Good Learning Co.
SavannahYear 8
← Geography
GeographyGCSE the living world30 min★★★ difficulty

Ecosystems and tropical rainforests

Rainforests look chaotic and are in fact tightly organised. Once you can explain nutrient cycling and adaptation, deforestation questions answer themselves.

Lesson overview

What you'll learn in this lesson

Describe ecosystems, tropical rainforests and hot deserts or cold environments, including sustainable management.

Key learning points

  • • Structure and interdependence
  • • Nutrient cycling and thin soils
  • • Deforestation: causes and impacts
  • • Sustainable management

This lesson at a glance

  • 30 minutes
  • 16 parts to scroll through
  • 4 quick checks
  • Marked quiz at the end
  • Gentle pace: short sittings with pauses

Words to know

ecosystemstropicalrainforestsdesertsenvironments

Scroll down — the lesson carries on below

Part 1 of 16 · Discover6%
1

Watch & discover

Part 1 of 16

Watch first

Ecosystems and tropical rainforests

An English teaching video on this topic from Miss Kelly. Watch it, then scroll down for the lesson.

In a nutshell

Describe ecosystems, tropical rainforests and hot deserts or cold environments, including sustainable management.

2

Learning cycle

Part 2 of 16

Learning cycle 1 of 2

Part 1 · Structure and interdependence

A short piece of teaching, then a check to make sure it has landed.

3

Explore the idea

Part 3 of 16

Learn

Structure and interdependence

Emergents, canopy, under-canopy, shrub layer and forest floor each receive different light, which drives the plants and animals found there. Climate, soil, water and living things are interdependent: remove the trees and rainfall, soil stability and nutrient supply all change together.

4

Explore the idea

Part 4 of 16

Learn

Nutrient cycling and thin soils

Almost all nutrients are stored in the biomass, not the soil. Rapid decomposition in hot, humid conditions returns nutrients to the trees within weeks, and heavy rain leaches anything left. That is why cleared rainforest land loses fertility within a few harvests.

5

Quick check

Part 5 of 16

Quick check

Where are most rainforest nutrients stored?

6

Quick check

Part 6 of 16

Quick check

Why does leaching increase after clearance?

7

Reset break

Part 7 of 16

Pause

That's sitting 1 of 2 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
8

Learning cycle

Part 8 of 16

Learning cycle 2 of 2

Part 2 · Deforestation: causes and impacts

A short piece of teaching, then a check to make sure it has landed.

9

Explore the idea

Part 9 of 16

Learn

Deforestation: causes and impacts

Commercial farming, cattle ranching, logging, mining, road building, hydroelectric schemes and population pressure all drive clearance. Impacts include biodiversity loss, soil erosion, reduced carbon storage, disrupted rainfall and displacement of indigenous communities, set against economic development, employment and export income.

10

Explore the idea

Part 10 of 16

Learn

Sustainable management

Selective logging and replanting, conservation and education, ecotourism, international debt-reduction agreements and hardwood agreements all reduce loss without ending economic use. Evaluate them by cost, enforceability and who benefits.

11

Quick check

Part 11 of 16

Quick check

Which is a sustainable management strategy rather than a cause of loss?

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Quick check

Part 12 of 16

Quick check

Which impact of deforestation is global rather than local?

13

Explore the idea

Part 13 of 16

Worked example

Model answer: 'Explain why rainforest soils lose fertility quickly after clearance' (4 marks)

In an intact rainforest almost all nutrients are held in the biomass rather than the soil, and are recycled rapidly as leaf litter decomposes in hot, humid conditions and is taken up again by the trees. When the forest is cleared, the store of nutrients is removed with the trees, so little remains to replenish the soil. Without a canopy, heavy convectional rainfall reaches the ground directly and leaches the remaining soluble nutrients downwards, so crop yields fall within a few years and farmers move on.

14

Challenge round

Part 14 of 16

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

15

Mastery quiz

Part 15 of 16

Marked quiz

End of lesson quiz: Ecosystems and tropical rainforests

4 questions, marked with the reasoning shown. No timer.

  1. 1. Where are most rainforest nutrients stored?

  2. 2. Why does leaching increase after clearance?

  3. 3. Which is a sustainable management strategy rather than a cause of loss?

  4. 4. Which impact of deforestation is global rather than local?

16

Lesson round-up

Part 16 of 16

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

Points this lesson

0

Best run

0 in a row

Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Flooding on the River Calder

The town of Harbrook sits where a steep valley opens onto a flat floodplain. In December 2015, 120 mm of rain fell in 36 hours onto ground that was already saturated. The river rose 2.4 m in five hours, and 380 homes and 54 businesses flooded. Two roads and the railway closed for eleven days.

Geographers pointed to physical causes — steep slopes, impermeable rock, heavy rainfall — and human causes: moorland drained upstream, new housing built on the floodplain, and drains designed for smaller storms.

Since then the town has planted 40 hectares of woodland upstream, built leaky dams in small streams, and raised flood walls to 1.8 m. In the storm of 2020 the peak river level was 0.3 m lower and 40 homes flooded, not 380.

Written for Good Learning Co.

Reading questions

  1. List two physical and two human causes of the 2015 flood.
  2. Explain how planting woodland upstream lowers the river's peak level.
  3. Using the figures, judge how successful the scheme has been. Quote data in your answer.

  • Case study notes

    Writing

    Write the place, the facts and the figures from this lesson so you can revise them later.

    Half a page

  • Explain answer

    Writing

    Answer in full sentences, giving causes and effects. Use one figure or place name as evidence.

    8–10 sentences

  • Map or sketch

    Diagram

    Draw the map, cross-section or field sketch with a key, title and labels, then photograph it.

    1 map with a key

  • Data work

    Working out

    Plot your figures as a graph on paper and write one sentence about the pattern.

    1 graph + 1 sentence

Saved as you type.

Part 1 of 16 · Watch & discover

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