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Unlock This CourseTropical forests are some of Earth's most amazing ecosystems! They're found near the equator where it's hot and wet all year round. These forests are like nature's skyscrapers - packed with life from the forest floor right up to the canopy. They're home to more than half of all the world's plant and animal species, even though they only cover about 6% of Earth's land surface.
Tropical forests are incredibly important for our planet. They help control the world's climate, produce oxygen and store huge amounts of carbon. But they're also under threat from human activities like logging and farming.
Key Definitions:
Tropical forests need specific climate conditions to thrive. They're found between 23.5°N and 23.5°S of the equator where temperatures stay between 20-28°C all year. These areas get loads of rain - usually over 2000mm per year with no real dry season. The high humidity (often 80-90%) creates perfect growing conditions for plants.
Tropical forests are like massive apartment blocks for wildlife! They have distinct layers, each with its own community of plants and animals. Understanding these layers helps us see how different species have adapted to live at different heights.
Each layer has different light levels, temperatures and humidity, creating unique mini-environments within the forest.
The giants of the forest! These trees can reach 60+ metres tall. They face strong winds and intense sunlight. Home to eagles, monkeys and butterflies. Trees here often have buttress roots for support.
The forest's roof at 30-45 metres high. This is where most forest life happens! Dense leaves block 95% of sunlight from reaching below. Sloths, parrots and countless insects live here.
The shadowy middle layer (5-20 metres). Only 2-15% of sunlight reaches here. Plants have large leaves to catch what light they can. Jaguars, frogs and snakes are common residents.
The forest floor gets less than 2% of sunlight! It's warm, humid and covered in decomposing leaves. This layer is home to army ants, termites and large mammals like tapirs. The soil is surprisingly poor because nutrients are quickly recycled by the rapid decomposition in the hot, wet conditions.
Tropical forests are biodiversity hotspots - they contain an incredible variety of life! Scientists estimate that a single hectare might contain over 300 tree species. This amazing diversity exists because of the stable climate, complex structure and millions of years of evolution.
Plants in tropical forests have developed amazing ways to survive and compete for light, water and nutrients.
Buttress Roots: Huge triangular roots that support tall trees in shallow soil. Drip Tips: Pointed leaf ends that help water run off quickly to prevent fungal growth. Lianas: Woody vines that climb trees to reach sunlight without spending energy on thick trunks.
Animals have evolved incredible features to survive in different forest layers and compete for resources.
Monkeys with long arms for swinging, prehensile tails for gripping branches and excellent colour vision for finding ripe fruits. Many have loud calls to communicate across the dense forest.
Big cats like jaguars have powerful muscles for climbing and swimming, spotted coats for camouflage and excellent night vision for hunting in the dim understory.
Many animals have evolved gliding membranes (flying squirrels, gliding frogs) or strong wings (toucans, parrots) to move efficiently between trees without touching the ground.
One of the most surprising things about tropical forests is that they grow on quite poor soils! The secret is incredibly efficient nutrient recycling. In temperate forests, nutrients are stored in the soil, but in tropical forests, most nutrients are stored in the living plants themselves.
Dead leaves and animals decompose super quickly in the hot, humid conditions - sometimes within 6 weeks! Shallow tree roots immediately absorb the released nutrients. This creates a closed loop where nutrients constantly cycle between plants and decomposers, with very little stored in the soil.
The Amazon's soils are mostly oxisols - ancient, weathered soils that are red/yellow due to iron oxides. They're acidic (pH 4-5) and low in nutrients like nitrogen and phosphorus. Despite this, the Amazon supports incredible plant growth because of efficient nutrient cycling and mycorrhizal fungi that help tree roots absorb nutrients. When forests are cleared, these poor soils can only support agriculture for a few years before becoming unproductive.
Humans have lived in and used tropical forests for thousands of years. Indigenous peoples have developed sustainable ways to use forest resources, but modern pressures are causing rapid deforestation and habitat loss.
Indigenous communities have developed sophisticated knowledge about forest ecosystems over generations.
Indigenous peoples practice shifting cultivation (slash-and-burn agriculture) where small forest areas are cleared, farmed for 2-3 years, then left to regenerate for 10-20 years. They also use hundreds of forest plants for medicine, food and materials whilst maintaining forest biodiversity.
Today's tropical forests face unprecedented threats from human activities driven by global demand for resources.
Valuable hardwoods like mahogany and teak are harvested for furniture and construction. Selective logging can be sustainable, but clear-cutting destroys entire ecosystems.
Forests are cleared for cattle ranching, palm oil plantations and soy farming. This provides short-term economic benefits but destroys biodiversity and soil quality.
Tropical forests often contain valuable minerals and oil. Mining operations can pollute rivers and destroy large forest areas, affecting both wildlife and local communities.
Protecting tropical forests is crucial for maintaining global biodiversity and climate stability. Various conservation strategies are being used, from creating protected areas to developing sustainable forest management practices.
Costa Rica lost 80% of its forests by the 1980s but has since recovered to 50% forest cover through payments for ecosystem services, ecotourism and reforestation programmes. The country pays landowners to maintain forests for their environmental benefits like carbon storage and watershed protection. This shows that forest conservation can be economically viable whilst supporting local communities.
Tropical forests are often called the "lungs of the Earth" because they produce about 28% of the world's oxygen and store massive amounts of carbon. They also influence global weather patterns and provide resources that benefit people worldwide, from medicines to climate regulation.