4.  Forests have evolved over the last 420 million years  Forests account for: ◦ 1/3 of Earth’s land, ◦ Contain 70% of carbon present in living things  Forests are broadly categorised into three major types, according to their latitude: ◦ Tropical ◦ Temperate ◦ Boreal (Taiga)

6.  Found on several continents on both sides of the equator  Are a highly complex biome  Features include: ◦ Height ◦ Density ◦ Coverage ◦ Plant species ◦ Special adaptations ◦ Special relationships between plants ◦ Animal adaptations

7.  Height: Rainforest trees are usually very tall. They have few branches until the top (canopy) layer  Density: Rainforests have a high density of trees per hectare – 1 hectare of South American Rainforest may contain over 750 different types of trees  Coverage: The branches of trees link together so tight and close that the canopy is ‘closed’. Little light reaches though.

10.  Rainforests have a wide variety of plant species growing at various height levels.  Different plants ‘specialise’ at growing in different areas or ways.  These plants are so specialised that if you take them out of their specific area they will not thrive

11.  Trees developed to grow tall, straight and quick to take advantage of any gaps in the canopy  Leaf shapes allow water to drip more effectively. Without this water may never reach the ground.  Roots ‘buttress’ to help support the tree and collect more nutrients

13.  Many plants co-exist  Vines grow on trees  Orchids and staghorns catch leaf litter and pass nutrients on  Mosses, lichens and fungi break down material on forest floor and pass the nutrients along to host plants

14.  These relationships between plants are important in many ways  One way is the soil improvement: ◦ Soil is turned over by shallow roots and animal movements ◦ Drip leaves ensure eater reaches the ground ◦ Leaf litter decomposition creates fertilizer

16.  Estimated that half of all animals and insects live in tropical forests  In Brazil researchers found that a single pond contained more fish species than exist in all of Europe’s rivers.  In Peru a single tree was found to contain forty-three ant species; this is more than the total number in all of the British Isles  One-Fifth of all the worlds birds live in the Amazon rainforest  This abundance of life is due to ideal growing conditions

21.  Much of Australia was covered in rainforest  Now only comprise 2.5% of Australian forest  Over 1000 species of Australian rainforest plants, many unique  These support: ◦ thousands of insect species ◦ hundreds of reptile and bird species ◦ approximately 90 mammal species

22.  Approximately 80% of plants we eat began in tropical rainforests  About 20% of the medical drugs we use come from rainforest plants  Rainforests take in carbon dioxide and produce oxygen  Rainforests regulate the Earth’s temperature and rainfall