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Question 4: Ecosystem The Living World Unit 1 The relationship between living things (biotic) and their non living environment (abiotic/physical world). Living = Vegetation / wildlife / bacteria Non-Living = Biome A world-scale ecosystem. It is found worldwide at similar latitudes. The rainforests are one biome, Hot deserts are another. Biosphere The zone where life is found, it extends to -3m and +30m and is located between the lithosphere and the atmosphere. The Location of Ecosystems Distribution Hot Deserts Are closer to Tropics of Cancer and Capricorn. Greatest extent is in Sahara, around Egypt and Northern Africa. Approx 30º N and S Tropical Rainforests Are located close to the Equator, and are located down the wet eastern sides of the continents in the tropics. 0-20° N and S Deciduous Forests Are in temperate latitudes, they’re located further north and south on western sides of continents (warmer winters). They cover UK and much of Europe. Changing Ecosystems Global Influences that determine the Local influences that determine the type of type of ecosystem ecosystem Temperature: Affects plant growth, over the tropics the sun’s rays are higher and more concentrated meaning more plant growth. Poles they are less concentrated because they are spread out over a wider surface area. Altitude: Temperatures drop by 1°C for every 100m, causing less plants to grow. Continentality: The distance from the sea changes temperatures. Warms quickly in summer and cools quickly in winter, with increased distance Precipitation: This happens where air masses meet and rise. Air masses meet and rise to form low pressure belts that have all year round rainfall. E.G. The equator and in the UK. Nutrient-rich environments encourage plant growth. Nutrients provided by soil Geology (rock type), soils. relief, drainage of a water High-pressure belts, air descends creating dry conditions. e.g North and South Poles Seasons affect pressure belts. Climate in the key ecosystems Temperature Rainforests Hot Deserts Deciduous Forests 28°C Daily Up to 40°C Daytime 20-25°C summer temperature Above 0°C Winter Below 0°C night Rainfall (precipitation) Over 2000mm Less than 250mm 500-1500mm Of rainfall a year a year A year Rains all year Wettest March Rains all yearwettest in winter Adaptations in the key ecosystems Biome Adapted to Climate Adapted to Soil Hot Desert Saguaro Cacti have waxy reflective skin to reduce transpiration. Saguaro Cactus has wide and shallow root system to maximise water absorption Barbs to prevent consumption by animals Acacia Tree has deep tap roots (7-10m) to access ground water in dry periods Pleated stems expand to absorb rainfall during wet periods. Contract in dry periods to reduce surface area. Tropical Rainforest Grow very tall e.g. Canopy layer to compete for sunlight tall thin trunks, with few branches Trunks have wide/thick buttress roots to support trees in thin soil and to access more nutrients Drip tips to shed heavy rainfall Wide leaves to absorb sunlight Deciduous Forest Canopy trees grow very tall to compete for sunlight Herb layer flowers earlier to maximise growth before leaves block out sunlight Deep roots to reach different layers in the soil. They access minerals by breaking apart rocks and leaching them. Characteristics of vegetation Soils in the ecosystems Hot Desert : Soils are rocky, sandy and grey in colour. They are thin and can have a crust caused by impact of infrequent rainfall. Evaporation leaves salt crystals in the soil. Tropical Rainforest : Soils are red in colour and rich in iron. They are not very fertile, any nutrients are quickly washed out by heavy rainfall. Thick layer of leaf litter adds fertility as hot-humid conditions ensure it rots quickly. Deciduous Forest : Most common soil is called brown earth, which is reddish brown in colour. Every year fallen leaves decompose to ensure soils fertility. Soil is about 1 metre deep. Climate Small Scale Ecosystem- A UK Hedgerow Vegetation UK is maritime (on the coast) / temperate. This allows certain plants to grow, e.g. deciduous. Soils benefit from decomposition of organic material such as leaves which returns nutrients to the soil. Wildlife Soil Rich vegetation due to fertile soils (brown earths) found in lowland Britain. Varied vegetation provides habitats for wildlife, food, shelter and breeding. Animals help to fertilise soil and spread seeds. Food Chains and Food Webs A Food Chain is a straight line (linear). it shows what animal eats what. Plants and animals can belong to more than one food chain. A Food Web is more complex and shows how different food chains link together. It shows the transfer of energy between consumers and producers. (90% of energy is lost at each stage) Relationship: if you remove any stage of a food web, those above it will reduce in number with a declining food source. Those below it will thrive as they are no longer being eaten. Components Decomposer Breaks down waste material returning nutrients to the soil. E.G Earth Worms and bacteria Consumer Eats the stage below it in the food chain. Can be herbivores, carnivores or omnivores. Producer Uses sunlight, water and CO² to produce chemical energy through photosynthesis. All plant life. What is it? Hot Desert Tropical Rainforest Deciduous Forest A hot desert is a barren area of land where little precipitation occurs and consequently living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground. vegetation is sparse, with limited variety and there are few tall plants. There is some wildlife. There are 2 seasons - Summer and Winter. It gets very cold at night due to a lack of clouds in the sky to trap the heat in. Hot and humid, rainforest is a region of all year round growth. It has many tall trees and thick vegetation. There are a wide variety of plants species. It is continually hot and wet with storms in the afternoon. It contains a wide range of life, most of which lives in the canopy layer. There are no seasons. Cloud cover ensures it stays warm even at night. Found in temperate locations, deciduous forests are wet all year round, with a long growing season (7 months). Plants grow in layers and lose their leaves seasonally. There is a wider variety of species in the lower herb layer, this includes plant and animal life. Leaves are broad and trunks are narrow. There are 4 seasons. Causes of Deforestation in the Atlantic Forest : A tropical rainforest in Brazil Population Pressure 70% of Brazils 200 million people live around the Atlantic Forest. Growth in coastal Cities such as Rio De Janeiro and Sao Paulo has increased pressure on the forest. Rainforest areas have experienced increased clearance as the rising population seeks space for housing and farming. Many People have set up small, sometimes illegal farms, in a bid to generate incomes and provide for their families. Amerindian Tribes Many indigenous tribes live deep in the rainforest and they employ a method called ‘slash and burn’ to clear areas of trees. These tribes create a small and managed space so that they have room to farm and build their homes. First by removing trees and then burning buttresses to fertilise the soil. Because of the poor soil they have to migrate to a new location every 5 years. This is called ‘Shifting Cultivation.’ The aim is to allow the rainforest to recover without causing permanent harm. Large Scale farms and Ranching Brazil has over 1.3 trillion dollars of debt, mainly borrowed between 1965-85. These loans have forced Brazil to sacrifice its rainforest to meet repayments. Farmers were put under pressure to clear more land and produce more, to help Brazil pay its bills. Farmland is used to grow cash crops until its fertility drops then it is converted into huge cattle Ranches. Large areas of the Rainforest have also been bought by multinational companies. These companies clear the Rainforest in order to graze cattle. This means that they can then export the beef and make large profits. Mining There are many different minerals and resources that are located in the Atlantic Forest Today the forest has been scarred by opencast mining that creates a giant pit. Huge deposits of iron ore, gold, copper and tin are mined using these huge mines and lorries transport minerals for export. This provides a lot of wealth and tax income for Brazil as they sell these minerals internationally Road building In order for projects such as mines and logging to take place roads need to be built across the Rainforest, improving communications and enabling coastal exports. These roads help move products and timber around the Atlantic forest, however they are poor quality and increase the rate of deforestation. Deforestation often occurs up to 50km either side of new roads as expansion and development are uncontrolled and take advantage of improved access. Impact of deforestation on the Atlantic Forest The Consequences of deforestation (both positive and negative) Economic Local economy is boosted and jobs are created. Valuable raw materials are obtained. The country becomes more economically developed. While deforestation is economically beneficial, estimates show that conserving rainforest land is more economically viable. Brazil can use the taxes and exports to repay its $1.3 trillion debt Social People may be opposed to deforestation, but governments won’t want to stop because of the short term economic benefits. Improves communications through road building Indigenous people can continue their traditional way of life, subsistence farming. Indigenous people are lost. Five centuries ago, there were 10 million Indians in the rainforest. Now there are only 200,000. Environmental Rainforests used to cover 14% of the Earth. Now they cover 6% of it. Every second, 1.5 acres of rainforest is lost. 30% of CO2 in the last 150 years is said to be from deforestation. Local environment is polluted – dust and noise pollution. Many plant/animal species have become endangered and/or extinct. (endemic species such as the Golden Headed Lion Tamarin). 40% of tree species are endemic to the Atlantic Forest (8000). Fewer trees stop rainfall reaching the ground (interception), leading to an increased risk of flooding due to soil erosion blocking rivers. Soils become infertile due to leaching and lack of biodiversity. Political Brazil becomes over reliant on exports to generate wealth and other countries become dependent upon Brazil's mineral and agricultural exports. Managing the Atlantic Forest Setting up conservation areas – some areas of the rainforest cannot be developed on. Groups lie Conservation International have encouraged countries like Germany to invest in Brazil and establish protected areas such as National Parks. The World Bank is helping to fund conservation corridors to link up remaining areas of Atlantic Forest and enable species to move around. Eco-tourism aims to turn a rainforest into an economic resource without the need for deforestation. This provides locals with employment, educates visitors and ensures the government becomes invested in preserving the rainforest. One destination is Una Ecopark. Restoration is carried out by REGUA (Reserva Ecologica de Guapiacu),an NGO made up of local land owners and members of the community. By 2008 they had replanted 38,000 trees of 50 different species, to regenerate the rainforest ecosystem. It has set up an environmental programme for local schools. Students visit the rainforest to learn about conservation. Reducing Demand by Promoting wood that is sustainably managed or doesn’t come from rainforests. FSC, the Forest Stewardship Council, allows companies to use its logo on wood products if they promise to manage the rainforest in a responsible way so that it can recover. The ‘debt for nature swaps’ also generates income, because richer countries can reduce the debt of poorer countries by persuading them to look after the rainforest in exchange for reducing debt. Therefore, the poor country can reduce debt without having to cut down the rainforest to generate income. This is usually arranged by NGO's such as the WWF. (International Co-operation) Selective logging – only a certain number of trees per hectare can be cut down. This will ensure that some trees are kept, so the whole area will not disappear. (preserves canopy layer). However 1/3 of areas are totally cleared by illegal logging within 3 years and 30 trees can be damaged to access 1 selected tree. Deciduous forest case study – Epping Forest Epping Forest Epping Forest Epping Forest is located in south-east England, covering about 2500ha. It is managed by the City of London Corporation, which produces management plans to ensure the forest can provide for people as well as be conserved. Lots of leisure activities take place here, e.g. horse riding, running and biking. To manage the forest, trees are being pollarded (cut down to a certain height of about 2-5m), and this gives us a supply of wood but also preserves the 50,000 trees and 1200 'keystone trees', for future generations. A large proportion of the forest has been declared a site of special scientific interest, which protects the trees and animals in the area. Damaging activities, such as mountain biking are being controlled using signs to inform visitors. Use of deciduous forest for timber products (National Forest) • • • • • • • • • The National Forest was created in 1990, it is located between Leicestershire and Derbyshire. It is a new forest and over7 million trees have been planted there. All trees removed for timber are replanted to maintain the forests ecosystem. The forest supplies wood to meet Britain’s needs. 85% of woods is currently imported at a cost of £8 billion. The amount of wood created in British forests has increased to 9 million m³. Using the National Forest to supply wood products helps to develop a forest economy in the area. Woodland ‘thinnings’ are removed to prevent forest fires and are used to produce woodchips . Only more mature trees are cut down for timber to enable the forest to fully develop. Forest businesses plant and maintain the forest- pollarding and removing fallen trees allows light to reach vegetation and promote growth. Businesses extract and processing the timber to make and sell wood products. By adding value to the wood and the waste, they ensure that the area is sustainably managed for future generations. Managing deciduous forest Controlled Felling is limiting the number of trees that can be cut down Replanting, for every tree that is cut down, two or three new ones should be replanted so the forest does not decrease Conservation ensures the area is looked after and managed for future generations Planning for recreational use so the area can be used for leisure without causing permanent harm. Protection: More than 2/3rds of Epping Forest has been designated a Site of Special Scientific Interest (SSSI) and a Conservation area (SCA) This is because the plants, animals and geography of the area need to be protected for future generations. As an SCA it is given increased protection by the EU as part of global efforts to conserve the world's species. This prevents deforestation. Use of Hot Deserts Richer- Outback Covers most of central Australia • Mostly uninhabited • Home to the Aborigine Tribes Mining Most people in the outback work in mines. Australia has some of the world's largest reserves of quality iron ore, silver and gems such as opal. • Coober Pedy in South Australia is the opal capital of the world - 70% of the world's opal comes from there Mining has led to clashes with aboriginal tribes who can demand compensation as they control large areas of land in the outback Water discharged from the mining process is contaminating springs with metals and pollutants, while vegetation around the mining suffers, offering withering due to the loss of water in underground aquifers. Poorer- Sahara 1/4 of African Continent North Africa Includes a region called the Sahel Oil and gas extraction • • • The Sahara contains large reserves of oil and gas that are difficult to find and extract. Transporting the oil across the desert is equally difficult. However, Oil and gas supplies are big earners and Algeria relies on them for 50% of its GDP. The Hassi Messaoud oilfield in Algeria is a very difficult place to access but creates 40,000 jobs and pumps oil across the Sahara to the northern coastline for export. Extraction uses and contaminates underground water supplies found in aquifers. o o o Tourism Agriculture Uluru or Ayers Rock is a sacred site for the aboriginal Anangu people. The number of visitors has risen dramatically from 5000 in 1961 to 400,000 in 2005 Egypt increasingly relies on farming to feed its rising population Tourism can bring economic benefits to the local people e.g. when they buy aboriginal arts and crafts, creating jobs for local people and developing the local economy There are some problems: Aboriginal culture is often exploited and adapted to provide entertainment, tribes are losing their sense of identity and have slowly become a tourist commodity. People come for the 'experience' of the The population has increased by 59 million people in the last 25 years. 62 million of these Egyptians live in the heavily irrigated Nile Valley. - 4% of Egypt The River Nile is the main source of water and it is expected to suffer acute water shortages. There are 5.5 million hectares of farmland along the Nile sunset at the sacred rock, but may learn nothing about aboriginal culture or beliefs while they are there, often climbing or walking around the site. o o The Anangu have no role in the management or development of the tourist resort where most visitors stay and rely on the good will of tourists and signage to protect this sacred site 32% of Egyptians work on farms The building of the Aswan Dam in Egypt has prevented silt travelling down the Nile to farmland. This makes the farmland less fertile and increases the need for chemical fertilisers. It is also increasing the rate of erosion along the Nile’s banks. Farming Renewable Energy It can be difficult to make a living from farming in the outback due to the low rainfall - less than 250mm per year Just 0.3% of the Sahara's sunlight could power Europe. The soils are poor, with little organic matter to retain moisture, and plants are low in nutrients, these means crops are often poor quality and hard to grow If water is available, there's just about enough grass to feed cattle or sheep but only in quite low numbers In order for farmers to make any money the farms are huge , this leads to the development of a large areas of the desert. Over farming can lead to permanent damage with soil suffering from environmental degradation due to the loss of limited water and nutrients The lack of water also leads to farmers using complex irrigation systems that draw water from underground springs and aquifers. However, this draws up dissolved salt that increase salinity of the soil making it less fertile and more difficult for vegetation to grow Hunting and gathering 13% of Egypt's GDP comes from farming Australia's aboriginal peoples have traditionally survived by hunting and The aim is to reduce Europe's dependency on fossil fuels by using Solar Power in the Sahara. Large areas of Algeria and Tunisia will be covered in solar plants. An undersea network of power cables will use Direct Current, to transmit the energy over vast distances. The cables will cross the Mediterranean Sea. The aim is to start exporting energy to power Europe by 2018, bringing economic benefits to Algeria and Tunisia. Enough for 2 million homes. The Solar Plants will use mirrors to collect energy during the day and continue to operate at night by melting salts to power heat driven turbines gathering - finding edible plants and animals in the outback using weapons such as spears and boomerangs to catch animals such as Emu and Kangaroos They created conditions in which the grubs such as Witchetty - the Larvae of beetles, could live and breed. They built dams across rivers to catch fish, and to make pools where birds would gather to be hunted. They used fire to drive out animals for hunting, to clear wood, and to allow grass to grow. As a result, fire-tolerant plants (eucalyptus trees) came to dominate the landscape Retirement Migration People are attracted to the clean atmosphere and open spaces when looking for somewhere to retire Elderly people migrate to the Outback, where they will then retire to enjoy the freedom and change of pace They will live in newly built housing complexes, often with swimming pools and nearby luxury facilities such as golf courses. These complexes put an immense strain on the fragile ecosystem, both in terms of water consumption and power generation. Managing the challenges of Hot Deserts Richer- Outback Poorer- Sahara and the Sahel region Farming The Toshka Project Farms use dams and reservoirs to store water during dry periods. Egypt is spending $70billion to pump water from Lake Nasser to western Egypt. Farmers use boreholes to tap into underground water supplies. Argument is that not enough is being done. This helps to create 30% more fertile farmland and reduces pressure on the Nile Valley. They can grow more cash crops such as olives to increase exports and generate wealth. They can stop pumping water from underground aquifers. They can use more of the desert in a productive way. Tourism Uluru Cultural Centre helps to educate tourists about aboriginal culture and history, using photos and displays and language learning. Aboriginal guides lead walks that inform visitors about life in the desert and the significance of sacred sites. Admission fees are charged to help pay 30 employees who are responsible for the management and restoration of the area around Uluru. The Sahel is being managed using a range of methods. Reducing the number of farm animals to stop overgrazing. Mixed farming, crops and animals so that manure can be used to fertilise fields. Re-planting trees so that roots bind the soils and limit erosion. Building earth dams to collect water during wet periods and store it for dry periods. This reduces need for underground supplies that deposit salt crystals. Desertification Desertification = Over time, the quality of vegetation and soils is reduced. This causes more desert-like surfaces. Vegetation declines due to either climatic drought (which may be caused by global warming) or human removal. Less vegetation means less organic matter. The soil dries out, and the fine organic matter and mineral particles are blown away. When it rains no water reaches the soil. Impacts: Deforestation is one cause of desertification. A lack of vegetation exposes the soil, therefore causing soil erosion. Overgrazing and overcultivation can cause desertification (this is more evident in poorer parts of the world e.g. Sahel in Sahara Desert). A solution is to use crop rotation; however, many people in the Sahel may not do this as they are too poor to reduce production. Desertification can cause an increase in poverty. This is because there is no opportunity for agriculture due to the soil being infertile. Table of keywords Temperate Mild temperatures, not too hot or cold Deciduous Trees/shrubs that lose leaves seasonally Coniferous Evergreen trees, needle leaves Precipitation Water falling / rainfall Photosynthesis Turn light energy into chemical energy Humid Large amount of water Transpiration Loss of water from plants Evapotranspiration Total evaporation from plants and the land Equator Imaginary line- equal distance from polesdivides Earth Latitude How far North or South you are from the equator, measured in degrees. Tundra Low temperatures, few trees Endemic Found only in a specific location