rainforest (2)

Where are rainforests located?

Typically along the equator and between the two tropics; examples include Brazil, Democratic Republic of Congo, and Indonesia.

What is the climate of the rainforest?

High temperatures and high rainfall.

What are the four major characteristics of the rainforest?

High biodiversity, high temperatures, high rainfall, low nutrient soil.

Why are temperatures high in the rainforest?

Due to direct sunlight at the equator.

How does sunlight at the equator differ from the poles?

Sunlight is direct and concentrated at the equator, while at the poles, it is spread over a larger area, leading to cooler temperatures.

What is convectional rainfall?

Rainfall caused by warm air rising, cooling, and condensing into precipitation.

How does convectional rainfall occur?

The sun warms the land, causing evaporation; the moist air rises, cools, and forms rain clouds.

Why are there no distinct seasons in the rainforest?

Consistent direct sunlight year-round prevents seasonal changes.

What is the effect of no distinct seasons on rainforest ecosystems?

Allows year-round growth and reproduction, supporting high biodiversity.

What impact does high rainfall have on rainforest soil?

Leaches nutrients, making the soil nutrient-poor and thin.

What species are commonly found in the forest floor layer?

Leafcutter ants, jaguars, and various fungi.

What species inhabit the shrub layer?

Small mammals like agoutis and reptiles such as chameleons.

What species can be found in the under canopy layer?

Sloths, howler monkeys, and various birds like the toucan.

What species thrive in the canopy layer?

Spider monkeys, various parrots, and tree frogs.

What species are typically found in the emergent layer?

Eagles, bats, and butterflies like the morpho butterfly.

Why is biodiversity important in each layer?

Each layer supports unique species that contribute to the overall health of the ecosystem

What are the layers of the rainforest?

Forest floor, shrub layer, under canopy, canopy, and emergents.

What is the forest floor layer?

The bottom layer where less than 2% of sunlight reaches; rich in dead plant matter.

What is the shrub layer?

0-10m tall, home to smaller plants and animals like alligators and jaguars.

What is the under canopy layer?

10-20m tall, composed of young trees; home to sloths and howler monkeys.

What defines the canopy layer?

20-30m tall, the thickest layer, rich in biodiversity, home to many bird species and vines.

What are emergents?

The tallest trees in the rainforest (30-60m) with wide roots; home to birds and butterflies.

Why is the canopy layer important?

It houses about 80% of rainforest life due to abundant food and shelter.

How does sunlight affect the different layers?

Only a small fraction reaches the forest floor, creating low light conditions for growth

What is rainforest soil like?

Thin, nutrient-poor and high iron content.

Why is rainforest soil like that?

Because of uptake of nutrients by trees and plants, washing away of nutrients by rainfall and litter - decaying plant matter.

What is the nutrient cycle?

The process through which nutrients are recycled in the rainforest ecosystem

What are the stores in the nutrient cycle?

Biomass, litter and soil.

What happens in the flows of the nutrient cycle?

How nutrients move between the stores.

What do nutrients do in the stores?

They “sit” for a while.

Why can rainforest trees afford to lose moisture from their leaves?

Because there is so much moisture from the soil.

Why is nutrient cycling so fast in rainforests?

Because of the rapid uptake of nutrients by plants and run off by the rainfall.

What are the steps to the water cycle?

1. Heavy convectional rainfall

2. Some water is intercepted by the trees and some water reaching the ground

3. The trees take up that water

4. The trees release the water by transpiration

5. The water evaporates

Nutrient Uptake by Plants

Plants absorb nutrients from the soil.

Nutrient Addition from Biomass

Leaves fall from trees, adding nutrients to the litter layer.

Nutrient Addition from Rainfall

Rainfall can add nutrients to the litter.

Decay

Litter breaks down, transferring nutrients to the soil.

Leaching

Rainwater washes nutrients away from the soil.

Runoff

Rainwater runs along the ground, removing nutrients from the litter.

Weathering

Rocks break down, adding small amounts of nutrients to the soil.

Nutrient Uptake by Biomass

Plants draw up nutrients from the soil through their roots.

Adaptations

Features organisms have to survive in different climates.

Buttress Roots

Shallow roots that soak up nutrients and stabilize trees.

Red Leaves

Young leaves turn red to protect against sunlight while developing.

Lianas

Vines that climb other trees to access sunlight in the canopy.

Leaf Angling

Leaves arranged at different angles to avoid shading each other.

Drip Tips

Waxy leaf surfaces that allow excess rainwater to run off easily.

Epiphytes

Plants that grow on other plants to access sunlight without harming them.

Thin Bark

Allows for growth without needing to prevent moisture loss.

Pitcher Plant

Attracts and traps insects for nutrients using waxy walls and microbes.

Mimosa Pudica

Wilts its leaves when touched to scare off predators and prevent waterlogging.

Brightly Coloured Flowers

Attracts pollinators for nectar.

Challenges for Plants

High competition for sunlight and nutrients, high rainfall, low sunlight (2% at forest floor), pests, disease, and waterlogging.

Camouflage

A technique to disguise oneself to avoid predators.

Poison and Bright Colours

Bright colors deter predators; poison can kill.

Prehensile Tails

Tails that act as a fifth limb, aiding in movement in the canopy.

Picky Eating

Eating specific foods that reduce competition for resources.

Reduced Size

Smaller body size for quicker movement in limited space.

Nocturnal Living

Activity at night to avoid competition during the day.

Sloths

Use green algae for camouflage; have a triple stomach to conserve energy.

Poison Dart Frog

Small but highly poisonous, deterring predators.

Spider Monkeys

Use prehensile tails to swing through the canopy.

Toucans

Long beaks allow access to hard-to-reach fruits.

Frogs and Birds

Smaller size aids in quick movement in the rainforest.

Sloths (Nocturnal)

Avoid competition by being active at night

Rural Tribes

Indigenous communities living sustainably by hunting, fishing, and gathering.

Kayapo Tribe

Live along the Xingu River, practice subsistence farming, and use shifting cultivation.

Shifting Cultivation

Agricultural method involving clearing and burning land, then moving on as soil becomes exhausted.

Subsistence Farmers

Grow only enough crops for their own needs, without surplus for trade.

Favelas

Informal settlements where new migrants live, often resulting in deforestation for housing

Three types of Geography

human, physical, environmental

Three types of reasons

economic, social, environmental

Examples of push factors

war, politics, bad transport and/or opportunities

Examples of pull factors

positive opportunities, safety, education

Examples of intervening obstacles

visas, bodies of water and border control

Biodiversity in Rainforests

Rainforests contain about half of the existing plant and animal species in the world, including a third of the world’s bird species and 90% of its invertebrates.

Species Richness in the Rainforest

In 2.5 acres of the Amazon, there can be 300 different tree species compared to only 40 in the entire UK, along with 1,500 species of plants.

Medicinal Plants: The Role of Rainforest Flora in Modern Medicine

Medicinal Plants

Hundreds of rainforest plants are used in modern medicines; specifically, 25% of all medicines are derived from these plants.

Extinction Risk

About 20% of rainforest plant species are at risk of extinction, and only 1% have been studied. Kew Gardens is taking DNA samples to help regrow these plants.

Example of Medicinal Use

The drug Vincristine, derived from the rosy periwinkle of Madagascar, allows for 80% remission from childhood leukemia, while curare can be used as a muscle relaxant in small doses.

What is the peach palm?

The peach palm of Brazil has twice the food value of bananas and more protein than maize, highlighting the nutritional diversity of rainforest plants.

Ecological Functions: The Role of Rainforests in Erosion Control and Flood Prevention

Role in Erosion Control

The dense vegetation in rainforests catches and holds rainwater, reducing soil erosion and preventing nutrient loss during heavy downpours.

Flood Prevention

Trees help control water retention in the soil, preventing flooding. Deforestation removes this natural barrier, increasing the risk of flooding and erosion.

Indigenous Cultures: The Connection of Rainforest Tribes to Their Environment

Indigenous Tribes

Tribes have lived in rainforests for thousands of years—40,000 years in Asia and no more than 3,000 years in Africa—with around 1,000 indigenous tribes worldwide.

Sustainable Practices

Indigenous tribes have developed sustainable ways of life that utilize forest resources without causing destruction, in contrast to modern exploitation for logging, plantations, and hydroelectric projects.

Food production

80% of the world's diet originated from rainforests.

Why can conflict be caused in the rainforest?

Conflict can be caused due to disagreements of uses of rainforest land.

Users of the rainforest

• Farmers and cattle ranchers (cattle ranchers are loggers who take down the rainforest to add more space for cattle)

• Loggers

• Dam builders

• Construction workers

• Miners

• Tribes

Preventers of the rainforest

• Environmental activists

• Environmental charities

• Government

What amount of deforestation is used for cattle ranching?

80%

What is the effect of a dam on the ecosystem?

• Dams destroy ecosystems as they cause coastal erosion and loss of nutrients at the estuary.

What are three main threats of the rainforest?

Hydroelectric Dams, Mining and palm oil

Positive of hydroelectric dam

Produces electricity without greenhouse gas emissions

What do hydroelectric dams produce

Hydroelectric power using water to turn turbines and make energy

Negative of hydroelectric dam

You have to flood land to make a dam.

Case Study: How much of the tropical rainforest has been flooded by the Samuel Hydroelectric Plant?

400 million square kilometres

Mining is a threat to the rainforest because …

construction leads to deforestation to open land for said construction and human features will be added into the rainforest for the miners to live which includes: transport links, cars, houses