Rainforests

Rainforests

• 1.
  Tropical RainforestsTropical Rainforests •Climate •Distributionof Rainforest •Structure of the Forest •Plant adaptations •Threats to the forest •Useful products
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  Distribution of Rainforests
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  ClimateClimate The temperature averagesThetemperature averages 28-3028-30 °C°C all year but gets warmer inall year but gets warmer in March and September when theMarch and September when the sun is not directly overhead andsun is not directly overhead and there is less cloud.there is less cloud. There is aThere is a convectional stormconvectional storm almost every afternoon except inalmost every afternoon except in March and September when,March and September when, because there is less sunshine,because there is less sunshine, there is less evaporation so thethere is less evaporation so the atmosphere is not so full ofatmosphere is not so full of moisture and there are fewermoisture and there are fewer clouds.clouds. The climate is described asThe climate is described as humidhumid
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  Climogram for Manaus,Brazil 0 50 100 150 200 250 janfeb mar apr may jun jul aug sep oct nov dec Months Precipitation(mm) 27 27.5 28 28.5 29 29.5 30 30.5 Temperature(C) Rainfall Temperature
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  Structure of theForestStructure of the Forest EmergentsEmergents CanopyCanopy Under canopyUnder canopy Shrub layerShrub layer GroundlayerGroundlayer There are 5 layers in the forestThere are 5 layers in the forest
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  Structure of theRainforestStructure of the Rainforest SHRUB LAYER UNDER CANOPY GROUND LAYER EMERGENT TREE CANOPY
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  Plant adaptationsPlant adaptations 1.Emergents and 2. the Canopy1. Emergents and 2. the Canopy Many plants haveMany plants have waxy leaveswaxy leaves andand ‘drip tips’‘drip tips’ toto allow heavy rainfall to run off.allow heavy rainfall to run off. The canopy and the emergents haveThe canopy and the emergents have buttressbuttress roots, to anchor the tree.roots, to anchor the tree. Large leavesLarge leaves and dark green foliage to maximiseand dark green foliage to maximise photosynthesisphotosynthesis.. These emergent trees grow toThese emergent trees grow to over 40mover 40m as they tryas they try to gather the maximum amount of sunlight.to gather the maximum amount of sunlight. The canopy forms aThe canopy forms a closed layerclosed layer which allows littlewhich allows little light through.light through. There is a huge amount of growth in all layers everyThere is a huge amount of growth in all layers every year.year. The increase in theThe increase in the BiomassBiomass is balanced by theis balanced by the amount of decay. This isamount of decay. This is Nutrient cyclingNutrient cycling. This can. This can be shown in abe shown in a GersmehlGersmehl Diagram. (Diagram. (see slide 15see slide 15))
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  3. The undercanopy3. The under canopy In this layer plants have to beIn this layer plants have to be shade tolerant; they have very bigshade tolerant; they have very big and very dark green leaves.and very dark green leaves. There are often few branches onThere are often few branches on the tall, straight trunks.the tall, straight trunks. Flowers are very bright to attractFlowers are very bright to attract insects; the air is too still for windinsects; the air is too still for wind pollination.pollination. There are sometimes parasiticThere are sometimes parasitic plants living on the trunks of trees:plants living on the trunks of trees: they get their food from the hostthey get their food from the host tree.tree. Many of the plants have valuableMany of the plants have valuable fruits such as Brazil nuts,fruits such as Brazil nuts, bananas, mangoes, rubberbananas, mangoes, rubber
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  4. The shrubLayer4. The shrub Layer In this layer the shrubs are bushyIn this layer the shrubs are bushy and have many stemsand have many stems Shrubs have dark green leaves atShrubs have dark green leaves at the top of the plantthe top of the plant The plants are shade tolerantThe plants are shade tolerant They often have bright flowersThey often have bright flowers which are strongly scentedwhich are strongly scented Tea, coffee and cocoa are cropsTea, coffee and cocoa are crops that grow naturally in this layerthat grow naturally in this layer
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  5. Ground Layer5.Ground Layer It is very dark on the forest floorIt is very dark on the forest floor Ferns and orchids are common plants at this level. SomeFerns and orchids are common plants at this level. Some of the plants areof the plants are parasiticparasitic.. There are many gaps between plants but it is veryThere are many gaps between plants but it is very difficult to get around due to the tangle of vines and dead,difficult to get around due to the tangle of vines and dead, fallen branches. The Litter layer is quite thick butfallen branches. The Litter layer is quite thick but Plant and animal material decays quickly in the hot,Plant and animal material decays quickly in the hot, humid conditions. This is thehumid conditions. This is the LitterLitter layer.layer.
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  Threats to theForestThreats to the Forest An area of forest the size of Belgium is clear felled for timber every year Local people have growing populations and need farmland Timber from the tall, straight trees is much sought after for building and for furniture Big business wants to extract resources from under the forest Hydro-electric schemes flood the forest Accidental fires burn out of control Satellite image of deforestation in the Amazon region, taken from the Brazilian state of Para on July 15, 1986. The dark areas are forest, the white is deforested areas, and the gray is regrowth. The pattern of deforestation spreading along roads is obvious in the lower half of the image. Scattered larger clearings can be seen near the center of the image.
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  GlossaryGlossary BiomassBiomass: Living anddead matter produced, including plants and animals. (Kg/m2/annum): Living and dead matter produced, including plants and animals. (Kg/m2/annum) CanopyCanopy: The highest layer of the rainforest, made up of the tops of trees. Animals such as: The highest layer of the rainforest, made up of the tops of trees. Animals such as howler monkeys, red-eyed tree frogs, sloths and parrots live here.howler monkeys, red-eyed tree frogs, sloths and parrots live here. EquatorEquator: An imaginary circle around the earth, equally distant at all points from the North and: An imaginary circle around the earth, equally distant at all points from the North and South poles. It divides the earth into two halves - the Northern and Southern Hemispheres.South poles. It divides the earth into two halves - the Northern and Southern Hemispheres. EmergentEmergent: The tops of the tallest trees in a rainforest.: The tops of the tallest trees in a rainforest. EvaporateEvaporate: When moisture changes from liquid to gas in the air.: When moisture changes from liquid to gas in the air. ExtractionExtraction: To remove something (for example, to take out Brazil nuts from the Amazon: To remove something (for example, to take out Brazil nuts from the Amazon rainforest).rainforest). Forest FloorForest Floor: The ground layer, made up of tree roots, soil and decaying matter. Mushrooms,: The ground layer, made up of tree roots, soil and decaying matter. Mushrooms, earthworms, and elephants all make their homes here.earthworms, and elephants all make their homes here. Greenhouse EffectGreenhouse Effect: The warming of the planet caused by chemicals which trap heat in the: The warming of the planet caused by chemicals which trap heat in the air. This process is being sped up by humans who put too many heat-trapping chemicals into theair. This process is being sped up by humans who put too many heat-trapping chemicals into the air. Some causes include car exhaust, factory smoke, and burning rainforests.air. Some causes include car exhaust, factory smoke, and burning rainforests. InterdependenceInterdependence: The concept that everything in nature is connected to each other, and: The concept that everything in nature is connected to each other, and cannot survive without the help of other plants, animals and abiotic factors (such as sun, soil,cannot survive without the help of other plants, animals and abiotic factors (such as sun, soil, water and air) around it.water and air) around it. NutrientsNutrients: Food needed for growth by living things.: Food needed for growth by living things. SpeciesSpecies: A distinct kind of plant or animal that has many common characteristics or qualities.: A distinct kind of plant or animal that has many common characteristics or qualities. SustainableSustainable: Using products of the forest in a way that does not permanently destroy them,: Using products of the forest in a way that does not permanently destroy them, so that people in the future can also use them.so that people in the future can also use them. Tropic of CancerTropic of Cancer: A circle around the earth, parallel and to the north of the equator.: A circle around the earth, parallel and to the north of the equator. Tropic of CapricornTropic of Capricorn: Similar to the Tropic of Cancer, but to the south of the equator.: Similar to the Tropic of Cancer, but to the south of the equator. UnderstoreyUnderstorey: The second layer of rainforests, made up mostly of young trees and shrubs.: The second layer of rainforests, made up mostly of young trees and shrubs. Animals that live here include jaguars, tapirs, snakes, and woodpeckers.Animals that live here include jaguars, tapirs, snakes, and woodpeckers.
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  Additional GlossaryAdditional Glossary ButtressrootsButtress roots –– wide spreading roots like scaffolding that support the very tall emergent andwide spreading roots like scaffolding that support the very tall emergent and canopy trees.canopy trees. ClimogramClimogram- a graph that shows temperature and rainfall on double axes. This is useful for- a graph that shows temperature and rainfall on double axes. This is useful for describing climate and comparing the climate of two or more places.describing climate and comparing the climate of two or more places. Convectional stormConvectional storm - rain that is the result of early evening cooling of moist air so that the- rain that is the result of early evening cooling of moist air so that the vapour condenses and a short heavy storm happensvapour condenses and a short heavy storm happens HumidHumid- the air is almost saturated with moisture and cooling a small amount will result in rainfall- the air is almost saturated with moisture and cooling a small amount will result in rainfall Nutrient CyclingNutrient Cycling – the process of material dropping to the forest floor, decaying and the– the process of material dropping to the forest floor, decaying and the nutrients being added to the soil then being taken up by plants to make new growth.nutrients being added to the soil then being taken up by plants to make new growth. ParasiticParasitic- a plant or animal that lives on and gets its food from another species- a plant or animal that lives on and gets its food from another species PhotosynthesisPhotosynthesis- the biological process that uses sunlight, water and carbon dioxide to- the biological process that uses sunlight, water and carbon dioxide to produce food for the plant and oxygen. The plants need to have Chlorophyll in their leaves for thisproduce food for the plant and oxygen. The plants need to have Chlorophyll in their leaves for this to happento happen
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  Useful Products It isdifficult to know how many useful products come from the rainforest; many species of plant and animal have yet to be studied. However we do know of many food crops such as coffee, cocoa, tea, Brazil nuts, Oil palms, coconuts etc. that are found in tropical forests and can be farmed and harvested. Raw materials such as Copra, Sisal, Hemp, Mahogony, Teak, Rubber are all rainforest crops There are huge deposits of useful minerals under the forest e.g. Iron ore, Bauxite, Gold, Silver, Tin and Diamonds The high rainfall and fast flowing rivers make Hydro Electricity cheap once the dams and generators have been installed. Many medicines such as quinine for Malaria, Aspirin and several anti- cancer drugs have been extracted from Rainforest plants.
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  Gersmehl Diagram forthe Rainforest Biomass Litter Soil Leaf fall Decay Nutrient Take up Sunlight Animal waste + Decay Water Weathered Rock Erosion Harvest Each circle represents a store of nutrients. Each arrow represents a flow of nutrients. The size of the circle is proportional to the volume of nutrients stored. The width of the arrow is proportional to the volume of nutrients flowing along that route. Back to Emergents slide