| population density | the number of people in a given area usually in 1000km |
| population distribution | Where populations of people either do or do not live |
| lag phase | The period in population growth when an organism is adapting to its new environment and growth is slow |
| Log (exponential) phase | When the growth rate of a population increases rapidly over time |
| Birth rate | The total number of live births over time |
| death rate | The total number of deaths over time |
| factors affecting the birth and death rate | Countries with high death rates tend to also have high birth rates like LEDS, farming communities in LEDC’s that rely on traditional farming practices have high birth rates because more people are needed for manual labour, in MEDC’s most people live in cities and therefore do not need large families and its expensive to raise children in MEDC’, birth control is not widely used in LEDC’s because of cost, lack of access, religious practices and lack of education |
| migration | The movement of people into (immigration) or out of (emigration) a region, country or other area |
| factors affecting migration - push from rural to urban | Drought/famine, poverty, desertification, seasonal weather events, sea-level rises |
| factors affecting migration - pull from rural to urban | good supplies of food, well-paid jobs, good roads, good hospitals and schools, wide range of work |
| State the problem a country with a high birth rate (LEDC) will experience | There will be a quick rise in population meaning there won’t be enough resources and jobs to sustain good lives for these children. |
| State the problem a country with a low death rate (MEDC) will experience | Too many elders from a low death rate will mean there is not enough of a working population causing the country’s wealth to decrease. |
| difference between LEDCs and MEDCs | LEDCs - the standard of living tends to be lower, limited access to healthcare, rapid population growth
MEDCs - higher standards of living, better access to healthcare, slower population growth |
| Pronatalist policy's | in MEDC's that are experiencing population decline, the government uses various measures to boost birth rates and population growth. To ease the financial burden of raising children, they offer paid maternity leave, free daycare, progressive taxes that decrease with family size, and grants for each child born. |
| Anti-natalist policy's | Governments in LEDCs, facing population growth and financial strain, use two types of policies: mild ones like free contraception and family planning, or stricter ones like China's One Child policy, which limits the number of children per couple. |
| family planning | People use family planning to control the number and timing of their children. Governments can influence public behaviour by providing or restricting access to contraception, abortion, and IVF. Some offer free contraception, while others impose restrictions. |
| Improved health and education impacts on managing population size | It often ends in a lower death rate, which would typically cause the population to grow. But when people become more aware of contraceptive options through education, family size can be limited. Also, because they prioritize their careers over their personal lives, educated women typically marry later in life and have fewer children due to their later childbearing ages. |
| What is the percent of saline water on earth | 97% |
| what is the percent of freshwater on earth and how much of it is available for use | there is 3 percent of fresh water on earth and 1 percent of that is available for drinking, the other percent is locked up in glaciers, icecaps etc |
| water cycle | water cycle |
| aquifer | Water stored in porous rocks underneath the ground |
| well | A hole bored or dug into rock to reach the water stored there |
| reservoir | An artificial lake where water can be stored |
| domestic uses for water | washing dishes, showering, cooking |
| agricultural uses for water | Crops, animals drinking water |
| industrial uses for water | Cooling down equipment, manufacturing products |
| physical water sacristy | A situation where there physically not enough water for human needs |
| economic water sacrity | A situation in which there is enough water available, but the money does not exist to extract and/or treat enough of it for human needs |
| conditions for a dam | High rainfall = less chance of lake drying up
Existing river and large catchment system = to supply water to the dam
Impermeable surrounding rock = to stop the water from seeping out and draining away
Isolated = to minimize impact on human population, settlements, and activity |
| environmental impacts of a dam | creation of habitat for wetland species, irrigation, flood control, disrupting the life cycles of fish and other aquatic organisms |
| economic impacts of a dam | provision of water, access by boat to otherwise inaccessible areas, flooding land |
| social impacts of a dam | tourism and leisure, relocating people |
| reasons for a dam | Jobs, economic growth in industry and for domestic use, water for irrigation and livestock = farming, flood protection downstream |
| reasons against a dam | loss of fertile farmland, noise and air (dust) pollution during construction, most jobs are temporary during construction |
| sources of water pollution | domestic waste - sewage from urban and rural settlements, industrial processes and agricultural practices |
| impact of pollution of fresh water | risk of infectious bacterial diseases like typhoid and cholera, accumulation of toxic substances from industrial processes in lakes and rivers, bioaccumulation of toxic substances in food chains, nutrient enrichment leading to eutrophication |
| strategies for improving water quality | improve sanitation, treating the sewage, pollution control and legislation |
| malaria cycle | malaria cycle |
| how cholera is prevented | Good sanitation – sewage and water treatment processes in place, good hygiene and cooking of food, boiling and chlorination of contaminated water |
| how malaria is prevented - individually | avoid being outside when mosquitos are active, wearing clothing that covers most of the body, sleeping under a mosquito net that has an insecticide |
| how malaria is prevented - government | spraying insecticide inside buildings, draining wetland areas, pour oil on the surface of the water to stop the larvae from breathing and stops them from having larvae |
| how water can be made potable | boiling and chlorination |
| rock cycle | rock cycle |
| igneous rocks examples | basalt and granite |
| sedimentary rock example | limestone, sandstone, shale |
| metamorphic rock examples | marble, slate |
| geophysics of rock reading | Seismic waves are sent through the Earth’s surface. sensors are at different distances from the source of vibrations . The vibrations create shock waves that are recorded at different patterns depending on what minerals are present in the rock layers. |
| surface mining | Open-pit, open-cast/open-cut mining. Used when a valuable deposit is located near the surface, often buried below a thick layer of soil and rock (overburden) which is removed first to expose the mineral deposit and stored nearby to be used later for mine restoration. |
| bench | Benches are open pit mines. The wall of them is kept at an angle which reduces the risk of rock falls. The safe angle of these walls depends on the type of deposit and overburden |
| strip mining | It is used to mine a seam of mineral. Firstly, the overburden is removed. Strip mining is mainly used to mine coal near the surface. |
| Sub-surface mining | Deep mining, shaft mining, drift mining. Involves digging horizontal, sloping or vertical tunnels into the ground to reach deep deposits, difficult because a supply of fresh air and water drainage must be provided. Also, the dangers of collapsing tunnels. |
| the factors that need to be considered when planning to open a new mine | The costs of exploration and extraction, geology, climate, accessibility, the environmental impact, supply and demand |
| The probable cost of extraction | one tonne of ore is based on whether open-pit or shaft mining is to be used. It is cheaper to extract minerals at the surface. However, deposits of high value can be mined economically if sub-surface mining is required |
| the quality of the deposit | determines profitability and cost. High-grade ores will yield more of the required mineral than low-grade ores |
| the size of the deposit | determines the profitability. Small deposits of high-grade ore and high value ores may be worth mining, but small deposits of low-grade and low-value ores that cannot be mined at a profit may be left for when prices increase, or technological advances make it less costly to mine, thereby making them profitable at some point in the future. |
| transporting the ore | transportation from a mine to processing plants may be difficult and expensive. Cost of building road/rail or supporting infrastructure could prevent a low-grade/low-value remote deposit from being mined |
| Mining companies pay governments a tax | for extracting minerals and this needs to be fixed into a long-term agreement to avoid rapid rises in tax that could make the mining operation unprofitable |
| Changes in world demand for mineral ores | will affect price and therefore profit. Changes in supply and demand can increase and decrease profits from working mines making some deposits that could not previously be mined at a profit to become worth mining |
| Ecological impacts of mining | all mining activity will involve the loss of habitats. The plants removed, as overburden are stripped away for surface mining, or land to be used for support infrastructure for sub-surface mining and storage of waste materials, have lost a place to grow, and so have the animals that depend on the plants for food and shelter = a reduction in ecosystem biodiversity. |
| What is environmental impact assessment? | A process by which the probable effects on the environment of a development are assessed and measured. |
| when is an environmental impact assessment carried out and why | When a company applies for a license to start working, the license application is usually approved if the company has a plan to keep the loss of habitat as small as possible and then to restore the land after mining has finished. |
| impact of noise pollution | Noise pollution is a problem when large-scale surface mining takes place. The overburden is loosened by explosive charges and then removed by large machines. The noise can disturb the behaviour of many animal species near them. Deep mining usually produces less noise than surface mining. Mining licenses set limits on the levels of noise and working hours of a mine. |
| impact of water pollution on mines | Can be a big problem that lasts for years. The water that drains through mine waste, or comes directly from mine shafts, can cause changes to the populations of living organisms in streams and rivers. It could be unsafe for people to drink. The water may become acidic and combined with lots of toxic metal ions kills many aquatic organisms. |
| impact of land pollution | Mine waste will pollute the land surrounding it. The area can be quite small but the toxic nature of the waste means that only a few plants can grow, even years later. When mine waste is stored above natural water courses, the waste pile may collapse and cover more land. Many mining activities release dust particles, which will settle on the vegetation near the mine. Dust reduces plant growth: the leaves of plants need to absorb light energy to perform photosynthesis and dust may prevent this |
| impact of air pollution | Dust from mining activities may also have toxic effects depending on the chemical components present in the dust. This can reduce or stop plant growth and can be dangerous to human health because breathing in the dust can give lung disease especially to children, it can also be absorbed through human skin. Mining companies provide protective clothing to mine workers. However, many people make a living from small-scale mining without a license, which is illegal. Health problems are likely for these miners. |
| impact of visual pollution | Evidence of mining activity can often be seen because the landscape is damaged. Large-scale surface mining will create the most obvious visual pollution during the working life of a mine. This type of pollution may only be temporary because careful restoration of the landscape is possible. |
| reasons why illegal mining without a license is bad | Mining without a license is bad for people as they can inhale the dust particles which can result in death or lung cancer. For the government and environment, mining can be bad as it causes deforestation, soil erosion, and general pollution. It is much harder to hold illegal mining companies accountable for the damage they cause. |
| economic impacts of mines | employment and taxes. Mining benefits both local and national economies. Employment increases spending and provides taxes for investment in infrastructure projects. Jobs are created to extract minerals and to supply transport and mining equipment. Some improvements to transport and services, will be required to supply any mining industry (as a condition of their mining license) as well as support the mineworkers and their families. |
| Safe disposal of mining waste | one of the most important aspects of any mining license application within a well-regulated system. Safe storage and monitoring of waste piles to prevent collapse and water pollution must be part of a detailed mining plan. |
| how land restoration can be achieved after a mining | The waste can then be covered by a layer of soil, which may be enriched with fertilizer. An area could then be planted with trees (creates habitats quickly), which will help other plants and animals to come. As time passes, the soil will be improved by the addition of organic matter from plant and animal wastes. This method is often used to manage the waste from coal mining. |
| how bioremediation is used within the mining industry | Many organisms can break down toxic substances into less hazardous substances. This often happens slowly in natural environments. Some microorganisms, such as bacteria found in soils, can absorb pollutants and process them into less harmful substances, this can happen at a faster rate if their environment provides a source of oxygen and nitrogen. Some mine waste does not allow the growth of tree roots, so other methods of restoration must be used, alternatively waste can be removed from a site to a treatment plants. |
| how are nature reserves used after mining | Several tree and herb species are introduced, and as the plant populations grow, they create habitats for many animal species which help to maintain biodiversity. |
| how are reservoirs used after mining | If the rock lining the hole is impervious to water and non-toxic, then it can be allowed to fill with water to form a reservoir or a lake. This water could be used for irrigating farmland or processed to provide clean, safe drinking water for humans. Can be used as a landfill site |
| Sustainable development | The use and development of rock and mineral reserves must consider environmental, economic, and social factors. The goal is to plan and control the reserve to maximize benefits for people, maintain economic growth and stability, and prevent widespread environmental damage. |
| sustainability | use that meets the needs of the present without affecting the ability of future generations to meet their needs |
| efficiency/sustainability of extraction | Mine wastes are reprocessed to remove remaining valuable materials. Improved machine performance and increased use of computer data analysis have also boosted extraction efficiency. |
| efficiency/sustainability of use through recycling | makes an important contribution to the sustainable use of rocks and minerals. Many manufactured goods (cars, steel cans, plastics, glass bottles), are recycled. Most metals can be recovered and refined back to clean metals to be used by industries again. |
| efficiency/sustainability of use through substitution | means that it may be possible to find substitutes for the use of relatively scarce materials |
| efficiency/sustainability of use through new technologies | using engineering solutions to make products so that less is used for the same purpose |
| efficiency/sustainability of use through durability | making products that last longer before they are recycled. Manufacturers will in the future be required by law to take back their products when they are finished with. It is hoped this will encourage them to make more durable products that use less minerals and last longer |
| why energy demand is increasing | increasing population size, increasing industrialization and urbanization, improvements in standards of living and expectations |
| non-renewable energy sources examples | oil, coal, natural gas, nuclear power |
| renewable energy sources examples | geothermal, hydroelectric, tidal, wave, wind, solar, biofuels |
| how coal is formed | dead plant material buried deep underground under layers of sediment which compresses it to form peat then with more compression lignite, then more compression to form coal. |
| how oil and natural gas are formed | small marine organisms die and get compressed beneath layers of sediments. The oil and gas formed over millions of years is held within porous sedimentary rock and trapped below a layer of impermeable rock. |
| how is most electricity generated | electromagnetic induction, where kinetic energy is transformed into electrical energy using a generator. The wire is rotated using a turbine, which is made to turn using an energy power source. This is typically done by passing steam or liquid through the turbine blades, causing a shaft connected to the generator to move, generating electricity. |
| how hydroelectric power generates electricity | Water flowing from a dam spins the blades of a turbine. The turbine is connected to a generator by a shaft, and as the shaft spins, it turns the generator to produce electricity. |
| how a thermal source for hydroelectric power generates electricity | A heat source heats water in a boiler to produce steam. The steam moves through turbine blades, causing them to spin. The turbine is connected to a shaft that turns copper coils in a generator, generating electricity. |
| how electricity is generated from a geothermal source | cold water is pumped into hot rocks, where it heats up and returns to the surface. This hot water heats a second water supply via a heat exchanger, producing steam that drives a turbine connected to a generator, generating electricity. The water is then recycled for continuous use. |
| how wind can be used to generate electricity | Addition of a gearbox maximizes the rotation of the shaft as it enters the generator. The brake will slow down or stop the rotor blade in very windy conditions to prevent the blade being damaged. |
| how solar power can be used to generate electricity | Solar energy uses photovoltaic cells to generate electricity. Although each cell produces a small amount of power, combining cells into panels and grouping panels into arrays can produce significant electricity. |
| how tidal power can be used to generate electricity | Tidal energy uses the natural rise and fall of water levels. As levels drop, water is held back by a tidal barrage (small dam that releases water back through a turbine) and then released through a turbine, generating electricity with a generator. The power generated depends on the tide level changes throughout the day. |
| how wave power is used to generate electricity | uses a turbine and generator to generate electricity but use smaller differences in water levels that are caused by wind action. Power is produced by channelling the energy of waves at sea instead of tides, may stop in calm weather |
| economic factors when deciding which power source to use | The supply of energy is expensive, and the demand is constantly increasing. If demand is high, price increases. This is why it is beneficial to use local supplies, meaning there is a lower transport price. |
| social factors when deciding which power source to use | depends on the local area. However, the energy business can cause displacement of people, due to flooding from hydroelectric power dams. This can change political relationships due to the supply and demand for oil from other countries |
| environmental factors when deciding which power source to use | Many renewable sources don’t produce CO2 emissions. Biofuels produce CO2 when combusted, but plant growth uses it in photosynthesis. Fossil fuels are a major contributor to CO2 emissions. Other impacts are pollution, changes to the ecosystem due to extraction of fossil fuels, and the visual impact. |
| advantages of fossil fuels | extraction provides jobs, plentiful supply in some locations |
| disadvantages of fossil fuels | limited supply, CO2 and toxic gases and released when burnt |
| advantages of nuclear power | power plants employ lots of people, doesnt produce CO2 |
| disadvantages of nuclear power | limited supply, risk of radiation leakage |
| advantages of biofuels | growing more plants uses CO2, doesnt produce CO2 |
| disadvantages of biofuels | a lot of land is needed to grow crops for fuel, CO2 and other toxic gases produced when burnt |
| advantages of geothermal power | doesnt produce CO2, water can be reused for other purposes |
| disadvantages of geothermal power | can be expensive to install, only some areas have suitable conditions |
| advantages of hydroelectric power | doesnt produce CO2, water can be reused for other purposes |
| disadvantages of hydroelectric power | building of dams impacts the natural flow of water, villages and ecosystems could be destroyed when dams or reservoirs are built |
| advantages of tidal power | doesnt produce CO2, tidal movements not dependent on weather conditions |
| disadvantages of tidal power | limited to specific costal areas, impacts the tourist industry and local fishers |
| advantages of wave power | doesnt produce CO2, is renewable |
| disadvantages of wave power | limited to specific areas, currently not very efficient so lots of resources are needed |
| advantages of solar power | doesnt produce CO2, sunlight is not a limited resource |
| disadvantages of solar power | only efficient under certain weather conditions, generation only occurs in daylight hours |
| advantages of wind power | doesnt produce CO2, uses a renewable resource |
| disadvantages of wind power | uses a large area, not all locations are suitable |
| industrial impact on the demand for energy | In traditional farming communities, energy usage is lower than in industrialized areas. Advanced technology made goods more affordable and transitioning them from luxuries to necessities. With increased demand for these goods, energy needs for production also rise. |
| domestic impact on the demand for energy | Affordable goods, such as TVs, drive domestic demand influenced by social standards. Increased purchases raise energy consumption. However, buying out-of-season fruits and vegetables leads to waste. Meeting demand, whether through local production or transportation, entails significant energy costs. |
| transport impact on the demand for energy | The drive for development of efficient productions means that many manufacturers are supplying customers across the globe. This can decrease production costs but increases transportation costs like shipping and air transport which use lots of fossil fuels. Transporting is cheaper so businesses still do it, but is used more is used rather than producing locally. |
| economic impact on the demand for energy | Domestic demand and purchase of goods depends on people. If the economy is good, there will be higher employment and therefor more money for people to spend. If economy is poor, it means less manufacturing (less energy used), fewer goods to transport (less energy used), inability to purchase foreign energy supplies. A reduction of manufacturing in one country can have effects on global economy. |
| climate impact on the demand for energy | Comparing energy usage between countries is complex due to varying weather conditions. Temperate climates with colder winters experience higher heating demands. Winter months see increased electric lighting usage due to shorter daylight hours. Climate change has intensified weather extremes, driving up energy consumption, particularly in urban areas where additional heating or air conditioning is necessary. |
| how to reduce energy consumption (using insulation, double or triple glazing) | Using more efficient equipment reduces energy consumption. Insulation, particularly in colder countries, minimizes heat loss, cutting down on energy usage. Prioritizing insulation in the loft and walls is effective. While reducing window size can limit heat loss, double glazing balances this with increased lighting energy use. |
| how to use other ways to reduce energy consumption | Turn off unused electrical devices. Energy-efficient models should be prioritized. Appliances use energy directly as fuel or via electricity. Using newer, more efficient versions can save energy. |
| how energy from waste reduces energy consumption | Anaerobic digestion breaks down organic waste into methane for heating and improves soil. Household waste can be burned for heat and electricity generation, but emits harmful gases. Used cooking oils can be recycled into biofuels for vehicles via collection schemes in many countries. |
| how education reduces energy consumption | New technologies and designs need effective promotion to make an impact. Investing in new equipment for homes or factories can be costlier than traditional methods. Research indicates people prioritize environmental concerns but are hesitant to pay extra. Education should emphasize significant energy bill savings despite higher initial costs. |
| how exploiting existing energy resources reduces energy consumption | Cost is the primary factor in selecting energy sources. Some countries import fuel due to high extraction costs. Power companies aim for uninterrupted supply despite challenges. Wind turbines and fossil fuel stations are used together to provide consistent energy, reducing fossil fuel use |
| how transport policies reduce energy consumption | Manufacturing, global transportation, and personal vehicles consume significant energy. Governments regulate transportation efficiency through measures like fuel taxation, vehicle restrictions, and car-sharing incentives. |
| fracking | Process of obtaining oil or gas from shale rock by the breaking open to rocks using water, sand and chemicals. |
| what is fracking and how it is achieved | Hydraulic fracking involves blasting large amounts of water, sand and chemicals deep underground to extract oil and natural gas. To obtain these resources, a vertical hole, often 2-3km deep, is drilled to reach the fuel-rich rocks (shale rocks). |
| advantages for fracking | supply many jobs locally, allows more access to gas and oil which are limited, reduces the need to import oil or gas from other countries |
| disadvantages for fracking | noise pollution, uses lots of water which reduces availability for other uses, there is a risk of toxins and may affect local residents |
| causes for marine oil spills | offshore oil extraction with leakage from rigs, oil pipelines with leaks in the pipework moving the oil to storage, shipping and transporting the oil with the risk of collision or damage to the oil tankers |
| what ecosystems are impacted by oil spills | birds, marine mammals, coral reefs, beaches |
| how phytoplankton are impacted by oil spills | oil stays on the surface of the water and prevents light from entering. This prevents the phytoplankton from photosynthesizing so they die |
| how fish are impacted by oil spills | shortage of food due to reduction in phytoplankton, oil floating on the surface prevents gas exchange and they become short of oxygen and die. The oil affects their gills by direct contact |
| how birds are impacted by oil spills | shortage of food as fish and other creates die. may consume oil when eating fish which can be toxic. When hunting for food feathers become covered in oil making them unable to fly |
| how mammals are impacted by oil spills | food sources are reduced, may swallow oil while feeding which is toxic. A layer of oil will affect their skin |
| how reefs are impacted by oil spills | prevents sunlight from reaching plants and phytoplankton preventing photosynthesis, lack of oxygen will cause other species to die, areas of reef may become covered in oil |
| how beaches are impacted by oil spills | oil is often washed in by the tides coating rocks, organisms living in shallow water and rock pools may be killed by the toxic affects of the oil. Animal food sources will be affected |
| how MARPOL reduces oil spills | The IMO oversees shipping safety and established the MARPOL treaty to address ship pollution. It regulates waste disposal and oil transfers at sea, replacing ocean dumping practices. Tankers must be certified for compliance, facing fines or port restrictions for non-compliance |
| how tanker design reduces oil spills | Regulations ensure safe transportation of hazardous substances. Oil spreads more extensively at sea than on land, often due to hull damage. Modern tankers feature increased hull compartments and double hulls, reducing spillage risks despite higher construction costs. While not eliminating spills entirely, double-hulled tankers have significantly reduced incidents. |
| how floating booms reduces oil spills | Booms are floating barriers used to contain oil spills, especially effective in small, calm areas. They protect sensitive environments like river estuaries during spill response. However, they are less effective in rough, stormy seas, which can cause vessel damage. |
| how detergent sprays reduces oil spills | Detergents break down oil slicks into smaller droplets, aiding dispersion and degradation over time. They're most effective for smaller spills, but recent research indicates potential environmental harm, especially for coral reefs with low detergent tolerance. |
| how skimmers reduce oil spills | Skimmers collect oil from water surfaces without altering the oil's properties. They use materials that oil adheres to, dragging it off the surface for collection in containers. Skimmers are effective within contained oil slicks, but they are less efficient in rough or stormy sea conditions. |
| Ecosystem | All the living things (biotic components) together with all the non-living things (abiotic components) in an area |
| Population | All the organisms of one species living in a defined area |
| Community | A group of populations of different species that live together in an area and interact with each other |
| Habitat | The place within an ecosystem where an organism lives |
| biotic | Living components of the environment that may affect other living things |
| biotic components examples | producers, primary, secondary, tertiary consumers, decomposers, herbivore, carnivore, omnivore |
| abiotic | Non-living components of the environment that may affect other living things |
| abiotic components | temperature, humidity, water, oxygen, salinity, light, pH |
| role of chlorophyll | absorb sunlight used for photosynthesis |
| word equation for photosynthesis | glucose + oxygen → carbon dioxide + water |
| energy flows in ecosystem | decreases because 90% is lost as it is used for cellular activity, movement, growing, respiration, and lost via excretion and defecation and as heat, so that only 10% is transferred/passed on to the next trophic level |
| word equation for respiration | carbon dioxide + water → glucose + oxygen |
| causes of habitat loss | drainage of wetlands, intensive agriculture practices, deforestation, urbanisation |
| impacts of habitat loss | extinction, loss of bio diversity, genetic depletion |
| genetic depletion | The loss of species containing potentially useful genes |
| biodiversity | the variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable |
| causes of deforestation | land needed for farming, building dams and mining activities, urbanisation |
| impacts of deforestation | habitat loss, soil erosion, climate change, loss of biodiversity and genetic depletion |
| causes of soil erosion | deforestation, over cultivation of crop land damaging the soil, overgrazing by livestock (cattle, sheep, goats) |
| impact of soil erosion | sedimentation of waterways (silting), infertile soils, desertification, crop failure, displacement of people, food shortages |
| role of forests within the water cycle | Forests add water to the atmosphere in the process of respiration. This leads to the formation of clouds. Eventually the clouds release the water back as precipitation |
| role of forests with carbon sinks and carbon stores | growing forests act as carbon captures (fixing carbon from atmospheric CO2 into glucose in plants by the process of photosynthesis) and carbon sinks and mature forests act as carbon storage locked away long term in the plant cells, cellulose, other organic substances, and in tree trunks |
| why we need forests | medicine, raw materials - building and furniture, CO2 capture and storage |
| 4 components of soil | mineral particles, organic content, air, water |
| mineral ions | nitrogen as nitrate ions (NO3-), phosphorus as phosphate ions (PO43-), potassium as potassium ions (K+) |
| arable farming | the production of plants for human consumption. For example, growing of rice, maize, wheat, and soy beans |
| pastoral farming | the production of animals or animal-related substances |
| mixed farming | those practises, both rearing livestock and growing crops |
| subsistence farming | the cultivation and production of food to meet the needs of the farmers and their families. There is very surplus food; if there is any, it is often exchanged for other things the family needs |
| commercial farming | the cultivation of products with the main focus of selling them for cash |
| techniques used to increase agricultural yields | rotation, fertilisers, irrigation, insect control (insecticide and biological control), weed control (herbicide), fungi control (fungicide), mechanisation, selective breeding, genetic modification, controlled environments: greenhouses and hydroponics |
| what is crop rotation | growing different types of plants in different plots each year, related groups of plants are grown together during a season |
| advantages of crop rotation | diseases in the soil affecting that plant are left behind and have nothing to infect, pests need to find the new site and so their numbers are reduced, the soil in the new plot is more likely to have the nutrients the crop needs |
| disadvantages of crop rotation | it’s not as efficient as intensive farming |
| fertilisers | contain minerals such as nitrogen, potassium and phosphorus, which are essential for healthy plant growth |
| advantages of organic fertilisers | uses natural resources, bulky types also supply organic matter to improve the soil |
| disadvantages of organic fertilisers | can be unpleasant to handle, bulky types are harder to transport |
| advantages of inorganic fertilisers | can be manufactures to meet a specific need, can be easier to store |
| disadvantages of inorganic fertilisers | cost of manufacture, transport costs |
| why is water important for plants | a large percent of a plant is made up of water, water is essential for cell activity and used in photosynthesis, mineral nutrient uptake by the roots require water in the soil |
| types of irrigation | overhead irrigation, clay pot irrigation, trickle drip irrigation system, flood irrigation method |
| advantages of overhead irrigation | relatively easy to set up, can cover a large area of land from one |
| disadvantages of overhead irrigation | not very precise, small droplets easily blown by wind, so not all plants may be irrigated |
| clay pot irrigation | uses buried, porous clay pots filled with water to provide controlled irrigation to plants |
| advantages of clay pot irrigation | simple technology so little can go wrong, easy to check the amount of water provided to the soil |
| disadvantages of clay pot irrigation | only suitable for larger more permanent plants, large labour costs |
| trickle drip irrigation system | placing tubes around the soil of the plants and letting water drip into the roots slowly |
| advantages of trickle drip irrigation system | water is placed directly at the base of the plant, water is used efficiently |
| disadvantages of trickle drip irrigation system | expensive to install and can be complex to maintain, cannot easily be moved |
| flood irrigation method | water is delivered to the field by a soil channel or pipe and allowed to flow freely over the ground throughout the crop, to be effective fields need barriers high enough to stop water run off |
| advantages of flood irrigation method | inexpensive, can cover large areas quickly |
| disadvantages of flood irrigation method | inefficient use of water, damages soil structure |
| pest | is an animal that attacks or feeds upon the crop plant |
| pesticide | a chemical used to control a pest |
| insecticide | a chemical used to control insects |
| why weeds need to be controlled | compete with crops for water light and nutrients, make cultivation difficult, can look untidy |
| herbicides uses | they can be used to completely clear uncultivated areas of all previous vegetation, or used to selectively kill weeds growing among a crop, they are chemicals used to control weeds |
| what do fungi do to a crop | they cause fungal diseases in the plants |
