Flashcards
Unit 1B
Cards in this deck (58)
- 1What is an ecosystem?An ecosystem is a unit that includes all biotic parts and abiotic parts in an area.
- 2What is the name and function of each part of an ecosystem?Producer - uses sunlight energy to produce food.
Consumer - gains energy by eating other organisms (producers & other consumers).
Decomposer (bacteria and fungi) - gains energy by breaking down dead material (dead producers, consumers or leaves). - 3Give an example food chain for a pond?Algae --> tadpole --> dragonfly nymph --> frog --> heron.
- 4Give an example of how a change in one part of an ecosystem has an impact on other parts?Hot, dry summer --> reduced plant growth --> fewer berries for birds in the winter --> number of sparrows and thrushes fall --> fewer birds for sparrowhawks to hunt, so the number of sparrowhawks fall.
- 5Give an example of how a change in one part of an ecosystem has an impact on other parts?Hedgerow trimmed --> fewer habitats for ladybirds, greenfly and spiders, so numbers fall --> sparrows and thrushes have less to eat so numbers fall --> fewer birds for sparrowhawks to hunt so the number of sparrowhawks falls.
- 6What is eutrophication?Fertilisers washed into rivers. The nitrates increase the growth of algae which decreases oxygen supplies and fish can die.
- 7Describe the distribution of tropical rainforests, polar/tundra and hot deserts?Tropical rainforest - found around the equator, between the tropics as it is hot and wet all year.
Polar/Tundra - found at the north and south poles/above 60degrees, very cold summers are brief.
Hot desert - found between 15deg and 35deg, little rainfall, very hot in the day but cold in the night. - 8Describe the climate of a tropical rainforest?The climate is the same all year round (no definite seasons). It's hot (20-28oC) as it's near the equator so the sun is overhead all year round. Rainfall is very high, around 2000mm/year.
- 9Describe the soil of a tropical rainforest?The soil isn't very fertile as heavy rain washes nutrients away. There are nutrients at the surface due fallen decayed leaves, but it is a thin layer as decay occurs fast in the warm, moist conditions.
- 10Describe the plants in tropical rainforests?Most trees are evergreen (don't drop leaves in a particular season). Many trees are very tall and the vegetation cover is dense (very little light reaches the forest floor). There are lots of plants that grow on other plants (epiphytes- ferns and orchids).
- 11Describe the animals in tropical rainforests?Rainforests are believed to contain more animal species than any other ecosystem. Gorillas, jaguars, anacondas, tree frogs and sloths. Also many insects and birds.
- 12Describe the people in tropical rainforests?People have adapted to sustainably live in the rainforest.
- 13Give an example of how rainforests are interdependent?1. warm and wet climate means dead plant matter is decomposed quickly, making surface soil high in nutrients, so plants can grow quickly and easily.
2. Plants pass on their nutrients when they are eaten by animals, the dense vegetation provides lots of food so plant populations are high.
3. changes to the rainforest ecosystem (e.g. people reducing tree cover by deforestation), can have knock-on effects on the whole ecosystem, e.g. by reducing the amount of CO2 being absorbed, adds to the greenhouse effect and changing the climate.
4. trees also intercept an take up lots of water, and release it back into the atmosphere, providing water for rainfall. Deforestation means the climate may change, the risk of drought increases. - 14How do rainforests have very high biodiversity?Biodiversity is the variety of organisms living in a particular area. Rainforests contain around 50% of the world's plant, animal and insect species. This is because plants and animals don't have to cope with changing conditions and there is always plenty to eat. Deforestation and uncontrolled development of the rainforest are likely to lead to the extinction of many species and the loss of biodiversity.
- 15Give 4 examples of how rainforest plants have adapted to the physical conditions?1. tall trees competing for sunlight have big roots (buttress roots) to support their trunks.
2. plants have thick, waxy leaves with pointed tips (drip tips) to channel the water to a point so it runs off and the weight doesn't damage the plant or bacteria growth in standing water.
3. many trees have smooth, thin bark as there is no need to protect the trunk from cold temperatures, also allows water to run off easily.
4. climbing plants (lianas) use tree trunks to climb up to the sunlight. - 16Give 4 examples of how rainforest animals have adapted to the physical conditions?1. many animals spend their entire lives high up in the canopy, so have strong limbs for climbing etc (howler monkeys).
2. some birds have short, pointy wings so that they can easily manoeuvre between the dense tangle of branches in the trees, e.g. the harpy eagle.
3. some animals are camouflaged (leaf-tailed geckos) can hide from predators.
4. many animals are nocturnal (sloths) so feed at night when it's cooler, helping them save energy. - 17What are the six reasons for the deforestation of rainforests?Population pressure - as population increases, more trees need to be cleared.
Mineral extraction - minerals (gold/iron) are mined and sold to make money.
Energy development - building dams to generate hydro-electric power floods large areas of forest.
Commercial logging - trees felled for money, roads needed as well.
Commercial farming - the forest is cleared to make space for cattle grazing, palm oil/soya plantations.
Subsistence farming - forest cleared so farmers can grow food for themselves and their families. - 18Name three environmental impacts of deforestation?1. no trees hold the soil so rain washes it away, leads to landslides and flooding.
2. no tree canopy to intercept rainfall and tree roots to absorb it, more water reaches the soil, reducing fertility as nutrients washed away from plants.
3. trees remove CO2 from the atmosphere, also burning vegetation produces CO2, all of which adds to the greenhouse effect. (deforestation is accountable for 15% of global CO2 emissions per year). - 19Name for economic impacts of deforestation?1. logging, farming and mining create jobs.
2. lots of money is made from selling these products.
3. in the long term, deforestation can destroy the resources that countries depend on, e.g. timber, and reduce the attractiveness of the area to tourists.
4. the livelihoods of some local people are destroyed, loss of animals and plants which they rely on to make a living. - 20How is the rate of deforestation changing?It's very high - about 130,000 km^2 per year. Overall it's decreasing but in places like Borneo and Nigeria it's increasing. Brazil has decreased its deforestation rate since 1990.
- 21How much land does the Amazon rainforest cover?8million km^2 however since 1978 over 750,000 km^2 has been destroyed by deforestation. Causes are:
65-70% - commercial ranching
20-25% - small-scale subsistence farming
5-10% - commercial farming (soy etc)
2-3% - logging and illegal logging
1-2% - mineral extraction (gold), road building, energy development and new settlements.
Also, population growth is putting pressure on it and farmers need more land as it quickly becomes infertile. - 22Name two environmental impacts of deforestation in the Amazon?1. the Amazon stores about 100billion tonnes of carbon, some is released in deforestation, causing global warming.
2. Brazil is losing 55 million tonnes of topsoil every year due to soil erosion caused by soy farming. - 23Name five economic impacts of deforestation in the Amazon?1. economic development has brought wealth to countries that were very poor.
2. farming makes a lot of money for countries in the rainforest, e.g. Brazil made $6.9billion from trading cattle.
3. the mining industry creates jobs for loads of people, e.g. the Buenaventura mining company in Peru employs over 3100 people.
4. logging contributes a huge amount to Brazil's economy.
5. local Brazilian rubber tapper who extract natural rubber from rubber trees have lost their livelihoods as trees have been cut down. - 24What are the five main benefits of protecting the rainforest?1. to preserve its biodiversity.
2. products such as rubber, coffee, chocolate, medicines.
3. long-term economic benefits, e.g. ecotourism.
4. reduce the greenhouse effect which will affect all countries not just the ones in the rainforest.
5. they help regulate the climate and weather cycle, without them the risk of drought/flooding would increase in certain areas. - 25What is selective logging?Only some trees (older or inferior) are felled, most are left. This is less damaging as forest still remains and soil isn't exposed so it can regenerate in the future. Least damaging forms are horse logging or helicopter logging (Malaysia state of Sarawak).
- 26What is replanting?Where new trees are planted to replace the ones that are cut down, means there will be trees for people to use in the future. The same type of tree must be planted so there is still a variety of trees. Some countries are making laws to make logging companies replant trees when they clear an area.
- 27What is ecotourism?Tourism that minimises damage to the environment and benefits the local people. Only a small number of people are allowed into an area at a time and precautions are taken, e.g. waste and litter are disposed of properly to prevent land and water contamination. Provides jobs for the locals, raises awareness of conservation issues and brings money for conservation. More people employed in tourism means fewer people cutting down trees. This has worked well in Costa Rica, ecotourism is the largest source of income and has led to 21% of the country being protected from development.
- 28What are the international hardwood agreements?Hardwood is a term for certain tree species, e.g. teak and mahogany (used to make furniture). It's in high demand from rich countries, meaning some tropical trees are becoming rarer. There are international agreements to reduce illegal logging and promote hardwood from sustainably managed forests. E.g. the forest stewardship council is an organisation made up of non-government organisations which makes sustainably-sourced timber with their logo so consumers choose their products.
- 29How is education a sustainable management of deforestation?Education of the international community about the impacts of deforestation can encourage people to buy products that are certified from sustainably managed sources. Educating local people about the impacts of deforestation and ways to reduce the impacts decreases damage to the environment. Also educating the locals about alternative ways to make money that don't damage the environment as much such as ecotourism.
- 30What is reducing debt?A lot of tropical rainforests are in LICs which often borrow money from wealthier countries or organizations to fund development or cope with emergencies. This money has to be paid back with interest but the countries often allow logging, farming and mining in rainforests to do so. Reducing debt means countries don't have to do this and the rainforests can be conserved for the future. Debt can be cancelled by countries/organisations but there is no guarantee the money will be spent on conservation instead. A better solution is a conservation swap, where part of a country's debt is paid in exchange for a guarantee that the money is spent on conservation. E.g. in 2008 the USA reduced Peru's debt by $25million in exchange for rainforest conservation.
- 31What is conservation?Many countries have set up national parks and nature reserves within rainforests. In these areas damaging activities (logging) are restricted but a lack of funds can make it difficult to police the restrictions. As a result, some countries have set up funds which overseas governments and businesses can invest in. The countries get the money in exchange for rainforest conservation. Money can be used to enforce restrictions on damaging activities and to promote sustainable use of the rainforests, e.g. Norway has paid $1 billion into Brazil's Amazon fund to be used for conservation.
- 32Describe the climate of a hot desert?There is little rainfall (>250mm/year) and it's timing varies a lot. Temperatures are very extreme, hot in day (45oC) to cold at night (5oC).
- 33Describe the soil in a hot desert?It's usually shallow with a coarse, gravelly texture. Hardly any leaf fall so the soil isn't very fertile. Lack of rainfall and plant material, means the soil is often dry.
- 34Describe the plants in a hot desert?Plant growth is very sparse due to the lack of rainfall (cacti and thornbushes). Plants usually quite short (low shrubs and short woody trees) though cacti can grow fairly tall. Many plants have a short life cycle.
- 35Describe the animals in hot deserts?Animals are adapted to the harsh environment, e.g. lizards, snakes, insects and scorpions. Mammals tend to be small and nocturnal e.g. kangaroo rats. Most birds leave the desert during the harshest conditions but some, e.g. roadrunners, can live there all year round.
- 36Describe the people in hot deserts?Many people living in deserts grow a few crops where there are natural springs or wells to supply water, usually in the desert fringes. Indigenous people are often nomadic, travel all the time in search of food and water for their herds (goats and sheep).
- 37Explain how hot deserts are fragile, interdependent ecosystems?1. plants gain nutrients from soil and provide nutrients and water to animals that eat them. Then, the animals spread seeds through their dung, helping the plant reproduce.
2. the hot and dry climate affects the soil in the deserts, they are salty due to high evaporation and relatively low in nutrients because there is little decomposition of dead plant matter, meaning plants struggle to grow.
3. the sparse vegetation limits the amount of food available, so the desert can only support low-density populations of animals.
4. water supplies in deserts can be extremely scarce as rainfall is very low, coarse desert soil means rain is quickly drained away. Animals and people have to find ways to cope, e.g. constantly moving.
5. people have to irrigate to grow crops, meaning they draw unsustainable amounts of water from wells lowering the levels of water underground. This causes plants/animals that depend on this water to be affected.
6. changes to components of the ecosystem, such as allowing cattle to overgraze vegetation, can have knock-on effects on the whole ecosystem (soil erosion). - 38Explain how biodiversity is high in areas with water?Hot deserts have relatively low biodiversity (compared with tropical rainforests). Ephemeral (temporary) areas like ponds or rivers or along the desert margins have the highest levels of biodiversity and contain a high proportion of species that are endemic (unique) to the desert. Areas with water also have a high density of human populations. Low biodiversity and pressure from development and climate change mean that deserts contain many biodiversity hotspots.
- 39How is human development affecting biodiversity?Human development threatens biodiversity by increasing desertification and by over-using or contaminating water supplies. Also, development around the desert margins means that habitats are being divided up by roads, threatening animals that migrate over large distances to find food and water, e.g. desert bighorn sheep.
- 40How does global warming affect biodiversity?Global warming is generally making hot deserts hotter and drier. This is forcing some species (lizards) to move to cooler areas to cope with rising temperature. However, species that are already at the limits of their environment don't have anywhere to go, so are at risk of decline or extinction.
- 41Name 4 desert plant adaptations?1. plant roots are either extremely long to reach very deep water supplies or very spread out near the surface to catch as much water as possible when it rains.
2. many plants (cacti) are succulents. They have large fleshy stems for storing water and thick waxy skin to reduce water loss. Some also have sharp spines and toxins to stop animals from stealing water from their stems.
3. some plants have small leaves/spines - low surface area to reduce transpiration.
4. the seeds of some plants only germinate when it rains - the plants grow, flower and release seeds in just a few weeks, which makes sure they only grow when there's enough water to survive. - 42Name 5 desert animal adaptations?1. being nocturnal means that animals can stay cool during the day, when it's hottest. Desert animals also often have long limbs/ears, providing a large surface area to lose heat from.
2. lizards and snakes are able to tolerate high body temperatures e.g. desert iguanas can survive temperatures up to 42oC.
3. some bigger animals store large amounts of fat which they can break down into the water when needed, e.g. camels' humps.
4. some animals get all the water they need from what they eat, e.g. cactus mice, most desert animals minimise water loss from sweat and urine.
5. long eyelashes/triple eyelids/nostril closing are adaptations to cope with sand. They also have large, flat feet so that they don't sink into the sand. - 43What opportunities has mineral extraction created in the western desert, USA?Western desert is rich in copper, uranium, lead, zinc and coal. Opencast mining is carried out on a large scale providing economic income and jobs.
- 44What opportunities has energy created in the western desert, USA?1. strong insolation in desert = opportunity for solar power plants, e.g. the Sonoran solar project in Arizona will produce energy for 100,000 homes and provide jobs 360 workers.
2. hydroelectric power (HEP) plants supply western desert communities with electricity, powered by water leaving lake mead, employed 5,000 people.
3. fossil fuels - been drilling since 1905, Navajo people own 25 sites, employs 100 and produces $50mill of oil. - 45What opportunities has farming created in the western desert, USA?high temps and lots of sunlight is favourable to agriculture, but water is needed, two ways are:
1. aquifers - large stores of water lie beneath some hot desert regions. If permeable rock sits on impermeable, rainwater and groundwater seep into the permeable layer and are trapped. Wells can be used to access this water and to grow lush crops of vegetables, lemons, peppers and grapes.
2. canals - most canals are used for large-scale industrialised agriculture, farmers are allocated 80% of colarado water, even though they make up 10% of the economy. - 46What opportunities has tourism created in the western desert, USA?Tourism is the western desert's most important source of income:
1. national parks, e.g. Grand Canyon and Joshua tree park.
2. heritage and culture, e.g. native Americans are celebrated at the Colorado museum in Arizona.
3. entertainment, e.g. Las Vegas 37million visitors per year.
4. watersports - two main lakes attract millions of visitors every year. - 47What can people do to cope with the extreme temperatures in the western desert, USA?- natives lived in earth houses, with wooden frames packed with clay and thatched with grass = keeps houses cool in the day and warm at night.
- nineteenth/ twentieth-century migrants made houses with flat roofs to collect rainwater, small houses to reduce sunlight and keep temps low, whitewashed walls to reflect sunlight and keep buildings cool.
- recently sports pitches replaced with fake grass.
- adapting gardens to drought-resistant landscapes rather than irrigating lawns (xeriscaping). - 48What can people do to handle the water supply in the western desert, USA? (in the past)Until now, cities in the western desert have prospered due to masses of water being transported from the river Colorado for farming and tourism. The river brought meltwater in the summer but had low flow from September to April.
The Hoover dam was built in 1935, which stores two years worth of water in lake mead. Then the Glen canyon dam followed in 1963. - 49What can people do to handle the water supply in the western desert, USA? (in the future)- 30million people in SW USA depend on Colorado.
- Phoenix takes the maximum share of water it is allowed, but is predicted to double its population by 2050.
- between 2000 and 2010, several states experienced rapid population growth, more than double the national average. Nevada (35%), Arizona (25%) and Utah (24%).
-There is a political limit, an international agreement states water must be allowed to flow into Mexico.
-Whilst these cities continue to grow there is a physical limit on how much water can be taken from the Colorado.
-Water security is threatened by climate change, reduced rainfall could occur when water is already scarce, e.g. in 2014, Lake Mead reached record lows. - 50What can people do to cope with the inaccessibility in the western desert, USA?The low population density (<1 per sqkm) means parts of the western desert lack surfaced roads so accessibility is limited. Tourists must find their own way so it can be very dangerous if your car breaks down, e.g. in 2015 a tourist died of dehydration.
- late 1800s, rail developed as they decided water-rich Las Vegas valley would be a perfect location for a train station leading to now.
- better roads were laid in the 1900s so people travelled through the desert in cars and buses.
- major cities can now be reached directly by air, e.g. Las Vegas airport receives over 40million people annually. - 51What is desertification?Desertification is the degradation of land so that it becomes more desert-like (drier & less productive). A third of the world's land surface is at risk of desertification, particularly at the desert margins. Soil erosion is a key part of desertification.
- 52What is soil erosion?Soil erosion is where soil that is exposed is easily removed by wind or water. Nutrients in the soil (e.g. from fallen leaves/dead plants) are lost, making soil unproductive. Eventually, the ground becomes sandy, dusty, stony or just bare rock.
- 53How does climate change cause desertification?1. rainfall - climate change is expected to reduce rainfall in areas that are already quite dry. Less rain means less water for plant growth so they die. Plants hold the soil together so if they die then the soil is easily eroded.
2. temperatures - global temperatures are expected to increase. Higher temps mean that more water evaporates from the land and from plants. Makes soil drier and plants die (soil erosion). - 54How do human activities cause desertification?1. removal of fuelwood - many people in arid (dry) areas need wood for cooking, removal of trees leads to soil erosion.
2. overgrazing - too many cattle/sheep eat the plants faster than they regrow leading to soil erosion, also trampling adds to this.
3. over-cultivation - if crops are planted in the same area continually, all the nutrients in the soil get used up this means that plants can no longer be grown leading to soil erosion.
4. population growth - puts pressure on the land, leading to more deforestation (for firewood), more overgrazing and more over-cultivation. - 55How does water management reduce the risk of desertification?growing crops that don't need much water (millet, sorghum or olives) can reduce water use. Using drip irrigation on crops instead of surface irrigation means that the soil isn't eroded by lots of water being added in one go.
- 56How does tree planting reduce the risk of desertification?trees can be planted to act as windbreaks to protect soil from wind erosion, trees also stabilise the sand to prevent desert from encroaching on farmland. Also growing trees amongst crops an protect them and provide shade which will reduce evaporation rates.
- 57How does soil management reduce the risk of desertification?leaving areas of land to rest in between grazing/planting lets them recover their nutrients. Rotating crops that use different nutrients from the soil means the same nutrients aren't always removed, compost can add extra nutrients to the soil.
- 58How does the use of appropriate technology reduce the risk of desertification?involve using cheap, sustainable and easily available materials that are easy for the locals to maintain, e.g. sand fences (to trap windblown sand) or terraces (to stabilise the soil). The rate of deforestation can be reduced by using solar cookers which use the suns energy to heat food, they're cheap and easy to make and don't require fuelwood to work.
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- Year 11 Geography Flashcards on Unit 1B, created by finn squires on 04/04/2018.
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