independent ecosystems because:
• their biotic characteristics are related with their abiotic characteristics.

Question 2

What’s an example, of how rainforests are independent ecosystems ?

Hint: climate, grow

Answer 2

• For example, the warm and wet climate [abiotic characteristic] means that plants are able to grow quickly.
• This is because, dense leaf covers provides protection from the rainfall and root systems are what hold the soil together- stoping it from being eroded.

Question 3

What’s a second reason, why rainforests are interdependent ecosystems ?

Hint: so many

Answer 3

• [tropical] rainforests are independent ecosystems because:
• they’re so many trees in tropical rainforests.

Question 4

How does having many trees in the tropical rainforest, explain why rainforests are interdependent ecosystems ? [4]

Hint: transpiration, lots of rain, adapt

Answer 4

• it means that transpiration [water evaporating from trees] is high therefore, the majority of this transpired water, goes straight back into the clouds above tropical rainforests.
• this then causes lots of rain= this high amount of rainfall, results in nutrients being washed away [that were in the soil]
• and because of this, plants now adapt to this- by growing shallow roots, which optimises nutrient uptake, in the top organic layer

Question 5

What is the nutrient cycle ?

Hint: movement

Answer 5

• the nutrient cycle, is the cyclic movements of nutrients such as: calcium, potassium and magnesium within an ecosystem.

Question 6

What’s the Gersmehl model ?

Hint: transfer of materials

Answer 6

• the Gersmehl model, shows the transfer of material between: the vegetation and animals [biomass], soil and litter [dead vegetation]

Question 7

What are the three stores in an ecosystem, that the Gersmehl model shows ?

Answer 7

• the three stores in an ecosystem, that the Gersmehl model shows are:
• living organisms [biomass]
• dead organic material [such as fallen leaves- litter]
• and, the soil

Question 8

• Fill in the gaps: In the nutrient cycle, nutrients are transferred between _____ stores

Answer 8

• In the nutrient cycle, nutrients are transferred between three stores

Question 9

• In a nutrient cycle, what are the sizes of the circles and arrows proportional to ?

Answer 9

• In the nutrient cycle, the sizes of the circles and arrows are proportional, to the amount of nutrients

Question 10

What’s one reason, why the transfer of nutrients, is very rapid ?

Hint: evergreen

Answer 10

• the transfer of nutrients is very rapid because:
• trees are evergreen, so dead leaves and other material fall all year round

Question 11

What’s a second reason, why the transfer of nutrients, is very rapid ?

Hint: moist

Answer 11

• the warm moist climate of tropical rainforests, means that fungi and bacteria, decompose dead organic material quickly.
• this means, the nutrients released are soluble therefore, they’re soaked up the soil.

Question 12

What does soluble mean ?

Answer 12

• soluble, means able to be dissolved in water

Question 13

What’s a final reason, why the transfer of nutrients, is very rapid ?

Hint: vegetation, rapidly

Answer 13

• a final reason, why the transfer of nutrients is very rapid is because:
• dense vegetation and rapid plant growth, means that nutrients are rapidly taken up by plants’ roots.

Question 14

What is leaching ?

Hint: minerals

Answer 14

• leaching, is a process where minerals are washed away by water [usually rainfall]

Question 15

Why don’t nutrients in the nutrient cycle, penetrate into deeper soils ?

Hint: absorbed

Answer 15

• nutrients don’t penetrate into deeper soils because:
• nutrients entering the topsoil; are either quickly absorbed by plants, or washed away by the rain.

Question 16

Describe the process, of nutrient cycling [4]

Hint: rapidly grow, decays, topsoil, forest floor

Answer 16

• vegetation and trees rapidly grow and shed leaves continuously, as conditions are favourable for plant growth.
• this vegetation decays, and decomposes rapidly- due to the hot, moist conditions [and decomposers in the system.]
• nutrients then enter the topsoil; they are either quickly absorbed by plants, or washed away by the rain.
• and finally, shallow roots take up the nutrients on the forest floor, and use them to grow.

Question 17

What’s one reason, why tropical rainforests, have a high biodiversity ? [2]

Hint: around, evolve

Answer 17

• rainforests, have a high biodiversity because:
• rainforests have been around for long periods of time without the climate changing very much.
• this means, lots of time is provided for many plants and animals to evolve, and form new species- which is a reason why rainforests have a high biodiversity.

Question 18

What’s a second reason, why tropical rainforests, have a high biodiversity ? [3]

Hint: structure, adapt, different species develop

Answer 18

• rainforests, have a high biodiversity because:
• the layered structure of the rainforests, means lots of habitats are provided.
• and as a result, plants and animals adapt to become highly specialised to their particular environment, and food source.
• this means lots of different species develop, therefore resulting in tropical rainforests having a high biodiversity.

Question 19

What’s a final reason, why tropical rainforests, have a high biodiversity ? [3]

Hint: stable, biomass, consistent

Answer 19

• rainforests, have a high biodiversity because:
• rainforests are stable environments [as the climate is annually hot and wet] and they’re very productive, since plants grow continually throughout the year.
• this means, a high amount of biomass is produced because of the high rate of nutrient cycling.
• and as a result of this, animals plants have a consistent food source and don’t have to cope with changing conditions- meaning they’re able to specialise, which provides rainforests with a high biodiversity.

Question 20

What are buttress roots ?

Hint: above

Answer 20

• buttress roots, are large, thick tree roots that grow above the ground in tropical rainforests.

Question 21

How are buttress roots a plant adaptation, in the tropical rainforest’s environment ?

Answer 21

• buttress roots ensure trees [that can grow up to 40m high] are kept stable, without growing roots far down into the soil.
• this ensures the soil recieves enough air [as their roots are above ground]

Question 22

What’s a drip tip ?

Answer 22

• drip tips are tapered ends of a leaf, that allows excess rainfall to quickly drip off a leaf.
• this ensures plants are not left too wet, which can cause rotting.

Question 23

How are drip tips, a plant adaptation of the tropical rainforest environment ?

Answer 23

• drip tips are tapered ends of a leaf, that allows excess rainfall to quickly drip off a leaf.
• this means, water will run off and prevent rotting

Question 24

How is leaf structure, a plant adaptation of topical rainforest environments ?

Answer 24

• leaf structure, is a plant adaptation of topical rainforest environments because:
• many leaves have flexible stems, that move to find light.
• this is important since the dense canopy blocks light, from reaching lower levels of the rainforest.

Question 25

• Fill in the gaps: some trees have also adapted to ________ deprived, water-logged soils by growing large [buttress roots] above ______

Answer 25

• some trees have also adapted to nutrient deprived, water-logged soils by growing large [buttress roots] above ground.