People and the Biosphere Flashcards
(156 cards)
1
Q
Name the 7 biomes
A
Tropical rainforest, tundra, taiga forest, temperate forest, temperate grasslands, desert, savanna
3
Q
What vegetation is there in a desert biome?
A
Plants are scarce and have water storing features, spines instead of leaves and extensive root systems (e.g cacti)
4
Q
What is climate like in a desert biome?
A
Very hot all year (over 30 degrees Celsius) with cool nights (large diurnal temperature range) Very low rainfall (leas than 250mm per year)
5
Q
What vegetation is there in a tropical rainforest?
A
Dense forests with several layers of trees, other plants competing for light
6
Q
What vegetation is there in a savanna?
A
Tall grasses and shrubs and trees which are drought adapted (e.g Baobab)
7
Q
What is climate like in a savanna?
A
Hot all year (25-35 degrees Celsius) with 500-1000mm of rainfall always with a dry season
8
Q
What vegetation is there in a temperate forest?
A
Deciduous trees such as oak
9
Q
What is climate like in a temperate forest?
A
Warm summers (around 18 degrees Celsius) Cool winters (around 5 degrees Celsius) Precipiation all year (1000mm)
10
Q
What vegetation is there in temperate grasslands?
A
Short grasses with very few trees and bushes
11
Q
What is climate like in temperate grasslands?
A
Hot in summer (25 degrees Celsius) Very cold in winter (-40 degrees Celsius) 500-900mm of rainfall per year most in late Spring/Summer
12
Q
What vegetation is there in a taiga forest?
A
Coniferous trees such as pine
13
Q
What is climate like in a taiga forest?
A
Mild summers (10-20 degrees Celsius) very cold winters (below 0 degrees Celsius) Low precipitation (less than 500mm) mainly in summer
14
Q
What vegetation is there in a tundra?
A
Very few plants live here mostly lichens and mosses. Trees and rare and stunted
15
Q
What is climate like in a tundra?
A
Temperatures below 0 degrees Celsius for most of the year and only reaching around 10 degrees Celsius in summer. Low precipitation often less than 250mm. Short daylight hours in winter
16
Q
How are biomes distributed and why?
A
Roughly in belts around the Earth at different latitudes because latitude influences the climate and climate influences type of vegetation that can be found
17
Q
How does climate influence location of biomes? 3 points
A
Most plants need over 5 degrees Celsius to grow so length of growing season varies place to place, plants grow if precipitation is spread over all seasons but not if there is a dry season or if water is frozen in winter, sunshine hours and intensity affect photosynthesis and therefore plant growth
18
Q
What happens to climate as latitude increases?
A
Winters become longer, sunshine hours and intensity decrease because the suns rays are spread out over a larger area and the climate becomes more seasonal
19
Q
Where is precipitation high and why?
A
Rising parts of convection cells because air pressure is low
20
Q
Where is precipitation low and why?
A
At descending parts of cells because air pressure is high
21
Q
Where are forest biomes found and why?
A
Areas of low pressure because warm and wet conditions allow plant growth
22
Q
Where are grasslands and deserts found and why?
A
High pressure areas because lack of precipitation prevents plant growth
23
Q
As latitude increases what is the order of biomes?
A
Tropical rainforest, tropical grassland, desert, temperate grassland, temperate forest, taiga forest, tundra
24
Q
Which biome has the greatest temperature range?
A
Desert
25
Q
Which biome has the greatest rainfall?
A
Tropical rainforest
26
Which biome has the least rainfall?
Desert
27
Define abiotic factors
Non living part of a biome. Includes water, soil, rock and the atmosphere
28
Define biotic factors
Living part of a biome, made up of plant and animal life
29
Define altitude
Height of land
30
Define drainage
The ability of soil to allow water to flow away
31
Define flora
Plants of a particular region or habitat
32
Define fauna
Animals of a particular region of habitat
33
By how much do temperatures drop for every 1000m increase in height?
6.5 degrees Celsius
34
How does altitude affect vegetation found? 5 points
At high altitudes temperatures can be below freezing which limits plant growth, mountains are exposed to wind and rainfall gets heavier the higher you go which doesn’t suit all plants, soils in mountains get thinner which makes it difficult for large plants to grow therefore trees in forest biomes get shorter higher up the mountain, at tree line it becomes too cold and trees cannot grow so grasses grow afterward, tropical rainforests only found below 1000m
35
How does drainage affect vegetation? 4 points
Where there are impermeable rocks the surface may often be waterlogged because rain can’t drain away and only certain plants like to grow in these conditions, the amount of drainage affects amount of evaporation from soil, some plants like wet conditions but others prefer to grow where it is dry
36
How does soil type affect vegetation? 6 points
Some rocks are harder than others which makes it more difficult for plants to grow through them, permeability of rocks affects whether or not there is enough water for plants to grow, chemically weathered rocks release nutrients and chemicals into soil so soils are neutral, acidic or alkaline depending on rock type which affects the type of plants which grow, Sandy soil has small air gaps and water flows though easily so plants must be able to stand dry conditions, clay soil has few air gaps so water will not flow through and plants need to be adapted to wet conditions , peat does not contain rock particles and it is made from old rotted plants which makes it rich in nutrients therefore forests grow
37
What is the link between flora and atmosphere?
Plants take in carbon dioxide and release oxygen which changes the gases in the atmosphere
38
What is the link between fauna and atmosphere?
Animals take in oxygen and release carbon dioxide which changes gases in the atmosphere
39
What is the link between flora and fauna?
Animals eat plants
40
What is the link between flora and water?
Plants need water for photosynthesis
41
What is the link between fauna and water?
Animals drink water for survival
42
What is the link between water and rock?
Permeable rocks allow water to percolate
43
What is the link between rock and soil?
Weathering of rock provides nutrients
44
What is the link between water and soil?
The more small air gaps a soil has, the more water can flow through
45
What is the link between rock and flora?
Tree roots open cracks in rocks which contributes to biological weathering. Permeability of rocks affects how much water there is for plant growth
46
What is the link between fauna and rock?
Biological weathering occurs when animals wear away rocks
47
What is the link between soil and flora?
Plants absorb water and nutrients from the soil through their roots
48
What is the link between water and atmosphere?
When water evaporates in high temperatures, it enters the atmosphere as water vapour
49
What is climate like in a tropical rainforest?
Hot all year (25-35 degrees Celsius) Wet all year (average annual precipitation 2000-3000mm)
50
What four things does the biosphere provide for indigenous people?
Food, medicine, building materials, fuel resources
51
How does the biosphere provide food? 3 ways
Natural vegetation can be replaced with crops like wheat and rice, meat and fish are part of the biosphere, sustainable harvesting of nuts, berries, fruits
52
How does the biosphere provide medicine?
Periwinkle plant is used to treat leukaemia and Hodgkin’s disease, poppies are the source of morphine painkiller, aloe plant has soothing properties and aloe Vera is used in many cosmetics
53
How does the biosphere provide building materials?
Straw the dry stalks of cereal plants is used for roofing and for insulation, animal dung can be mixed with clay and straw to make bricks, timber which is essential for construction comes from trees
54
How does the biosphere provide fuel resources?
Wood from shrubs and trees, animal dung is dried and burnt as fuel, biofuels convert plant products to fuel through a range of different processes: one example is bioethanol made by fermenting crops like sugarcane
55
What happens as the value of the biosphere becomes more well known?
The biosphere has become increasingly exploited for commercial gain
56
How does the demand for water affect the biosphere?
There is an increasing demand for water around the world as populations have grown, especially in cities which has led to more industry and agriculture which needs more water, water is taken from areas which have more which impacts the biosphere
57
Give 2 examples of the biosphere being exploited for water
The Hamoun wetlands in Iran has been extracted for irrigation (watering crops), dams have been built in neighbouring Afghanistan which limits the water they get
58
How does the demand for energy affect the biosphere?
Growth of biofuels, mining and dams for hydroelectric power affects the biosphere, biofuels are valuable alternatives to fossil fuels and large areas of vegetation have been cleared to make room to grow biofuels, if oil is below ground this can cause pollution
59
Give an example of the biosphere being exploited for energy
Mining for oil in Ecuador’s Oriente Rainforest led to more than 600 waste pits full of oil that leaked into local water supplies, many species disturbed including the periwinkle plant which became extinct in the region
60
How does the demand for mineral resources affect the biosphere?
Mineral resources are often found within valuable areas of the biosphere, when these are mined large areas of land are cleared which reduces the biodiversity of an area
61
Give an example of the biosphere being exploited for mineral resources
Mountain top removal mining: access to coal is made easier by removing mountain tops, first done in the Appalachian mountains in the USA
62
Identify 3 services the biosphere provides
Regulates the atmosphere, maintains soil health, regulates water in the hydrological cycle
63
How does the biosphere regulate the atmosphere? 3 points
Keeps oxygen and carbon dioxide in balance in the atmosphere, plants take in carbon dioxide through photosynthesis which reduces how much is in the air (important because carbon dioxide contributes to photosynthesis) therefore rainforests can be called ‘carbon sinks’, plants produce oxygen during photosynthesis which keeps the level of oxygen in the atmosphere at the levels needed for animals and humans to breathe
64
How does the biosphere maintain soil health? 3 points
IThe thing which makes soil fertile is the dead plants and leaves that rot down and add nutrients to the soil: this rich fertile soil is called humus, without plants rotting down the soil would not be able to support growing organisms, the breaking down of plants and leaves is helped by the biosphere as earthworms, fungi and bacteria all help to break it down
65
How does the biosphere regulate water in the hydrological cycle? 3 points
Biomes, particularly forest biomes, help to regulate the water cycle through interception and infiltration, mangrove forests along coastlines help prevent coastal flooding and as they grow in tropical areas where cyclones are more likely they are especially important
66
Which of the biospheres services is most important and why?
Regulating the atmosphere is the most important as it impacts us, socially and the earth, environmentally in both long and short term. In the long term, climate change is a significant problem as sea levels are rising, ice caps are melting and droughts are occurring more often. This would affect people economically as it prevents growth of crops which they earn income from and it affects them socially, this affects the earth environmentally because rising sea levels could cause the Gulf Stream to be diverted, leading to lower temps in Western Europe
67
What are the three stores of the nutrient cycle?
Biomass (mainly plant tissue), litter (leaves fallen to the ground), soil (composed of rock particles
68
Define fallout
Dead plants and animals become litter on the soil surface
69
Define run off
Water washes litter away ,removing nutrients
70
Define weathering
The chemical breakdown of rocks adds nutrients to the soil
71
Define growth/uptake
As plants grow they take nutrients from the soil
72
define precipitation
Rainfall adds nutrients
73
Define leaching
Nutrients are washed out of the soil as water moves through
74
Identify 4 factors which affect exploitation of the biosphere
Population increase, increase in GDP (the number of people in middle class is expected to increase from 1.8 billion to 4.9 billion by 2050), changes in sectors of employment (agriculture, services, industry), urbanisation (the world is 54% urban and by 2050 this will be 66%)
75
Define decay
Litter decomposes, returning nutrients to the soil
76
Which area has always had the highest population and how much has it increased?
East Asia and Pacific. Between 1960-2010 increased from just above 1 billion to about 2.3 billion
77
How does population increase affect the biosphere?
More people to provide for means a higher demand for resources
78
What is the general trend for the worlds GDP between 1990-2030?
Has increased dramatically. One region which now contributes a lot to the worlds GDP now is China
79
What is the general trend of world population between 1960-2010?
Every region has an increased population however some have increased more rapidly than others. For example East Asia and Pacific has increased from just above 1 billion to about 2.3 billion
80
How does increased GDP affect exploitation of the biosphere?
With increased wealth comes increased demand for resources because people can afford more food and also cars which require fuel resources
81
How many megacities are there?
25
82
How does growth of megacities/urbanisation affect exploitation of the biosphere?
Urbanisation causes an increase in the city’s population, therefore there is an increased demand for resources becAuse a city needs a lot to support all its residents e.g food, water, shelter but these resources are not always collected locally, they are sometimes collected nationally or even globally
83
How has China’s economy (agriculture, services, industry) changed over time?
The secondary industry has almost doubled,primary industry had decreased massively and tertiary has increased slightly
84
How has the change in china’s economy affected exploitation of the biosphere?
Secondary industry involves jobs like mining which require a lot of fuel resources and aim to take resources from the ground
85
What is Thomas Malthus’ theory about population and resources?
In 18th century he said population would grow faster than food production (geometrically rather than arithmetically) which would cause a disaster. The population would then crash due to positive checks (e.g famine) and preventative checks (e.g having fewer children)
86
What evidence is there for Malthus’ theory?
Wars and civil wars have and still do take place as well as droughts and famines and spread of diseases like bird flu and Ebola
87
How can technology increase food production?
The Green Revolution uses selective plant breeding, irrigation, pesticides, artificial fertiliser and more efficient machinery which has led to increased yields in many places around the world. One of the early successes of this scheme was the development of a variety of rice in the Philippines in the 1960s-IR8 which was one of the first high yield varieties because the amount of crop that could be harvested from an area was much higher for traditional rice varieties, IR8 increased yield from about 1 tonne to 10 tonnes per hectare
88
What is Ester Boserup’s theory about population growth and resources?
In 1960s she said as the population size approaches the point when food and resources may run out then human ingenuity will find ways of increasing food and resource production enough to meet the increased demand. ‘Necessity is the mother of invention’ is a saying which has been applied to her theory. As the carrying capacity of a country increases people will find solutions
89
Define carrying capacity
The number of people who can actually be supported by the resources
90
Give 4 pieces of evidence to support Boserups theory
In the 20th century the worlds population increased from 1.5billion to 6billion but there has not been a worldwide crash in population, Green Revolution, development of alternative renewable energies such as solar, hybrid, electric cars. Birth control and changes to culture have lowered birth rates, as countries develop, their birth rates tend to decrease
91
Give 2 pieces of evidence against Boserups theory
AIDS pandemic, growing number of refugees fleeing fighting and natural disasters
92
Which theory :Malthus or Boserup is more realistic for the future of the world?
Boserups theory is more realistic given that she has been proved correct on more occasions however this theory is not representative of the developing world. The Malthusian view is more appropriate as they are less able to create new ways to reduce water and energy consumption
93
What is the relationship between biotic and abiotic factors?
Interdependent -they rely on eachother
94
Define producer
Plants: they are the beginning of the tropical rainforest food chain, they make food using the suns energy with a process called photosynthesis
95
Define primary consumer
Organisms that consume only plants (herbivores). Some samples are Howler monkeys, fruit bats and the blue macaw
96
Define secondary consumers
Animals that eat primary consumers. Included in this level of the food chain are carnivores such as tigers, Jaguars and pumas and omnivores such as spider monkeys and toucans
97
Define decomposer
Eat dead animals and plants, they break down nutrients in the dead matter which is then returned to the soil. They are the last link in the food chain, the nutrients they supply feed the producers at the top of the food chain
98
How are evergreen hardwood trees adapted to the rainforest?
They have tall slim trunks with no branches on them, they have huge buttress roots to support the weight of the plant so it can grow tall to collect sunlight, they spread over the surface of the ground as the soil is thin and nutrients are concentrated in the top layer so roots have to be shallow
99
Give an example of biotic and abiotic factors being interdependent
Plants are dependent on the climate because they require sunlight to make food
100
How are rainforest plants leaves adapted to rainforest climate?
Most plants have waxy thick leaves (to prevent water loss inside leaf) with drip tips so water runs off them quickly otherwise mould and moss would grow over the wet surface of the leaf and block its sunlight , they shed leaves quickly to prevent leave rotting
101
How are epiphytes adapted to the rainforest?
These plants live in the canopy on trees and have evolved to get all their nutrients from water and air rather than the soil (which is 10m below) so their roots dangle in mid air
102
How are sloths adapted to the rainforest?
Have huge claws to allow them to hang upside down in the branches, their fur grows away from their feet to help shed rain water whilst upside down. Green algae grows in their fur to help them camouflage from predators
103
How are primates adapted to the rainforest?
Lemurs and monkeys have evolved to life in the canopy where most food is; their long tails are used for balanced and most have strong claws to grip trees and branches
104
Why are emergents?
Plants which have specialised to grow extremely tall, 50m or more
105
At what height do trees form the rainforest canopy?
30-40m
106
What happens when a gap appears in the canopy when an old tree dies and falls?
Light reaches the forest floor and tree saplings race upwards to the light, the gap is quickly filled as the winner spreads out its broad leaves to capture the maximum amount of sunlight
107
What is the main challenge in the TRF?
Light
108
How many plant and animal species are found in the rainforests on the Island of Madagascar?
An estimated 14,000 plant species, 250,000 known animal species -75% of which are not found anywhere else in the world. 300 species of frog, over 459 species of spider and 700 species of butterfly
109
How are birds adapted to the TRF?
Birds of prey such as eagles have evolved powerful legs with clawed talons that can grab monkeys from the canopy
110
How do animals camouflage in the TRF to avoid being eaten? 2 ways
Insects mimic sticks and leaves while birds have colouration and barring (stripes) that make them hard to see
111
Which is the biggest store in the TRF?
Biomass which is made up of all living things in the TRF. When leaves fall or branches drop into the litter store they decompose very quickly. As soon as the nutrients are released into the soil, the plants of the TRF quickly start to absorb them
112
Why are some stores and transfers of nutrients in a tropical rainforest so large? (Describe 5 stages)
As plants and animals die their tissues fall into the litter store. As living tissue decomposes, nutrients are transferred to the soil store. Some nutrients are lost from litter by surface runoff. Plants take nutrients from the soil which is very rapid in the TRF. Soil loses nutrients by leaching
113
Where are most tropical rainforests located?
20 degrees north or south of the equator
114
Why is there a high level of biodiversity in the TRF?
The conditions for plant growth are very good which allows ecosystems to support thousands of different plant species. TRFs are ancient ecosystems which have developed over hundreds of thousands of years and many different species have evolved to meet the various challenges of the forest. The forest is arranged in 5 stratified layers and each of the plants in each layer has different characteristics based on how much light is there
115
Why is there a complex food web in the TRF?
The climate is very hot and wet which encourages plant growth. This means there are a lot of producers which supports the primary consumers who live off plants and the secondary consumers who live off primary
116
Identify 3 direct threats to the TRF
Deforestation for: commercial hardwood logging, agriculture, mining, fuel wood
117
Identify the 5 layers of the forest
Forest floor, under storey, canopy, the emergent layers
118
How is commercial hardwood logging a threat to the TRF?
In the 20th century many countries sold rainforest timber for money to pay interest on international debts. Illegal logging occurs for 3 reasons: 1.high demand for hardwood timber especially rosewood, Chinese buyers pay high prices for this. 2.people who live near rainforests are very poor and illegal logging pays well. 3.police and government officials often let illegal logging occur in return for money
119
How is commercial agriculture a threat to the TRF?
Commercial agriculture involves crops being grown to be sold for profit it’s the leading cause of TRF deforestation
120
How does commercial agriculture in Brazil affect the TRF?
Most of rainforest deforestation (75%) in Brazil over last 20 years was caused by cattle farming. Beef is one of Brazil’s key exports, most Brazilian rainforest clearance has been in order to grow sugarcane
121
How does commercial agriculture in Indonesia affect the TRF?
Palm oil plantations (6 million hectares) -palm oil is increasingly used to make biodiesel. Huge areas of forest are burnt to make room
122
How is mining a threat to the TRF?
Some rainforests are on top of valuable material. Often most economic to use open cast mining to extract the materials which affects large areas of rainforest. Roads built to access mines encourage farmers and loggers to move in. An estimated 15% of deforestation is linked to mining and road building
123
Give an example of mining affecting the TRF
Coltan (mineral used in mobile phones) is mined in the democratic republic of Congo. Coltan is dug from ground in shallow mines by poor families, sold for a few pence to TNCs who sell it on. Large areas of forest cleared for mines
124
How is fuelwood a threat to the TRF?
People living in rainforests or near them use them as a source of fuel. Population increase has sped up rates of deforestation . Rainforest are a major source of charcoal
125
Give an example of the threat of fuelwood to the TRF
Charcoal is a very important fuel source in many African cities
126
How does climate change affect the TRFs abiotic factors? 6 points
Warming global temperatures affect the atmosphere systems that bring wet seasons to the equatorial climate, this means systems shift polewards and don’t bring as much rain. Rainforests likely to become hotter and drier so more droughts. Droughts increase risk of forest fires. Rainforests could become sources of carbon dioxide not carbon dioxide sinks, could accelerate global warming. Long term, stressed TRFs may turn into grasslands
127
How does climate change affect the TRFs biotic factors? 4 points
Species in TRF are not adapted to deal with heatwaves because temps stay the same all year round. TRF species are not adapted to survive forest fires or long droughts. Other plant species adapted to hotter drier conditions (eg Baobab) spread and out compete TRF species. Rainforest plants and animals have lower resistance to new pests and diseases (ECOSYSTEM STRESS)
128
Give 2 examples of climate changes effect on the TRF
By 2100 between 30% and 60% of Amazon rainforest could become a dry savanna, whole colonies of flying fox bats have died as heat levels have spiked above limits they can tolerate
129
How is subsistence agriculture a threat to the TRF?
People farm to feed their families. Trees cut down on a small plot and the undergrowth burned; crops are then planted. The nutrients in the soil are quickly leached out and weed growth takes over. Then the farming family often decides to clear another plot; this ‘slash and burn’ method makes sense as no money is needed to clear the land. Rapid population in developing countries means more people are clearing rainforest land and reusing plots straightaway so soil loses all nutrients and is abandoned
130
What fraction of deforestation is caused by subsistence farmers?
One third
131
When did the Amazon suffer two droughts and what did this cause?
2005 (a 1 un 100 year drought) and 2010. The Amazon switched from absorbing carbon dioxide to emitting it because plants stopped growing and stopped absorbing carbon dioxide. Forest fires broke out, burning trees and litter and releasing carbon dioxide
132
How does drought affect leaves? 2 points
Dries out the leaf litter so decomposer organisms die out threatening the nutrient cycle, causes leaves in the canopy to die which reduces food supply and affects food webs
133
What did scientists argue after a drought in Amazonia in 2014?
Deforestation is making droughts more common, with fewer trees there is less evaporation and transpiration which means less clouds and rain
134
When was CITES founded?
1975
135
What does CITES stand for and what is their aim?
Convention on International Trade un Endangered species. They hope to stop illegal hunting and collecting of endangered species by stopping buying and selling them
136
How does CITES work?
Countries sign up (180 have already) and agree to monitor trade across its borders to catch and punish people exporting or importing goods made from endangered species. Lists 34,000 species (animal and plant e.g red pandas), bans cross border trade in listed countries
137
What does REDD stand for and what is the aim?
Reducing emissions from deforestation and forest degradation. Aim to stop deforestation (20% of carbon dioxide emissions, main cause of global warming)
138
When was REDD founded?
2012
139
Identify 4 advantages of CITES
Reducing ivory trade, halting decline of African elephants, most successful protection of species tends to be those which are high profile like the snow leopard, huge international influence as 181 countries have signed up
140
Identify 3 disadvantages of CITES
Species need to be under threat in order to be protected, relies on countries setting up and funding monitoring systems which is difficult for developing countries, protects species not ecosystems (deforestation does not stop), difficult to check all countries are enforcing the CITES rules and in 2014 over 1000 rhinos were killed in South Africa by poachers
141
Identify 2 advantages of REDD
Provides international expertise to develop best approaches, funding that it has access to (because it is backed up by the United Nations) is very attractive to governments for example in Brazil REDD is backed up by a $1 billion fund
142
How does REDD work ?
Encourages sustainable management of forest. governments and TNCs in developed countries find projects to conserve forests in developed countries to offset carbon dioxide emissions and meet their targets
143
Identify 4 disadvantages of REDD
Some regions have signed up to the scheme where deforestation still occurs rapidly, vague about what counts as forests for replanting (some rainforests have been replanted with oil palm trees which still degrades the environment), corruption- money goes to developed countries which could be spent on other things, it costs $38 billion a year to reduce deforestation by 50%
144
Identify two small scale initiatives in the TRF
Ecotourism, sustainable farming
145
Describe ecotourism in the TRF
Costa Rica used to lead the world in deforestation and to battle this they have created national parks and turned rainforests into tourist attractions. People pay for a guide so there are economic benefits. Small scale tourism doesn’t bring in a lot of income but large scale tourism would destroy the rainforest
146
Describe sustainable farming of crops in the TRF
A man bought a farm which was partially barren but when the forest began to grow onto it he planted new species of plants. He sold these as organic produce (each week a crop of bananas is ready to be harvested, cacao is produced which are native crops) he can live off these and make a profit -long term
147
Describe sustainable farming of trees in the TRF
Take advantage of trees which have fallen down rather than cutting them down, cut these trees into logs which can be used for timber. Buffalo drags timber in and out -low cost, low degradation to environment (no roads). Timber can be used to build lodges for tourist so thing links back to ecotourism
148
How does poor drainage affect plant growth along a river?
Causes waterlogged conditions like bogs and swamps where only a few specialist plants can grow
149
Identify 3 ways the biosphere acts like a life support system for us
Regulates the water cycle -plants slow the flow of water to rivers and filter water to make it clean, regulates gases that make up the atmosphere -plants absorb carbon dioxide and produce oxygen for us to breathe in, keeps soil healthy for plants to grow -new nutrients are provided by rotting plant material
150
Identify 3 ways a chameleon is adapted to living in the TRF
Use camouflage to protect itself from predators by changing skin colour to match surroundings, they have feet adapted to gripping branches and a tail that can wind round branches in the canopy
151
Describe the TRF nutrient cycle in 4 points
Plants grow all year in huge numbers, dead matter drops to the floor and decomposes quickly in the warm wet conditions, fast growing plants take up nutrients very quickly, constant precipitation leaches nutrients down through the deep rainforest soil
152
Identify 7 reasons for deforestation of the TRF
Electricity (hydroelectric power dams), wood for fuel, commercial agriculture, subsistence agriculture, biofuels, commercial hardwood logging
153
Why has deforestation rate fallen in Brazil?
Government policies aim to reduce deforestation such as withdrawing grants to clear rainforest land, economic development has made Brazil's exports more expensive and farming less profitable
154
Why has deforestation rate increased in Africa?
Rapid population growth is combined with poor people using wood for fuel and clearing forest for farmland
155
What is sustainability?
The ability to keep something going at the same rate/level. The key ideas to consider are: keeps going without using up natural resources, doesn't require lots of money to keep it going, meets the needs of people now and in the future without having a negative effect
156
What 4 things does sustainable biosphere management do?
Ensures the ecosystem can recover quickly from any use, prevents damage to the environment/ecosystem, helps local people to benefit from their environment/ecosystem, helps local people understand why this management benefits them
157
How do ecotourism and sustainable farming protect remaining rainforest from deforestation?
Ecotourism gives jobs like tourist guides to local people and therefore they can get money from tourists coming to see the rainforest so they want to protect it, sustainable agriculture reduces the need for farmers to clear new plots of land in the forest because using better fertilisers and farming techniques allows farmers to keep using the same plots year after year and to get better yields from their land
