2.A - Global Systems: The Water and Carbon Cycles Flashcards
(204 cards)
1
Q
What is the chemical symbol for carbon?
A
C
2
Q
What is the nickname carbon is known by?
A
“The building block for life on Earth”
3
Q
What do we mean when we say carbon is versatile?
A
It has the ability to bond with other elements.
4
Q
Why is carbon nicknamed “the building block for life on Earth”?
A
Due to its versatility.
5
Q
What do we mean by carbon is ubiquitous?
A
It is found everywhere on the planet.
6
Q
What is the global carbon cycle?
A
The closed system which constantly cycles carbon across the spheres of the Earth.
7
Q
What type of systems are the smaller, more localised versions of the carbon cycle?
A
Open systems
8
Q
We can study the carbon cycle by looking at flows between:
- ?
- ?
- ?
A
- The land and the ocean (the fast carbon cycle)
- The oceans and the atmosphere
- The land and the oceans
9
Q
Which carbon cycle is called the fast carbon cycle?
A
The carbon cycle between the land and the atmosphere.
10
Q
What are the 4 flows in the fast carbon cycle?
A
- Photosynthesis
- Respiration
- Decomposition
- Fossil fuel combustion
11
Q
What is photosynthesis?
A
The flow which transfers carbon dioxide from the atmosphere into living organisms by combining it with water to form glucose.
12
Q
What happens during photosynthesis?
A
Carbon dioxide is combined with water from the soil to form glucose.
13
Q
Which organisms conduct photosynthesis?
A
Plants
14
Q
What is released as a by-product of photosynthesis?
A
Oxygen
15
Q
What are the 2 variations in photosynthesis?
A
- Spatial variation
2. Temporal variation (diurnal and seasonal)
16
Q
Describe the diurnal variation in photosynthesis.
A
The flow operates unevenly over time. It is greater during the day when the sun is out, as it is powered using energy from the sun.
17
Q
Describe the seasonal variation in photosynthesis.
A
It is greater during seasons like summer when there are greater hours of daylight.
18
Q
Describe the spatial variation in photosynthesis.
A
Caused by climatic factors such as temperature.
19
Q
What is carbon sequestration?
A
The natural capture and storage of carbon dioxide from the atmosphere by physical and biological processes.
20
Q
True or False? : Photosynthesis is an example of carbon sequestration.
A
True
21
Q
What is respiration?
A
The flow which transfers carbon dioxide back into the atmosphere from living organisms as they break down glucose to produce energy.
22
Q
What are the 2 products of respiration?
A
Carbon dioxide and water
23
Q
True or False? : Respiration does not vary spatially and temporally?
A
False - Respiration does vary spatially and temporally.
24
Q
Which 2 flows develop the fast carbon cycle?
A
Photosynthesis and respiration.
25
True or False? : In the fast carbon cycle, photosynthesis and respiration are balanced.
False - Photosynthesis is greater than respiration.
26
Why is photosynthesis greater than respiration in the fast carbon cycle?
Some of the carbon stored in organisms from photosynthesis is buried with them when they die and incorporated into sedimentary rocks, so less carbon is available to be respired.
27
What is decomposition?
The break down of an organism’s bodily cells due to physical, chemical and biological mechanisms.
28
Give 2 examples of physical mechanisms in decomposition?
Wind and rain
29
Give 2 examples of chemical mechanisms in decomposition.
Leaching and oxidation
30
Give 2 examples of biological mechanisms in decomposition.
Feeding and digestion (by microbes/bacteria and fungi)
31
What does decomposition do to carbon?
Releases it back into the atmosphere.
32
True or False? : Rates of decomposition vary spatially and temporally.
True - decomposition is faster in warmer, humid conditions and slower in cooler, dryer conditions.
33
What are fossil fuels?
The carbon-based remains of organisms that can be burned in the presence of oxygen to release carbon dioxide.
34
Give 3 examples of fossil fuels.
Coal, gas and oil
35
What percentage of global energy consumption is sourced from fossil fuels?
85%
36
What 2 forms does carbon take in the oceans?
Dissolved carbon dioxide and carbon compounds in marine organisms.
37
What are the 2 pumps in the ocean which remove carbon from the atmosphere?
The organic pump and the inorganic pump
38
Describe the inorganic pump in the carbon cycle between the ocean and the atmosphere.
Slowed pump which operates via diffusion.
39
What does the carbon content of the oceans determine?
Acidity of the oceans.
40
In the inorganic pump in the carbon cycle between the ocean and atmosphere, what happens to colder water?
It is denser so it sinks.
41
What drives the organic pump in the carbon cycle between the ocean and the atmosphere?
Phytoplankton
42
What are phytoplankton?
Microscopic plant life which captures energy from the sun through photosynthesis.
43
Where do phytoplankton live in the oceans?
In the euphotic zone.
44
What is the euphotic zone of the oceans?
The part where sunlight penetrates.
45
What do the phytoplankton do in the euphotic zone?
Photosynthesise
46
Where do phytoplankton sit in the ocean food chain?
At the bottom.
47
What happens as phytoplankton are consumed in the ocean food chain?
They transfer carbon along the food chain.
48
What is the 3rd, potential and lesser-known way that carbon may be transferred between the ocean and the atmosphere?
Acid rain, either anthropogenic or natural.
49
What is the slow carbon cycle?
The carbon cycle between the oceans and the land
50
What drives the slow carbon cycle?
Weathering
51
What is weathering?
The physical, chemical or biological break down of rocks into smaller particles.
52
What is carbonation?
A type of chemical weathering where rainwater containing carbonic acid falls onto rocks containing calcium carbonate to produce soluble calcium bicarbonate.
53
How is calcium bicarbonate transferred into the oceans?
Runoff, where it is carried as part of the solute load.
54
What happens to calcium bicarbonate once it is in the oceans?
It is used by marine organisms to create shells.
55
What happens to marine organisms and their shells when they die in the slow carbon cycle?
They deposit their carbon-rich shells on the ocean floor where they are lithified (turned into rock).
56
What is lithification?
The process of turning sediment into rock.
57
How is carbon returned to the atmosphere in the slow carbon cycle?
Through volcanism when a subducting plate causes the rocks to melt.
58
What is the biggest global store of carbon, and how much carbon (gigatonnes) is stored in it?
Sedimentary rocks and deep ocean sediments - 100,000,000
59
How much carbon (gigatonnes) is stored in the oceans?
38,700
60
How much carbon (gigatonnes) is stored in sea floor sediments?
6,000
61
How much carbon (gigatonnes) is stored in fossil fuels?
4,130
62
How much carbon (gigatonnes) is stored in soils and peat?
2,300
63
How much carbon (gigatonnes) is stored in the atmosphere?
600
64
How much carbon (gigatonnes) is stored in the biosphere?
560
65
True or False? : Carbon in the biosphere is equally distributed among the ecosystems.
False - it is unevenly distributed.
66
What percentage of carbon found in the biosphere is found in the world’s forests?
50%
67
Where is carbon mainly stored in forest ecosystems?
In trees
68
What is a boreal forest?
A forest characterised by coniferous trees.
69
What is taiga?
Another term for boreal forests.
70
What percentage of carbon found in the biosphere is found in boreal forests?
26%
71
What is the largest ecosystem carbon store in the biosphere!
Boreal forests
72
What is the second largest ecosystem carbon store in the biosphere?
Tropical rainforests
73
What percentage of carbon in the biosphere is found in the tropical rainforests?
20%
74
Why are boreal forests greater stores of carbon than tropical rainforests, despite the fact tropical rainforests have more biomass?
Boreal forests cover a greater area of land.
75
What percentage of carbon found in the biosphere is stored in green plants?
20%
76
What characterises a tropical rainforest?
Heavy conventional rainfall, high humidity, a lushness of vegetation and nutrient-rich, shallow soil.
77
Where are the world’s tropical rainforests located?
Around the Equator between 10°N and 10°S in South America, Africa and Asia, at elevations below 1000m above sea level.
78
What are the 3 major rainforests?
1. The Amazon rainforest in South America
2. The African rainforest
3. The Indo-Malaysian rainforest
79
Describe the location of the Amazon rainforest.
Located either side of the Equator in South America, stretching from the eastern slopes of the Andes to the Atlantic Ocean.
80
What percentage of Brazil is occupied by the Amazon?
68%
81
What countries does the Amazon rainforest occupy?
Brazil, Peru, Bolivia, Colombia, Ecuador, Venezuela, Guyana, Suriname and French Guiana.
82
How big is the Amazon rainforest?
7.3 million km2
83
Describe the climate of the Amazon in 2 words.
Hot, wet
84
What are temperatures like in the Amazon rainforest?
High and constant throughout the year with little variation. Between 25 and 32°C.
85
True or False? : The Amazon does not show great diurnal change.
True - the diurnal temperature range is 10°C.
86
What is insolation like in the Amazon rainforest?
Evenly distributed throughout the course of the year.
87
True or False? : A day in the Amazon is evenly split between light and darkness.
True - 12 hours of daylight, 12 hours of darkness.
88
What is the rainfall like in the Amazon rainforest?
Heavy conventional rainfall. Most afternoons have a heavy shower.
89
What is evapotranspiration like in the Amazon rainforest?
Rapid from rovers, swamps and trees.
90
What does the climate of the Amazon produce?
An all-year-round growing season.
91
How many species of fish are there in the Amazon?
3,000
92
How many species of birds are there in the Amazon?
1,300
93
How many species of amphibian are there in the Amazon?
428
94
How many species of mammal are there in the Amazon?
427
95
How many species of reptile are there in the Amazon?
387
96
What birds can you find in the Amazon?
Toucans, macaws and harpy eagle
97
What insects can you find in th Amazon?
Butterflies, bees, ants
98
What mammals can you find in the Amazon?
Monkys, bats, jaguars, sloths, ant-eaters, river dolphins, manatees and capybara.
99
What reptiles can you find in the Amazon?
Crocodiles and snakes
100
What amphibians can you find in the Amazon?
Frogs
101
What fish can you find in the Amazon?
Piranhas
102
What 3 reasons explain why species diversity is high in the Amazon?
1. The rainforests have developed over a long time, allowing complex food webs to develop.
2. The climate allows for constant reproduction throughout the year.
3. Growth isn’t restricted by water supply.
103
How many species of trees can you find in 1km2 in the Amazon?
3,000
104
What produces vertically stratified layers of vegetation in the Amazon?
Intense competition for sunlight
105
What is the emergent layer of the Amazon?
The top layer where trees can reach up to 50m in height.
106
What are the leaves like in the emergent layer of the Amazon, and how does this help the tree?
Small in order to reduce transpiration due to their expose to the wind and sunlight. They have a thick cuticle and waxy surface in order to help shed rainfall and protect against strong levels of insolation.
107
What is the canopy layer of a tropical rainforest?
The 2nd layer which forms a continuous cover.
108
What percentage of sunlight is absorbed by the canopy layer of the tropical rainforest?
70%
109
What percentage of rainfall is intercepted by the canopy layer of the tropical rainforest?
80%
110
How does the canopy layer affect lower layers of the tropical rainforest?
It shades them and protests them from soil erosion.
111
What is the shape of a canopy layer leaf?
They have umbrella-shaped crowns and large leaves. This maximises their exposure to sunlight.
112
Why do the trunks of a canopy layer tree only begin to branch out near the crown?
In order to conserve energy whilst growing tall.
113
What is the undercanopy layer?
The 3rd layer of the tropical rainforest trees.
114
Describe the shape of an undercanopy layer tree.
Conical shape - narrow crows in comparison to their height.
115
What type of tips do the leaves of the undercanopy layer have?
Extended apical ends (drop tips) which remove water from the surface so transpiration can take place unhindered.
116
Why is it important that the undercanopy trees can transpire unhindered?
Because humidity is high and there is a lack of wind.
117
What is the bottom layer of the tropical rainforest?
The shrub and herb layer.
118
What types of plants live in the shrub and herb layer?
Parasitic plants which live on other organisms.
119
True or False? : The shrub and herb layer is very bright.
False - not 5% of insolation reaches the tropical rainforest floor.
120
How thick is the bark of tropical rainforest trees and how is bark an adaptation?
1-2mm thick, and smooth to shed rainfall easily.
121
Why is the tropical rainforest floor not covered in a thick layer of litter?
Because organisms (termites, fungi, bacteria, worms and ants) thrive in the wet conditions and decompose dead organic matter.
122
Where is vegetation dense in the tropical rainforest and why?
Along riverbanks where sunlight can penetrate the canopy layer.
123
Where are the majority of nutrients in the tropical rainforest stored?
In biomass
124
What allows for the rapid decomposition of dead plant material on the tropical rainforest floor?
The hot, damp conditions.
125
Why do nutrients not remain in the soil for long in the tropical rainforest?
They are in high-demand from the rainforest's fast-growing plants.
126
Describe the state of the rainforest soil in terms of nutrients.
Sterile - nutrients do not stay in the soil for long, and remain near the surface.
127
What happens to rainforest leaves when they fall to the forest floor?
They are quickly broken down by decomposers into humus.
128
Give 3 example of decomposers in the tropical rainforest.
1. Bacteria
2. Fungi
3. Termites
129
What is humus?
A black substance left behind following the decomposition of organic litter (leaves).
130
Explain the rainforest nutrients cycle.
Nutrients are recycled quickly as they are in high demand from the rapidly-growing trees. Organic litter falls to the forest floor, where decomposers break it down into humus and return the nutrients to the soil. It remains in the upper horizons and is quickly re-absorbed.
131
How does deforestation affect the rainforest nutrients cycle?
Fewer leaves fall to the forest floor, so there is less litter and less nutrients returned to the soil.
132
How many gigatonnes of carbon is stored in the biomass and soil of the tropical rainforest?
550 gigatonnes
133
What is the concentration of carbon in the soil of the tropical rainforest?
100 tonnes per hectare
134
What is a temperate grassland?
A savanna with an absence of trees and shrubs, dominated by grass.
135
How is a temperate grassland different to a tropical savanna?
Tropical savannas have trees and shrubs; temperate grasslands do not.
136
What is the dominant plant in a temperate grassland?
Grass.
137
Describe the location of temperate grasslands.
Found in the mid-latitudes in the centre of continents, between 40 to 60 degrees N of the Equator; although, there are some pockets of them in the southern hemisphere, where they lie between 30 and 40 degrees S.
138
Where are temperate grasslands found within continents?
Towards the centre of them.
139
In the Northern Hemisphere, at what latitudes are temperate grasslands found?
Between 40 and 60 degrees N.
140
In the Southern Hemisphere, at what latitudes can pockets of temperate grasslands be found?
30 and 40 degrees S.
141
How many main temperate grasslands are there?
4
142
Which temperate grassland is found in South Africa?
The Velds
143
Where are the Velds found?
South Africa
144
Which temperate grassland is found in Uruguay and Argentina?
The South American Pampas
145
In which 2 countries are the South American Pampas found?
Uruguay and Argentina
146
Which temperate grassland is found stretching from Ukraine eastwards to Mongolia?
The Eurasian Steppes
147
Between which 2 countries do the Eurasian Steppes span?
Ukraine eastwards to Mongolia
148
Which temperate grassland is found in North America?
The Plains
149
Where are the Plains found?
North America
150
What does the continentality of the temperate grasslands produce?
A high annual range in temperatures as there is no moderating influence from the sea.
151
What happens to the temperature of the temperate grasslands during the summer?
The ground warms up and it gets hot (around 20 degrees C).
152
What happens to the temperature of the temperate grasslands during the winter?
The ground cools down quickly and the temperature may fall below freezing.
153
What do clear skies produce in the climate of the temperate grasslands?
Great diurnal temperature change.
154
What is rainfall like in the temperate grasslands?
Low, annual precipitation is below 500mm.
155
What does lightening do in the temperate grasslands?
Cause fires which clear the ground and allow rare plants a chance to flourish.
156
What is the main factor preventing the growth of thick forest cover in the temperate grasslands?
The absence of rainfall.
157
What type of grasses dominate the temperate grasslands?
Perennial (short-lived) grasses such as feather grasses and tussock/tufted grasses.
158
What are the roots of plants like in the temperate grasslands?
Deep, extending to a depth of around 2m as they try to reach the water table.
159
What is species diversity like in the temperate grasslands?
Very low, with no more than 2 to 3 species of grazing mammals.
160
Give examples of animals which occupy the temperate grasslands.
Rabbits, gophers, antelopes, bison, kangaroo, hawks, eagles, wolves, coyotes
161
What is abundant in the soil of temperate grasslands.
Worms - 1m2 may contain 500 of them.
162
Why do worms play an important role in the carbon cycle of temperate grasslands?
They consume organic matter and excrete the waste.
163
In 10 years, what depth of soil may have passed through the gut of an earthworm in the temperate grasslands?
15cm
164
In total, how many gigatonnes of carbon is stored in the biomass and soil of temperate grasslands?
185 gigatonnes
165
Above ground in the temperate grasslands, how much carbon is stored per hectare?
2 to 10 tonnes.
166
In the temperate grasslands, where is most of the carbon found?
In the soil.
167
In the temperate grasslands, 2/3 of root biomass can be found within what depth of soil?
30cm
168
Each year, how much carbon is input into the atmosphere by deforestation?
1.6 gigatonnes
169
What percentage of global CO2 emissions comes from deforestation?
20%
170
Each year, how many hectares of forestry are lost to deforestation?
13 million hectares - the same size as Greece.
171
True or False? : All deforestation is anthropogenic.
False - Naturally it occurs through wildfires or overgrazing.
172
What is the effect of deforestation on photosynthesis?
It pretty much ceases until new plants begin to grow.
173
What is the effect of deforestation on respiration - both plant and animals?
Plant - ceases as the trees have gone.
| Animal - reduced as animals migrate out of their destroyed habitat.
174
In a virgin tropical forest, what is the input of carbon from photosynthesis?
30.4 tonnes per hectare per year
175
In a virgin tropical forest, what is the output of carbon from respiration?
24.5 tonnes per hectare per year
176
In a virgin tropical forest, what is the output of carbon from burning, decay of slash and soil erosion?
0 tonnes per hecatre per year
177
In tropical forest after 10 years of deforestation, what is the input of carbon from photosynthesis?
12.3 tonnes per hectare per year
178
In tropical forest after 10 years of deforestation, what is the output of carbon from respiration?
6.8 tonnes per hectare per year
179
In tropical forest after 10 years of deforestation, what is the output of carbon from burning, decay of slash and soil erosion?
18.3 tonnes per hectare per year
180
In a virgin tropical forest, what is the size of the carbon stored in above-ground biomass?
180 tonnes per hectare
181
In a virgin tropical forest, what is the size of the carbon stored in below-ground biomass?
64 tonnes per hectare
182
In a virgin tropical forest, what is the size of the carbon stored below ground/in the soil?
226 tonnes per hectare
183
In a tropical forest after 10 years of deforestation, what is the size of the carbon stored in above-ground biomass?
43 tonnes per hectare
184
In a tropical forest after 10 years of deforestation, what is the size of the carbon stored in below-ground biomass/roots?
12 tonnes per hectare
185
In a tropical forest after 10 years of deforestation, what is the size of the carbon stored below ground/in the soil?
150 tonnes per hectare
186
Why does soil erosion occur in a deforested tropical forest?
No interception allows for overland flow, which permanently transports carbon out of the system into rivers.
187
Summarise the effect deforestation has on a tropical forest.
It turns it from a carbon sink to a carbon source.
188
In the 1960s, what percentage of Indonesia was covered by rainforests?
80%
189
In Indonesia, what percentage of the original forest cover now remains?
50%
190
In Indonesia, what percentage of deforestation takes place on mineral soils?
70%
191
In Indonesia, what percentage of deforestation takes place on peatlands?
30%
192
What is used as a method to deforest Indonesia?
Slash-and-burn
193
True or False? : In 1997-1998, scientists believe that deforestation in Indonesia pumped more carbon into the atmosphere than that taken from the atmosphere by all of the organisms on the planet.
True.
194
Who is the world's 3rd largest emitter of greenhouse gases?
Indonesia, after the USA and China.
195
In Indonesia, what percentage of emissions come from deforestation?
85%
196
Which scheme is an example of climate change mitigation and sees financial incentives placed in developing countries for them to conserve their natural forestry?
The UN's REDD scheme (Reducing Emissions from Deforestation and forest Degradation).
197
In what year was the Forestry Commission established?
1919
198
Why was the Forestry Commission established?
Because Britain's woodlands had been depleted in the First World War.
199
In recent years, how has the Forestry Commission justified afforestation?
Carbon sequestration is of "pure international public good".
200
What is carbon offsetting?
The practice of compensating for your carbon dioxide emissions by funding an equivalent carbon store, i.e. planting a tree after you take a flight.
201
What is the largest source of carbon emissions within agriculture?
Enteric fermentation
202
What is enteric fermentation?
The digestive process of livestock which produces methane emissions.
203
What percentage of agricultural emissions comes from enteric fermentation?
39%
204
How much carbon is found in peatlands?
2,3000 gigatonnes
