WARNING! – For TEST, study Geog File p.43, 44, 51 (sea and land breeze) & slides – After test, study Geog File p.63, 64, 65 (rainforests in depth) Test? When? Next Geog class – Wind (sea breeze / land breeze) – Location of Rainforests (where? What? Why?)

THE TROPICAL RAINFOREST

Lets recall - The climate of the Humid Tropics:- Hot – Average temperatures of >27 o C (Min 25 o C, Max 33 o C) Wet – Heavy Rainfall (Total Annual Rainfall - >1000mm, to a max of 2400mm)

What is a Forest? Why is it called a Rainforest? What is so unique about this forest? Where are these forests located? (Spatial Distribution) What has the Hot & Wet climate to do with the Tropical Rainforest? How do the plants and trees adapt to survive in this hot and wet environment? Essential Questions

Spatial Distribution of the Tropical Rainforest Amazon Rainforest Congo Basin South East Asian Rainforest Tropic of Cancer Tropic of Capricorn

Describe the distribution of the Tropical Rainforest They are located in the tropical zone, from 23.5 o N (the Tropic of Cancer) to 23.5 o S (the Tropic of Capricorn) Tropical rainforests are generally concentrated along the Equator and along the Tropic of Cancer and Tropic of Capricorn Specifically: Central South America, Central Africa and South East Asia Tropical rainforests are found in places with a hot (over 27°C) and wet (over 2000 mm) equatorial climate.

Distribution of the Tropical Rainforest Today less than 5 percent of Earth's land is covered with these forests (about 2.41 million square miles or 6.2 million km 2 ). Over half of this forest lies in Brazil, which holds about one-third of the world's remaining tropical rainforests. Another 20 percent of the world's remaining rainforest exists in Indonesia and Congo Basin, while the balance of the world's rainforests are scattered around the globe in tropical regions.

Why is it called a Rainforest 1.Rain – because it thrives in a climate with heavy rainfall of >2000mm (total annual rainfall) 2.Forest because it consists mainly of trees. Numerous species of trees together with a wide variety of plants. 3.Making the forest very dense (with foliage)

Why a forest, why not grassland? High Mean Annual Temperatures (27 o C) High temperatures (>20 o C) all year round Coupled with regular and high total annual rainfall (2000mm) Hot & Wet climate makes it very favourable for plant and tree growth. As a result, a wide variety of plants and trees are able to not only survive but thrive.

What is so unique about the Tropical Rainforest? The tropical rainforest biome is one of the most diverse and productive biomes on Earth. Tropical rainforests provide 40 percent of the oxygen on Earth even though they only cover about 6 percent of the Earth's surface. Biome = a large naturally occurring community of flora and fauna.

What is so unique about the Tropical Rainforest? Cont’d The biome is characterized by its rainfall and evergreen species. Approximately 25 percent of the medications in use today have come from tropical rainforests. Search for 10 interesting facts about the rainforest at: rainforest-biome.html

Structure of the rainforest

The arrangement of plants within a tropical rainforest is such that there are different layers and different microclimates. The diagram shows the layering of plants from the tallest emergent trees, down to the lowest ground flora. A sharp contrast exists between the two extremes. For example, the top of the forest has full light conditions and the temperature and humidity vary from o C and 60-90% relative humidity, respectively.

The Emergent layer The Emergent layer consists of the tallest and usually oldest trees which are about 40-50m high and spread out over the tops of other trees. These trees take the brunt of climatic changes e.g. they receive the highest sunlight, hottest temperatures, wind and rain. Air plants such as bromeliads grow from the trees. These specialised plants have no roots but capture moisture from the rain and nutrients from decaying leaves. Example: Seraya (Shorea Curtissi)

The Canopy layer Beneath the Emergent layer there are smaller trees 25-35m high. These trees form a living umbrella sheltering the fauna and flora below from extremes of heat, wind and rain. As there is little wind below the canopy most of the trees rely on insect, birds and bats to pollinate the flowers. Few plants rely on wind to disperse their seeds. This layer is the home to thousands of animal species such as primates and birds. These feed off the plentiful supply of berries and nuts. The abundance of life is added to by creeping plants and plants which grow on other plants such as orchids and bromeliads.

The Understorey The Understorey is the layer between the Canopy and the forest floor. It is made up of shrubs and smaller trees growing to 15m in height. The amount of sunlight to the Understorey layer is limited, as is the rainfall. This layer is also teeming with life as the Understorey provides a very sheltered environment for its inhabitants.

The forest floor/undergrowth At the forest floor humidity remains high (95% R H) and the temperature is fairly stable (20-30 o C). Less than 10% of sunlight reaches the ground. Most of the rainwater reaches the ground by flowing down the main trunks. There are many seeds lying dormant patiently waiting, sometimes for years, for a tree to fall. In this gap the seedlings will receive sufficient light, heat and water to grow regenerating the forest.

Small CrownsSmall Leaves 7-10 cm Small white fragrant flowers Winged seeds Branches out at the top Tall & straight trunks. Thin Barks Buttress roots Shorea Curtisii Seraya (40m) Shallow root system

Adaptations Biological Adaptation a. The alteration or adjustment in structure or behaviour, often occurring through natural selection, by which a species (plants and trees) become better able to function and survive in its environment. b. A structure or habit that results from this process.

Adaptive features of the plants and trees of the tropical Rainforest Parts of the plant/tree Crowns Branching Leaves Flowers Seeds Trunks Bark Roots (above ground) Roots system (below ground) Attributes/Characteristics Size Height Colour Scent Methods Thin/thick Special physical features Shallow/deep

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer Crown of treeEmergent layer Crown of treeCanopy layer

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer LeavesEmergent layer LeavesUndergrowth

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer FlowersEmergent layer FlowersUndergrowth

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer BranchingEmergent layer BranchingCanopy layer

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer Propagation (seeds)Emergent layer Propagation (spores) Undergrowth

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer Trunks Bark Emergent layer Stemsundergrowth

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer Roots (above ground) Emergent and Canopy layer

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer Roots (below ground) Emergent and Canopy layer

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer Other Features: 1. layered structure of the forest Emergent, Canopy, Understory and Undergrowth layer

Part of the plant/tree Adaptive Attribute/character istic Adapting to what aspect of the Hot /Sunlight & Wet Climate Present in which layer Any other features

My journey in becoming a self-regulated learner? Do you know what is the learning target for this lesson? ( Do you know what your need to understand – knowledge & skill) Can you go thru the slides and think about what you are reading and listening? Do you have questions as you learn? Do you know what you have learnt, un-learnt and re-learn? Answer these questions in your Geography Exercise book.