Amazon Rainforest Cycles

Overview

A 60-minute lesson designed for OCR A Level Geography students (typically aged 16-18) to explore the water and carbon cycles within the Amazon rainforest. This lesson aligns closely with the National Curriculum for England, focussing on curriculum aims for KS5 Geography, specifically the OCR specification on tropical rainforests, carbon and water cycles at multiple scales.

National Curriculum Links

OCR A Level Geography Specification:
- Topic: “Water and carbon cycles specific to tropical rainforests, including the rates of flow and distinct stores.”
- Understanding: “How an individual tree through to the rainforest as a whole can influence these cycles.”
National Curriculum KS5 Geography Programme of Study:
- Develop critical thinking and enquiry through application of complex geographical systems
- Analyse interactions between biophysical processes and human activity in the context of ecosystems
- Evaluate the implications of global environmental change on local and global scales

Learning Objectives

By the end of the lesson, students will be able to:

Explain the key stores and flows of water and carbon in the Amazon rainforest at the scale of an individual tree and the entire forest.
Analyse how the structure and function of the rainforest ecosystem influence these cycles.
Evaluate the interconnections and feedback mechanisms between water and carbon cycles within tropical rainforest systems.

Resources Required

Interactive whiteboard or projector
Printed or digital diagrams of the Amazon rainforest carbon and water cycles
Student worksheets (specific evaporation rates, photosynthesis data, flow rate statistics)
Plastic water bottles with soil and small plants (prepared before class) to simulate transpiration
Timer/stopwatch
Whiteboard and markers

Lesson Structure

1. Starter Activity (10 minutes)

Think-Pair-Share: The Individual Tree’s Role

Students receive a brief scenario describing an individual tree in the Amazon (e.g., a giant kapok tree).
Task: Individually jot down how this single tree can influence water and carbon cycles (transpiration, photosynthesis, carbon storage).
Students then pair up to compare ideas and consolidate understanding.
Finally, a 3-minute whole-class discussion to share diverse responses, emphasising key concepts like transpiration, interception, respiration, and carbon sequestration.

2. Input & Modelling (15 minutes)

Detailed Walkthrough of Water and Carbon Cycles at Multiple Scales

Teacher uses diagrams of the Amazon to explain:
- Water stores: biomass, soil moisture, atmosphere (humidity), rivers
- Water flows: precipitation, interception, infiltration, evapotranspiration, river flow
- Carbon stores: biomass (trees, soil), atmosphere
- Carbon flows: photosynthesis, respiration, decomposition, carbon release from deforestation
Focus on rates of flow with quantitative data (e.g., Amazon rainforest evapotranspiration can return 50-75% of rainfall back to atmosphere).
Emphasise influence of single tree (transpiration and photosynthesis) vs large-scale effects of forest as a whole (regulation of regional rainfall, carbon sink).
Use analogies such as “the forest breathes” for carbon uptake and “the lungs of the planet” to enhance memorability.

3. Practical Exploration (15 minutes)

Transpiration Simulation

In small groups of 2-3, students observe pre-prepared plastic bottles with soil and small plants wrapped with plastic bags (to simulate leaf transpiration).
Students measure condensation inside bags after 10 minutes, recording approximate water loss.
Group discussion about how this small experiment represents the scale of individual tree transpiration and how this feeds into the larger water cycle of the rainforest.
Link back to the lesson’s data on rates of flow.

4. Paired Analytical Task (10 minutes)

Cause and Effect Mapping

Using provided data and diagrams, pairs create a flow map linking the water and carbon cycles at rainforest scale.
They annotate how changes at individual tree level (e.g., logging one tree) affect the larger ecosystem cycles (e.g., reduced transpiration affecting rainfall).
Teacher circulates to support with subject-specific vocabulary (e.g., flux, sequestration, interception).

5. Plenary & Assessment (10 minutes)

Structured Reflection and Quiz

Students write a short paragraph answering:
“Explain how an individual Amazon tree influences both the water and carbon cycles, and how this role scales up to impact the whole rainforest ecosystem.”
Follow with a 5-question formative quiz (oral or digital) including:
- Multiple choice on cycle components
- Short answers on flow rates and stores
Feedback given immediately.

Differentiation

Support: Sentence starters and glossary of key terms provided for less confident writers.
Extension: Challenge students to hypothesise how climate change or deforestation might disrupt these cycles.

Assessment Criteria

Accurate use of academic geography vocabulary (e.g., evapotranspiration, carbon sequestration)
Clear explanation of flows and stores with examples from Amazon rainforest
Demonstration of multi-scale thinking from tree to forest
Effective use of cause-effect relationships in maps and paragraphs

Cross-Curricular Links

Science (Biology): Photosynthesis and ecosystems
Environmental Studies: Carbon footprint and climate change
Maths: Interpreting water flow rates and carbon measurements

Homework Suggestion

Research recent Amazon rainforest conservation projects and prepare a 2-minute presentation on how these projects aim to preserve or restore water and carbon cycle dynamics.

Teacher Reflection

Did the practical simulation enhance understanding of transpiration?
Were students able to connect micro and macro scale processes?
How effectively did students use geographic terminology in assessments?

With this lesson plan, teachers can deliver an engaging, curriculum-relevant, and memorable Geography session that supports A Level students in mastering complex interrelated rainforest systems, preparing them well for both exams and real-world geographic thinking.

Teaching Instructions