Paper 1: The living world Flashcards
1
Q
What is an ecosystem?
A
An ecosystem is an area that includes all the biotic (living organisms) parts such as plants and animals and the abiotic (non-living) such as soil, rocks and climate sharing an environment.
2
Q
Identify three biotic elements of an ecosystem.
A
Any three living organisms.
3
Q
Identify three abiotic elements of an ecosystem.
A
Soil, rock and climate.
4
Q
What is a producer?
A
A producer is an organism that produces its own food, usually by photosynthesis such as trees.
5
Q
What is the difference between a primary and secondary consumer?
A
A primary consumer is a herbivore that consumes producers. Secondary consumers are carnivores that consume primary producers.
6
Q
What is a carnivore?
A
A carnivore is a consumer of herbivores (animals).
7
Q
What is a herbivore?
A
A herbivore is a consumer of primary producers (plants).
8
Q
What is an omnivore?
A
An omnivore consumes both producers (plants) and animals.
9
Q
What is a decomposer?
A
A decomposer is an organism that decomposes and breaks down dead plants and animals.
10
Q
Identify one example of a decomposer in an ecosystem
A
Bacteria or fungi.
11
Q
Why are decomposers so important for ecosystems?
A
If they were not in the ecosystem, plants would not get essential nutrients and dead matter would gather.
12
Q
Why is photosynthesis so important in ecosystems?
A
Without photosynthesis there would be no primary consumers which would lead to the break-down of ecosystems as primary consumers would have no source of energy. Likewise, there would be no food for secondary consumers.
13
Q
What is a food chain?
A
A food chain shows the flow of energy from producer to tertiary consumer.
14
Q
What is a food web?
A
A food web shows a collection of food chains.
15
Q
What is the nutrient cycle?
A
The nutrient cycle shows the transfer of nutrients through an ecosystem.
16
Q
Give an example of a small-scale ecosystem.
A
Pond, hedgerow or woods (or any other small scale ecosystem)
17
Q
Identify a small-scale ecosystem you have studied.
A
Moseley Bog
18
Q
Explain how the removal of a primary producer can have an impact on an ecosystem.
A
The removal of a primary producer can lead to the collapse of an ecosystem. By removing a primary producer, the food source of primary consumers is also removed which can lead to these organisms dying. In turn this removes the food source of secondary consumers leading to large scale devastation across the ecosystem.
19
Q
What is a biome?
A
Large ecological areas on the surface of earth with plants and animals adapting to their environment
20
Q
Identify three of the major biomes.
A
Any from tropical rainforest, hot desert, taiga, savannah, polar, deciduous forest etc.
21
Q
Describe the distribution of the tropical rainforest biome.
A
Between 10 degrees North and 10 degrees South of the Equator where temperatures stay near 28 degrees Celcius throughout the year. Rainforests typically receive over 2000mm of rain each year. The largest rainforests are in the Amazon in Brazil (South America), Demographic Republic of Congo (Africa) and Indonesia (South East Asia). Tropical rainforests are also found in Hawaii and the islands of the Pacific and Caribbean.
22
Q
Explain the distribution of the tropical rainforest biome.
A
Tropical rainforests are found near the equator. Most tropical rainforests fall between the Tropic of Cancer and the Tropic of Capricorn. These areas receive more sunlight.. The high temperatures means that evaporation happens at a fast rate, resulting in frequent rainfall. Also, air is rising due to the Hadley cell resulting in convectional rainfall.
23
Q
Identify the main layers of found in the tropical rainforest ecosystem.
A
Emergent, canopy, under canopy, shrub and ground layer.
24
Q
Describe the characteristics of the emergent layer.
A
The tallest trees which are usually over 50m tall.
25
Describe the characteristics of the canopy layer.
The sea of leaves blocking out the sun from the lower layers is called the canopy. It contains over 50 percent of the rainforest wildlife including birds, snakes and monkeys.
26
Describe the characteristics of the under canopy layer.
The under canopy mainly contains bare tree trunks and lianas. Lianas are vines that climb the vegetation in a bid to reach sunlight.
27
Describe the characteristics of the shrub layer.
The shrub layer has the densest plant growth. It contains shrubs and ferns and other plants needing less light. Saplings of emergent and canopy trees can also be found here.
28
Describe the characteristics of the forest floor.
The forest floor is usually dark and damp. It contains a layer of rotting leaves and dead animals called litter. This decomposes rapidly (within 6 weeks) to form a thin humus, rich in nutrients. Below the rich top soil, the soil lacks nutrients. This is because nutrients are rapidly absorbed by vegetation.
29
Describe the typical climate of a tropical rainforest ecosystem.
Very wet with over 2,000 mm of rainfall per year, very warm with an average daily temperature of 28 degrees Celcius. The temperature never drops below 20 degrees Celcius and rarely exceeds 35 degrees Celcius. The atmosphere is hot and humid. The climate is consistent all year round. There are no seasons.
30
Describe three characteristics of soil in the tropical rainforest ecosystem.
Most 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.
31
Why does the tropical rainforest have the greatest biodiversity of all ecosystems?
The 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, e.g. trees and plants have shallow-reaching roots to absorb nutrients from the thin fertile layer in the soil.
32
Identify 4 interdependent features of the tropical rainforest
Climate, water, soils, plants, animals and people.
33
Identify 3 ways vegetation has adapted to the rainforest environment.
Emergents, Drip tips, Waxy leaves, Epiphytes, Wide buttress roots
34
Explain 3 ways vegetation has adapted to the rainforest environment.
Most trees in the rainforest have wide buttress roots which support them as they grow incredibly tall to reach sunlight. Roots grow wide rather than deep because nutrients are found in the top layer of soil. Lianas (vines) grow around trees as they climb to reach sunlight. Leaves have pointed drip-tips which cause water to run off – so the weight of the water doesn’t damage the plant.
35
Identify 3 ways animals have adapted to the rainforest environment.
Prehensile tail, Bright colour, Nocturnal, Sharp claws, Sticky foot pads, Camouflage
36
Explain 3 ways animals has adapted to the rainforest environment.
Sloths: Move slowly so predators don't spot them. Also camouflaged by letting green moss grow in their fur. Curved feet help them grip tree branches. Spider monkey: The prehensile tail acts as an extra limb, allowing the spider monkey to be able to grasp the branches of trees.
37
How has the rate of deforestation changed over time?
The rate of rainforest deforestation around the world has increased over time. Around half of the world’s tropical rainforest has now been cleared. Rates of deforestation increased in all three continents containing tropical rainforest.
38
Identify a tropical rainforest case study you have studied.
Malaysia
39
Identify 4 causes of deforestation.
Slash and burn, road construction, logging, cattle ranching, mining, hydroelectric power and farming.
40
How does slash and burn cause deforestation?
Most clearances are still by the local people and tribes needing land on which to grow crops. They clear the forest by ‘slash and burn’. Vegetation is cut down and then burned. The ash acts as a fertiliser adding nutrients to the soil.
41
How does road building cause deforestation?
Areas of forest have to be cleared to make room for the road itself. Once the road has been built, it allows greater access to the forest, meaning that companies are able to access more areas of forest for commercial logging, mining etc.
42
How does commercial logging cause deforestation?
Commercial logging is chopping down trees to make money from the wood. It is the major cause of primary rainforest destruction in South East Asia and Africa. Worldwide, it is responsible for the destruction of 5 million ha. per year.
43
How does commercial cattle ranching cause deforestation?
Ranching is a major cause of deforestation, particularly in Central and South America. In Central America, two-thirds of lowland tropical forests have been turned into pasture since 1950.
44
How does hydroelectric power cause deforestation?
An unlimited supply of water and ideal river conditions have led to the development of hydroelectric power stations (HEP Stations). This involves building a dam and flooding large areas of the rainforest to make a reservoir.
45
How does farming cause deforestation?
Land is cleared for commercial farming (farming for to make money).
46
How does mining cause deforestation?
The mining of iron ore, bauxite, gold, oil and other minerals can help the country to make money, but involves clearing large areas of the rainforest.
47
How does increasing population cause deforestation?
Population growth has resulted in the loss of tropical rainforest as land is cleared to build houses and infrastructure.
48
Identify 4 impacts of deforestation (including both economic and environmental impacts).
Soil erosion, Loss of biodiversity, Climate change, Economic development, Loss of natural habitat, Loss of native people’s lands
49
Explain the impact of deforestation on soil erosion in your case study location.
Deforestation increases surface runoff and reduces soil stability. Loose soils are quickly washed away by heavy rainfall.
50
Explain the impact of deforestation on biodiversity in your case study location.
Malaysia is home to approximately 15,500 plant species, 746 bird species, 300 mammal species, 379 reptile species, 198 amphibian species and 368 species of fish. The Bornean Orang-utan is now critically endangered due to habitat destruction and illegal hunting.
51
Explain the impact of deforestation on climate change in your case study location.
Forests are the largest terrestrial store of carbon, but deforestation is the second largest source of carbon dioxide emissions, causing 15% of global greenhouse gas emissions.
52
Explain the impact of deforestation on economic development in your case study location.
Deforestation in many parts of the world is driven by profit. Whilst deforestation may result in short-term economic gains, it may lead to long-term losses. Developing land for mining, farming and energy leads to the creation of jobs. Companies pay taxes to the government, resulting in increased investment in public services and facilities.
53
Identify 3 local strategies that can be used to manage the tropical rainforest sustainably.
Afforestation (planting trees), Shifting cultivation, Rubber tapping, Selective logging, Agroforestry
54
What is afforestation?
The opposite of deforestation. If trees are cut down, they are replaced to maintain the canopy.
55
What is shifting cultivation?
When farmers move on to a different location after 2-3 years to allow the rainforest to recover.
56
What is rubber tapping?
More sustainable methods of exploiting the rainforest should be pursued e.g. rubber tapping (getting rubber from trees (this can be done without chopping down the tree.
57
What is selective logging?
Only certain trees (e.g. just the older or inferior ones) are cut down – most trees in the area are left standing. This causes less damage as the trees that remain provide soil cover, avoiding leaching of nutrients and soil erosion and protecting the nutrient cycle. Selective logging allows young trees a guaranteed life span and the forest will regain full maturity after around 30-50 years. This maintains the health of the forest and ensures if can be used by future generations.
58
What is agroforestry?
Growing trees and crops in the same place. This lets farmers take advantage of shelter from the canopy of trees. It prevents soil erosion and the crops benefit from the nutrients from the dead organic matter.
59
Identify 2 international strategies that can be used to manage the tropical rainforest sustainably.
Debt reduction programmes and international agreements
60
How are debt reduction programmes sustainable?
Many tropical rainforests are located in LICs. Many LICs are heavily in debt and often use natural resources such as the rainforest as a way of making money to pay off loans. However, there have been instances when wealthier countries have agreed to write off the debt in return for protecting the rainforest.
61
How are international agreements sustainable?
Tropical hardwood like mahogany is in high demand to make things e.g. furniture. This leads to increased illegal deforestation. Iinternational agreements are in place to make sure only sustainably sourced wood is imported into HICs. An example of this is FSC. The Forest Stewardship council source sustainable timber and mark these products with their logo so people buying the wood know that the wood is sustainable.
62
Describe the location of hot deserts.
Hot deserts are mainly found around the Tropics of Cancer and Capricorn. The hot deserts of the world are located between 15° and 30° north or south of the equator. The largest hot desert is the Sahara in Africa which spans the whole width of the continent. Deserts are typically found towards the west coast of continents.
63
Describe the climate of a desert ecosystem.
The climate is very dry with less than 250 mm of rainfall a year. The climate is very hot. Hot deserts have two distinct seasons: summer, when the temperature ranges between 35-40°C, and winter, when the temperature ranges between 20-30°C.
64
Describe three characteristics of soil in the desert ecosystem.
Desert soils are thin, sandy, rocky and generally grey in colour. Desert soils are very dry. They soak up water quickly when it does rain. The surface of the soil may appear crusty. This is due to the lack of rainfall. As it is so hot water is drawn up to the surface of the soil by evaporation. As the water evaporates, salts are left behind on the surface of the soil.
65
Why does the hot desert have a low biodiversity compared to other ecosystems?
The hot, dry climate is not suitable for many types of life.
66
Identify 6 interdependent features of hot deserts.
Climate, water, soils, plants, animals and humans
67
What are plants with adaptations which allow them to live in hot and dry conditions known as?
Xerophytes
68
Identify 3 ways vegetation has adapted to the hot desert environment.
Deep roots, Small leaves, short life cycles, Spines, Succulents, Wax coated leaves
69
Explain 3 ways vegetation has adapted to the hot desert environment.
Vegetation has small leaves or have no leaves at all. This helps to reduce water loss as there is less surface area for transpiration. Plants have long roots which spread out wide or go deep into the ground to absorb water. Some plants have spines to stop animals from eating them. Succulents e.g. cactus store water in their leaves, stems or roots. Many plants are waxy to reduce water loss.
70
Identify 3 animals that have adapted to the hot desert environment.
Camels, Desert fox, Rattle snake
71
Explain 3 ways animals have adapted to the hot desert environment.
Camels have long eye lashes, hairy ears and closing nostrils help to keep out sand. Thick eyebrows which stand out and shade eyes from the sun, and wide feet so they don't sink in the sand. They can go without water for over a week because they can drink gallons in one go. They can go months without food - they store fat in their humps. They are well camouflaged.
72
Identify the hot desert case study you have studied
Sahara desert
73
Describe its location.
In the North of the African continent. Countries include Morocco, Algeria and Tunisia.
74
Identify four development opportunities in the hot desert area you have studied.
Mineral extraction - Morocco is the world’s largest exporter of phosphate which is used in cleaning products and batteries. Oil and gas - 60% of Algeria's income comes from oil extraction in the Sahara desert. Solar energy - Cloudless desert skies provide great opportunities for solar energy development in the Sahara. Tourism - Many tourists want to visit the desert in Morocco for activities like desert treks.
75
Identify four development challenges in the hot desert area you have studied.
Low population, extreme temperatures, inaccessibility and low water supply
76
Define desertification.
Desertification is the process of fertile land turning into desert over time. Areas on the edge of hot deserts are especially at risk of desertification.
77
Identify four causes of desertification.
Climate change, removal of trees for fuel, overgrazing, over-cultivation and population growth.
78
How does climate change cause desertification?
Hotter and drier conditions are increasing the risk of land turning to desert;
79
How does removal of trees for fuel cause desertification?
Cutting down trees to use the wood for fuel leads to roots dying. The soil will no longer be held together by the roots and erosion will occur.
80
How does overgrazing cause desertification?
Soil becomes bare as the result of vegetation being removed by grazing animals. The soil becomes bare, compacted and prone to drying out and cracking.
81
How does over cultivation cause desertification?
As a population grows there is a greater demand for food. Farming becomes more intensive which means the land has less chance to recover causing it to become infertile, exposed and at risk of erosion.
82
How does population growth cause desertification?
Rising population puts a great demand on resources.
83
Identify four strategies to reduce desertification.
Water and soil management, tree planting, Drip irrigation
84
Define irrigation
Supplying water to crops to help them grow?
85
How can water management be used to reduce desertification?
Commercial farming in hot deserts often involves surface irrigation. Water from deep underground, or from rivers and canals, can be sprayed onto crops or used to flood fields.
86
What is a challenge with using irrigation to reduce desertification?
Too much irrigation can cause problems like salinisation. This occurs because the water often contains salt and it is evaporated quickly because it is so sunny in the desert. This rapid evaporation causes a build-up of salt on the surface of the soil, reducing soil fertility and potentially killing plants.
87
What is drip irrigation?
Using pipes to drip water directly onto the base of the plant
88
Why is drip irrigation more sustainable?
Using drip irrigation on crops instead of surface irrigation means that the soil isn’t eroded by lots of water being added all in one go.
89
How can tree planting reduce desertification?
Trees can be planted to protect soil from wind erosion. Tree roots stabilise the sand which prevents the desert from encroaching on farm land.
90
How can soil be managed to reduce desertification?
Leaving areas of land to rest in between grazing or planting allows them to recover their nutrients. Rotating crops that use different nutrients from the soil means that the same nutrients don’t keep being removed.
91
What is meant by appropriate technology?
cheap, sustainable and easily available materials that are easy for local people to maintain.
92
How can appropriate technology be used to reduce desertification?
Sand fences or terraces can be constructed to stabilise the soil and reduce erosion. The rate of deforestation can be reduced by using solar cookers, which use the sun’s energy to heat food. They are cheap and easy to make, and don’t require fuel wood to work.
