Tropical Rainforest Biome

• •

• What:

Biomes are unique regions of the world where the climate controls what type of soil forms there, animals life there and plants grow there

• Where:

The tropical Rainforest in Amazon Basin

What aspects:

Climate, Vegetation, Soils and Animals

• Climate

• • • 3 Largest Rainforsts, South America, Africa, Asia • 5 degrees N&S of equator • Equatorial Climate • Suns angle - 90 ° to 66 ° • Direct sunlight – avg temp 27 ° - range 2 ° • Highest temp 35 ° - lowest 24 ° due to constant cloud cover • Feels hotter due to high humidity – up to 88% • Transpiration increase water vapour and high temp increases airs ability to hold water

• Rainfall always in excess of 2500mm up to 6600mm in sumatra • Rain is in short heavy downpours • Strong winds shake the canopy • Short term flooding but quickly soaks away • Amazon Basin – Ecuador, Venezuela, Peru, Bolivia and Brazil • Congo Basin, Indonesia, Northern Aus

•Soil

• Latsol – Tropical Rainforest • Poor nutrients due to leaching by heavy rains • Red in colour due to oxidation of Iron • Very short nutrient cycle • Nutrients found in living plants & decomposing plant litter ( O Horizon) • High Humidity and insects, bacteria ad fungi convert to humus quickly • Plants absorb instantly – 99% of nutrient held in plant roots

• 5-8% of sunlight reaches forest floor – undergrowth deprived of energy source • Secondary enrichment – creation of small mineral rich deposits – Chemicl weathering and percolating water concentrate amounts of precious metals e.g. Bauxite – Formed by leaching, common elements removed e.g. Calcium, silicon etc. Aluminium extremely insoluble so concentrates at surface as bauxite – Also occurs with Iron, soluble iron is washed down and concentrated as haematite

• Plant Life (Flora)

• 4 layers – Emergent, – Canopy, – Understory, – Forest floor

• Emergent – – 80m, – far apart, – umbrella shape above canopy, – smallpointed leaves as exposed to strong wind – Straight smooth branchless trunks – Butress roots (up to 9m) to support height – Hardwoods e.g. Teak & Mahogany

• Canopy – 20-40m – Thick lianas and epiphytes like mosses and orchids – Orchids get inorganic nutrients from air and rainfall and live perched on branch joints – Plant have leaves that can gather water in downpours but have drip trips to discard it before it becomes stagnant – Some leaves can turn towards sun to absorb maximum sunlight

• Understory – Less than 3% of light reaches – Dark environment – Limited growth – Short, leafy, non flowering shrubs, ferns and vines – Adapted to filtered light and poor soil

• Forest Floor – Such limited light –less than 1% of light little growth – Poor thin soils – Dense vegetation where gap in canopy – trees have fallen – Lianas cling to branches of young plants – Only most vigorous plants survive

• Large fleshy fruits develop on trunk rather than branch tips so animals can reach them • Epiphytes are plants that live on stronger plants – depend on air to bring them moisture and inorganic nutrients e.g. Orchids • Lianas – wood vines, start as small shrubs and grow up tree trunks – make up 40% of canopy leaves

• Fauna (Animal Life)

• Highly diverse • Chameleon, • jaguar, • gorilla, • macaw, • sloth, • forest elephant

• 100 species per hectare • 6km2 – – 1500 plant species – 750 tree species – 400 bird species – 250 butterfly species – 100 reptile sepcies • Larget Animals on ground floor e.g. Gorillas, Anteaters, wild boars • • Insects, spiders, birds, monkeys, reptiles and amphibians life canopy

Adaptations:

• Birds have big beaks to break nuts and tough shells e.g. Toucan & Parrot • Ability to live in trees • 27% of worlds bird species live there • Bright colour deflect heat and attract mates during mating season • Loud vocalisation- easy to communicate in dense vegetation • Diets heavy on fruit

• Camouflage – one adaptation of animals • E.g. Like a leaf • Moths and insects look dead or like leaves to hide in foliage • Abundant insects that in danger from predators e.g. Stick insects and tree frogs • Animals use colour to warn predators but some are bluffing • • Poison arrow frog and snakes – bright colour means danger

• Body structure: • Flying foxes – flap between front and back legs that allow it to glide long distances • Tail can wrap around trees for support (prehensil tail) e.g. Lemur • Sloths are covered in green algae that make them very hard to see

• Tree trunk environment – Woodpeckers drill holes in dead trees – easy and soft – Holes used as nests – Living trees also used as the sap acts as irritant for snakes trying to reach nest – Monkeys and birds also use these holes • Pollination – Plants use nectar to attract insects to aid pollination – Kapok have fluffy tops that are dispersed by the wind – – (Kapok is an emerger so it needs wide dispersal to survive)

Yanomami Tribe

• 32,000 in number • 9.6m hectares • Live in communal houses that sleep up of 400 • Men hunt – 10% of food intake • Women farm – 60 crops up of 80% of food intake • Decisions by consensus – often long debates

• 1940’s first contact with outsiders – Measles and flu killed many • 1970’s miliary govt built road through land – 2 villages wiped out by disease • 1980’s – 40,000 gold miner invaded and 20% of Yanomami died in 7yrs • Now over 1000 gold miners working illegally • Malaria is being spread and mercury is polluting rives • • Cattle ranchers invading and deforesting in eastern fringe