Tropical rainforests - my learning library



3429000-167005Name: …………………………………………………00Name: …………………………………………………Physical Environment – Paper 1GCSE Geography (Edexcel) REVISION Topic 3: Ecosystems, biodiversity & managementEcosystemsGlossary of key words33693102222500Revision Quiz Tropical rainforestsGlossary of key wordsRevision QuizDroughtGlossary of key wordsRevision QuizEcosystemsEcosystems can be found on a variety of scales such as a small-scale freshwater pond system or on a global scale such as the tropical rainforest biome.What is an ecosystem?An ecosystem is a natural environment and includes the flora (plants) and fauna (animals) that live and interact within that environment. Flora, fauna and bacteria are the biotic or living components of the ecosystem. Ecosystems are dependent on the following abiotic or non-living components:climate - the temperature and amount of rainfall are very important for determining what species can survive in the ecosystemsoil - the soil type is important as this provides nutrients that will support different plantswater - the amount of water available in an ecosystem will determine what plants and animals can be supportedThe biotic parts of the ecosystem, which include bacteria, flora and fauna, have a complex relationship with the abiotic components - changing one will lead to a change in the other.Changes to ecosystemsEcosystems are very sensitive to change. The living and non-living components of the ecosystem can be altered by either natural factors or human management.Changes to the ecosystem caused by natural factors include:droughtfloodfirediseaseChanges to the ecosystem caused by human management include:introducing more fish (fish stocking)altering the drainage of the land which may influence the amount of waterchanging the pH level of the wateraltering the nutrient levels of the water if fertilisers are leached into the water resulting in eutrophicationAny of these changes can have a negative impact on the ecosystem and could result in the collapse of a food chain.The global distribution of ecosystemsThe distribution of large-scale ecosystems (biomes) is determined by climate. Latitude, air pressure and winds are important factors that determine the climate of a place.Types of biomesThe map shows the distribution of the global ecosystems or biomes.Characteristics of biomesTundra - found near the North and South poles. Very few plants and animals can survive here.Taiga (coniferous forest) - found in Scandinavia, Russia and Canada. Evergreen trees thrive in this cool temperate climate.Temperate deciduous forest - found across Europe and in the USA. These trees lose their leaves every year and thrive in mild and wet conditions known as a temperate maritime climate.Temperate grassland - found in Hungary, South Africa, Argentina and the USA. Consists of grass and trees that thrive in a temperate continental climate of moderate rainfall and mild conditions.Chaparral or evergreen hardwood (Mediterranean) - found around the Mediterranean Sea, around Perth and Melbourne in Australia and California in the USA.Desert - found near the Tropics of Cancer and Capricorn. Conditions here are very hot and dry. Plants and animals are specially adapted to survive in the harsh conditions.Tropical rainforest - found near the Equator. The climate is hot and humid and many different species can be found here.Savanna grassland - found mainly in central Africa, southern India, northern Australia and central South America. Long grasses and a few scattered trees are found in these hot and dry conditions.Ecosystems change gradually between the Equator and the Poles.Distribution of UK ecosystemsOnly 18% of the UK is 'natural' ecosystems – the rest is semi-natural grasslands such as the South Downs or enclosed farmlands.Moorlands are found in upland areas, mainly in Scotland, where they make up 43% of the total land area. The Cairngorms and the Southern Uplands are an example of this kind of area. There are far fewer in England, Wales and Northern Ireland where they account for between 5% and 12% of the land area. Examples in England include the Yorkshire Moors, Exmoor and Dartmoor.Heathlands have been highly fragmented and only small, isolated areas exist in Breckland, Surrey, Hampshire and Dorset and the Lizard Peninsula in Cornwall.Only 12% of the land area of the UK is made up of woodland. 80% of these are less than 100 years old and only 5% could be considered ‘ancient’ woodlands. In England they are mainly made up of broadleaf deciduous trees such as oak and ash, whilst in Wales, Scotland and Northern Ireland the trees are mainly coniferous such as firs and pines. The largest forests are Galloway Forest Park in Scotland, Kielder Forest Park in north-east England and the New Forest in southern England.There are only 53,000 hectares of lowland raised bogs in the UK and 25,000 hectares of lowland fen. They therefore account for a very small area but have a very high biodiversity and so are very important. Key areas include the Flow Country in Scotland, Wicken Fen in East Anglia and the Inter-drumlin Fens of County Down and Armagh in Northern Ireland.Value of UK marine ecosystemsThe UK has some of the best marine ecosystems in Europe, with a wide diversity of underwater habitats and species. Many of our marine habitats and species are particularly rare and therefore of international importance, for example, the bottlenose dolphin.The Ohrid Lake trout is a highly endangered species due to overfishingThey are also a commercial resource, as fish and crustacea are worth over ?700 million a year to the UK economy. Increasingly, there is also wild foraging of halophytic plants such as samphire and kale. These are wild, shoreline plants being used more and more in high-end restaurants.These marine ecosystems are under threat from:bycatchoverfishingpollutionshippingBecause of these threats, many areas are protected. The main types of marine protected areas are:European Marine Sites - giving legal protection to species and habitats of European importanceMarine Conservation Zones and Sites of Special Scientific Interest (SSSIs) with marine components - giving protection to species and habitats of national importance Glossary of key wordsabioticNon-living elements of an ecosystem, such as climate, temperature, water, and soil type.bacteriaSingle-celled microorganisms, some of which are pathogenic in humans, animals and plants. Singular is bacterium.biomeA large-scale ecosystem. bioticLiving elements of an ecosystem, such as plants and animals.bycatchFish (or other marine animals) caught unintentionally during fishing, eg dolphins in tuna nets.climateAverage weather conditions over longer periods and over large areas.coniferousTrees that do not lose their leaves during autumn to prepare for winter.deciduousTrees that lose their leaves during autumn to prepare for winter.ecosystemThe living organisms in a particular area, together with the non-living components of the environment.eutrophication'Hyper-nutrition' resulting from fertiliser pollution of aquatic ecosystems.faunaAll the different types of animals that live in a specific area.floraAll types of plant species that live in a specific area.food chainA sequence (usually shown as a diagram) of feeding relationships between organisms, showing which organisms eat what and the movement of energy through trophic levels.leachedWhen nutrients are washed out of the soil by heavy rainfall.pH levelThe acidity level of something. A low pH level shows acidity and a high pH level shows alkalinity.speciesA type of organism that is the basic unit of classification. Individuals of different species are not able to interbreed successfully.Tropical rainforestsTropical rainforests are an important ecosystem with distinct characteristics and adaptations. Tropical rainforests face threats which need to be managed to ensure their survival.Characteristics of tropical rainforestsTropical rainforests have distinct characteristics that support a wide variety of different species. This means that they have a high biodiversity. The biotic or living components of the ecosystem and the abiotic or non-living components of the ecosystem depend on one another - a change in one leads to a change in the other.ClimateVery wet with over 2,000 mm of rainfall per year.Very warm with an average daily temperature of 28°C. The temperature never drops below 20°C and rarely exceeds 35°C.The atmosphere is hot and humid.The climate is consistent all year round. There are no seasons.SoilMost of the soil is not very fertile.A thin layer of fertile soil is found at the surface where the dead leaves decompose.It is red in colour because it is rich in iron.Due to heavy rainfall the nutrients are quickly washed out of the soil.Plants and animalsThe warm and very wet climate provides perfect conditions for plant growth.The wide range of plant species supports many different animals, birds and insects.Species have adapted to the conditions of the rainforest, eg trees and plants have shallow-reaching roots to absorb nutrients from the thin fertile layer in the soil.Structure of a tropical rainforestA tropical rainforest is made up of the following layers:ground levelshrub layerunder canopy(main) canopyemergentsAdaptationsPlant adaptationsThe following adaptations allow plants to survive in the conditions of the rainforest.Lianas - these are woody vines that have roots in the ground but climb up the trees to reach the sunlight. Their leaves and flowers grow in the canopy.Tree trunks - these are tall and thin to allow trees to reach the sunlight. The bark on these trees is smooth to allow water to flow down to the roots easily.Drip tips - plants have leaves with pointy tips. This allows water to run off the leaves quickly without damaging or breaking the leaves. Buttress roots - large roots have ridges which create a large surface area that help to support large trees. Epiphytes - these are plants which live on the branches of trees high up in the canopy. They get their nutrients from the air and water, not from the soil.Animal adaptationsMany animals have adapted to the unique conditions of the tropical rainforests.The sloth uses camouflage and moves very slowly to make it difficult for predators to spot. The spider monkey has long, strong limbs to help it to climb through the rainforest trees. The flying frog has fully webbed hands and feet, and a flap of loose skin that stretches between its limbs which allows it to glide from plant to plant. The toucan has a long, large bill to allow it to reach and cut fruit from branches that are too weak to support its weight.Importance of the tropical rainforestTropical rainforests all over the world have immense importance as they provide a life support system for the planet as well as goods and services to the people who live in the rainforests.Life support systemsTropical rainforests act as life support systems for the planet as they:Regulate the composition of the atmosphere - all tropical rainforests, such as the Amazon, regulate the composition of the atmosphere and help to offset the effect of climate change by taking in carbon dioxide through photosynthesis and releasing oxygen.Maintain soil health - in areas such as the Amazon, tropical rainforests have produced rich fertile top soils due to the rapid leaf fall and decomposition which rapidly recycles nutrients. These soils can be used to grow cassava and maize which is the staple diet of the local people.Influence the hydrological cycle - rainforests help to provide water for people. Trees act as a water store by intercepting rainfall. They release water into the atmosphere by evapotranspiration (evaporation and transpiration). This then falls again as precipitation and so gives the people living in areas such as the Amazon a constant supply of water. Tree roots also increase infiltration, allowing increased amounts of water to percolate to groundwater stores and develop aquifers.Goods and servicesTropical rainforests provide many goods and services such as:Food - rainforests can produce food such as nuts, which forms part of the diet of local people in the Amazon.Cash crops - rainforests also produce cash crops, such as the development of wild coffee that resists disease and has a higher yield than the Arabica beans traditionally used by growers in the rest of Brazil.Medicines - rainforests have also been used to search for medicines. For example, the rosy periwinkle from the rainforests of Madagascar (which can be poisonous) can help treat childhood leukaemia.Raw materials - rainforests can be logged to produce timber such as hardwoods for garden furniture exports. In Indonesia, oil palm plantations cover 7.8 million hectares and employ over 2 million people, making up 7% of Indonesia's exports, valued at $12 billion. Palm oil is used in cosmetics, confectionary, detergents and many other products.Management of tropical rainforestsTropical rainforests can be managed in the following ways to reduce deforestation:Logging and replanting - selective logging of mature trees ensures that the rainforest canopy is preserved. This method allows the forest to recover because the younger trees gain more space and sunlight to grow. Planned and controlled logging ensures that for every tree logged another is planted.Education - It is important that local people, businesses and politicians understand the true value of the tropical rainforest. Once they understand the value of biodiversity, particularly in terms of tourism, they will be more likely to want to protect it from deforestation.Ecotourism - this encourages sustainable tourism that creates jobs for local people whilst ensuring that the money generated is used to protect and conserve the tropical rainforest for future generations to enjoy.International agreements - agreements to protect tropical rainforests have been made between different countries through debt-for-nature swaps. This is when a country which is owed money by another country cancels part of the debt if an agreement is made by the debtor country to ensure the conservation of its tropical rainforests.Glossary of key wordsabioticNon-living elements of an ecosystem, such as climate, temperature, water, and soil type.aquiferNaturally occurring underground water stores.arable farmingWhen crops are grown.biodiversityThe range of animals and plants in a given area. bioticLiving elements of an ecosystem, such as plants and animals.buttress rootsA tree root that grows above the forest floor to provide nutrients and support.camouflageAn ability to blend in with a background.climate changeThe long-term alteration of weather patterns.debt-for-nature swapDebt is cancelled if a country agrees to protect its tropical rainforests.deforestationThe cutting down of trees and forests to allow a different land use.drip tipPlants with pointy tips. This allows water to run off the leaves quickly without damaging or breaking the leaves.ecotourismTourism which aims to be environmentally friendly.emergentThe tallest trees in a rainforest which benefit from more sunlight than other trees in the forest.epiphytePlants which live on the branches of trees high up in the canopy of the tropical rainforest.fertileA soil which is rich in nutrients.food webA network of food chains, showing how they all link together.global warmingThe rise in the average temperature of the Earth's surface. humidWhen the air holds a lot of moisture.hydroelectric power (HEP)Energy generated from fast-flowing water.infiltrationWater that soaks into the ground.infrastructureThe basic structures needed for an area to function, for example roads and communications. lianaA plant (vine) which grows up from the roots of trees in the rainforest.nutrient cycleCyclic movements of nutrients such as calcium, potassium and magnesium within an ecosystem.pastoral farmingWhen animals are reared, eg cows for their meat.percolateWhen water or gas filters through a surface.photosynthesisA chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy. Oxygen is produced as a by-product of photosynthesis. Algae subsumed within plants and some bacteria are also photosynthetic.predatorsAnimals that catch and eat other animals.speciesA type of organism that is the basic unit of classification. Individuals of different species are not able to interbreed successfully.sustainableAn activity which does not consume or destroy resources or the environment.DroughtsMany places around the world are affected by droughts. There are natural and man-made causes of droughts and they have an impact on different places.Characteristics of droughtsDroughts occur when there is abnormally low rainfall for an extended period of time. This means that a desert would not be considered in drought unless it had less rainfall than normal, for a long period of time. Droughts can last from weeks to months and even years.Why are some areas more vulnerable to droughts?Droughts can occur all over the world. However, there is a link between drought and some climate patterns.A lack of water vapour in the atmosphere means there is less precipitation and more chance of drought. High-pressure systems reduce evaporation and moisture in the atmosphere.El Ni?o – as the surface temperature of the Pacific Ocean around the central South American coast increases, storm patterns are disrupted. This phenomenon is thought to create droughts in Indonesia and Australia.La Ni?a - as the surface temperature of the Pacific Ocean around the central South American coast decreases, storms are again disrupted and North and South America are prone to droughts.Types of droughtsThere are three main types of drought:Meteorological drought – when the amount of precipitation received in a specific area is less than the average.Hydrological drought – when reduced precipitation impacts on water supply, eg there is decreased streamflow, soil moisture, reservoir and lake levels, and groundwater.Agricultural drought – when the above two types of drought impact on agricultural activities, eg reduced soil moisture or reservoir levels required for irrigation.Impact of human activity on droughtIt is predicted that climate change will cause some places around the world to get hotter, which will increase evaporation and some to receive less rainfall, both increase the risk of drought.Other human activities can increase the impact of drought:Agriculture – using large amounts of water to irrigate crops removes water from lakes, rivers and groundwater. Some crops require more water than others, eg cotton.Dam building – large dams can be built across a river to produce electricity and store water in a reservoir. This can reduce river water flowing downstream and cause drought below the dam.Deforestation – removing trees can reduce the amount of water stored in the soil as rain tends to fall and wash off the land as surface run-off. This leaves the ground vulnerable to erosion and desertification which can lead to drought.Why droughts are hazardousDroughts, unlike earthquakes and volcanic eruptions, are not a sudden hazard event. Instead, their beginning and end are hard to gauge and they can last for months and even years. Approximately 780 million people worldwide lack a reliable and sufficient water supply. This can have many serious impacts:A lack of clean and reliable water can cause people in developing countries to drink contaminated water which could cause a range of diseases such as cholera and mercial and subsistence farmers can experience high crop or livestock losses and a reduction in the land's value. Subsistence farmers may experience famine.With less moisture and rainfall, wildfires can become common, damaging crops, buildings and even causing death.Businesses and services which rely on clean water may be closed, eg hospitals and restaurants.Conflicts or war between people and countries can occur when pressure is put on water supplies. It can also lead to people having to migrate away from drought-stricken areas.Plus read additional info sheets in next few pages ref:Deciduous woodlandCase study: The New Forest: sustainable deciduous woodland managementGlossary of key wordsaridExtremely dry.deforestationThe cutting down of trees and forests to allow a different land use.depositionWhen material is deposited or left behind, eg when a river loses its energy and is unable to carry its load any further.desertificationThe spread of desert conditions in arid regions due to human activities, drought or climate change.evaporationThe process in which a liquid changes state and turns into a gas.famineAn extreme lack of food that leads to large numbers of people starving to death.irrigationThe channelling of water from rivers and streams to fields in order to help crops grow.marginal landLand that is difficult to develop and yields little profit.monsoonA strong seasonal wind bringing heavy rain.overgrazingWhen land cannot sustain the number of animals that are feeding from it. precipitationMoisture that falls from the air to the ground. Includes rain, snow, hail, sleet, drizzle, fog and mist.subsistence farmingWhen people only grow enough food to feed themselves and their family.surface run-offThe water that runs over the surface of the land when the soil is unable to absorb it.transpirationThe loss of water from leaves by evaporation through the stomata.Geography - Ecosystems (Quiz)What are the living components of an ecosystem?Flora, fauna and bacteriaClimate, soil and waterSolid, liquid and gas2What is the largest forest in the UK?Thetford Forest ParkKielder Forest ParkGalloway Forest Park3How much of the woodland in the UK can be considered 'ancient'?5%10%15%4Where in the UK can heathlands be found?Upland ScotlandUpland WalesBreckland, Surrey, Hampshire and Dorset5How much are marine resources worth to the UK??70 million?700 million?70 billion6What are the non-living components of an ecosystem?VegetationLichenClimate, soil and water7What factors determine the distribution of large-scale ecosystems?ClimateLatitudeAir pressure8What large-scale ecosystem would you expect to find at the Equator?Tropical rainforestsDesertsConiferous forests9What large-scale ecosystem would you expect to find 30°N and 30°S of the Equator?Tropical rainforestsDesertsTundra10What is a biome?An ecosystemA large-scale ecosystemA habitatGeography - Biodiversity QuizGeography - Tropical rainforests (Edexcel)1How much rainfall does the rainforest receive each year?2,000 mm1,000 mm1,500 mm2What is the average daily temperature in a tropical rainforest?20°C35°C28°C3What colour is the soil in the rainforest?RedOrangeBrown4How many layers make up a tropical rainforest?FourFiveSix5Where do epiphytes get their nutrients from?SoilWaterThe air and water6Where do the leaves and flowers of the lianas grow?In the emergent layerIn the canopyIn the shrub layer7Why is deforestation happening?Farming, logging, mining, road building, HEP and population growthGlobal warming, climate change and the greenhouse effectPoor weather, tropical storms and hurricanes8Which impact of deforestation could be viewed as positive?Economic developmentClimate changeNone of the impacts are positive9How can tropical rainforests be managed?Encourage cattle farming and ranchingLogging and replanting schemes, education, ecotourism and international agreementsMining and cutting down areas to make way for plantations10What is a selective management system?Selective logging of trees over a short period of timeSelective logging of young treesSelective logging of mature trees over a 40-year cycle to ensure that the rainforest has time to recoverGeography – Droughts (Quiz)Deserts occur under which type of climate system?High pressureLow pressureTropical cyclones2What is the definition of an arid area?An extremely hot areaAn extremely hostile areaAn extremely dry area3What is a meteorological drought?A drought caused by a meteor impactA drought caused by lower than expected rainfallA drought caused by higher than expected temperatures4How can humans cause droughts?By leaving taps runningBy polluting riversBy cutting down trees5Which of the following is a cause of droughts in Australia?Willy-williesThe North Atlantic DriftEl Ni?o6What is being done in Australia to help combat droughts?Using electromagnetic imaging to find underground water storesGenetically-modified cattle that require less water are being bredWater is being imported from foreign countries7Which of the following places is prone to drought hazards?ScotlandAustraliaBangladesh8What is the Sahel?A mountainous area in AsiaA narrow belt of semi-arid land immediately south of the Sahara desertA rainforest in South America9Which of the following statements about the Sahel is true?Throughout the 20th century rainfall has been below averageSince 1970, rainfall has more often than not been below averageDuring the 21st century there have been no wetter than average periods10What is being done in the Sahel to to help combat droughts?Drought-resistant crops are being introducedThey are building large dams to store waterThey have introduced hosepipe bans ................
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