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GEOGRAPHY - ELSS > 2.A - the carbon and water cycle in the Amazon basin > Flashcards

2.A - the carbon and water cycle in the Amazon basin Flashcards

1
Q

where is deforestation happening?

A
  • deforestation and degredation occurs in southern brazil/closer to major cities and centres of economy
  • most accessible part
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2
Q

what happens to surface run off without trees

A

surface run off increases by 27% without trees

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3
Q

why is the forest degraded?

A
  • selective logging
  • replacing w/ monoculture plantations and grazing land
  • not as good at storing carbon
  • 80% used for cattle
  • NO interception, surface run off, speed up lag time, gullying, soil erosion = ↓ capactiy of river
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4
Q

how much deforested land is used for cattle?

A

80%

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5
Q

what causes the rainforest’s huge input of rainfall?

A
  • equator = suns rays most concentrated
  • so there’s an excess of energy and it has to be re-distributed (tri-cellular model)
  • ITCZ shifts N and S with the seasons.
  • January = ITCZ south = bands of low pressure = rain
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6
Q

how will the climate in the amazon impact the stores and flows of the carbon/water cycle?

A
  • humid so atmosphere is a big store of water
  • biosphere, atmosphere and rivers = big stores
  • heat drives flows
  • lots of precipitation, evaporation and evapotranspiration
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7
Q

what happens in the ITCZ?

A
  • where air rises the most = more rain
  • moves between tropic of cancer and capricorn throughout the year
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8
Q

what is flux?

A

movement of CO2 from 1 part of the carbon cycle to another

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9
Q

how is the rainforest structured?

A
  • STRATIFIED STRUCTURE
    1. shrub layer (0-10m)
    2. lower tree canopy (20m)
    3. main canopy (20-40m)
    4. emergents (50m+)
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10
Q

what % of light reaches the ground floor?

A

less than 3%

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11
Q

what is GPP?

A

the amount of carbon taken out of the air/carbon that trees fix is known as the gross primary productivty (GPP)

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12
Q

what do tropical rainforests have all year round?

A

a positive carbon balance

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13
Q

what % of human emitted CO2 do tropical rainforests absorb?

A

25%

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14
Q

how much carbon is taken in per hectare?

A

200-300 carbon tonnes

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15
Q

why is transpiration such a crucial part of the water cycle?

A
  • clouds of water vapour forms above the rainforest canopy
  • these are carried away by wind in aerial rivers to drier parts of Brazil and falls as rain
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16
Q

what are the inputs in the rainforest water cycle?

A
  • precipitation is high in most months
  • the dense canopy intercepts up to 75% of the rainfall.
  • some of this water will be evaporated
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17
Q

what are the stores in the rainforest water cycle?

A
  • atmospheric moisture
  • interception storage
  • water in plant tissue
  • surface storage water in puddles
  • soil water
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18
Q

what are the flows in the rainforest water cycle?

A
  • evapotranspiration
  • precipitation
  • drip flow
  • stem flow
  • rainwater is transferred to the forest floor by a combination of drip flow and stem flow. drip tips help the tree to shed water from each leaf, and the rest trickles down branches and stems
  • most rainforest plants have very shallow roots that take rainwater and dissolved nutrients directly from decomposing leaf litter
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19
Q

what are the outputs in the rainforest water cycle?

A
  • water is lost by transpiration from pores in the leaves
  • evaporation from the soil
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20
Q

how does precipitation vary seasonally in the rainforest?

A
  • convectional rain falls all year round, though most areas experience at least one drier period
  • rainfall is highest in March (310 mm) and lowest in August (60mm)
  • high average annual rainfall (>2000mm) with no dry season
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21
Q

what % of precipitation is recycled?

A
  • between 50-60% of precipitation is recycled by evapotranspiration
  • water losses from the Amazon Basin result from river flow and export of atmospheric vapour to other regions
  • this loss is made up by an inward flux of moisture from the Atlantic Ocean
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22
Q

what is precipitation like in the rainforest? case study details

A
  • high avg annual rainfall (>2000 mm)
  • rainfall is fairly evenly distributed throughout the year, though short drier season occurs in some places
  • high intensity, convectional rainfall
  • interception by forest trees is high (around 75% of precipitation)
  • intercepted rainfall accounts for 25% of all evaporation
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23
Q

what are rates of evapotranspiration like and why?

A
  • high rates due to temperatures, abundant moisture and dense vegetation
  • strong evapotranspiration–precipitation feedback loops sustain high rainfall totals
  • around 50% of incoming rainfall is returned to the atmosphere by evapotranspiration
  • most evaporation is from intercepted moisture from leaf surfaces
  • moisture loss in transpiration is derived from the soil via the roots
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24
Q

what sustains rainfall?

A

strong evapotranspiration–precipitation feedback loops sustain high rainfall totals

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25
Q

where is moisture loss from?

A

moisture loss in transpiration from the soil via the roots

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26
Q

what influence does TEMPERATURE have on rainforest water STORES?

A
  • water is cycled continually between the land surface, forest trees and the atmosphere by evaporation, transpiration and precipitation
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27
Q

what influence does GEOLOGY have on rainforest water STORES?

A
  • impermeable catchments, e.g. large parts of the Amazon basin are an ancient shiled area, comprising impermeable crystalline rocks that have minimal water storage capacity
  • permeable and porous rocks such as limestone and sandstone store water
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28
Q

what influence does RELIEF have on rainforest water STORES?

A
  • widespead inundation across extensive floodplains (e.g. the Patanal) occurs annually, storing water for several months and slowing its movement into rivers
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29
Q

what influence does TEMPERATURE have on rainforest water FLOWS?

A
  • high temps throughout the year generate high rates of evapotranspiration.
  • convection is strong, leading to high atmospheric humidity, the development of thunderstorm clouds and intense precipitation
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30
Q

what influence does GEOLOGY have on rainforest water FLOWS?

A
  • impermeable rocks have minimal water storage capacity, resulting in rapid run off
  • permeable and porous rocks store rainwater and slow run off
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31
Q

what influence does RELIEF have on rainforest water FLOWS?

A
  • most of the Amazon basin comprises extensive lowland
  • in areas of gentle relief water moves across the surface (overland flow) or horizontally through the soil (throughflow) to streams and rivers
  • in the west the Andes create steep catchments w/ rapid runoff
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32
Q

which of the 3 factors influencing the water cycle is most significant?

A

GEOLOGY
- if the rock type is impermeable, it is always going to lead to surface run off and increased flood risk

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33
Q

what is the flood hydrograph?

A
  • shows pattern of precipitation and how flow of river responds to rainfall (the input)
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34
Q

based on its physical characteristics, is flood risk in the Amazon high or low?

A
  • naturally, in the Amazon (primary rainforest), flood risk is low and has a very large lag time
  • however, in deforested areas, there is high flood risk due to thin soils and impermeable rocks.
  • it reduces lag time, much steeper rising limb and higher peak discharge
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35
Q

what classifies as a rainforest?

A
  • there has to be at least 2000mm of rain annually
  • but mostly 3000-4000mm
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36
Q

what do canopy leaves do?

A
  • leaves in the canopy interrupt the rain by intercepting and slowing flow of water to the ground
  • the water continues its journey downwards by throughfall and stem flow
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37
Q

how do high levels of rainfall affect the soil?

A
  • the high levels of rainfall affect the soil by dissolving/leaching the nutrients
  • this means that the layer of organic/carbon content is quite thin
  • leaching leaves behind insoluble compounds = soil is reddish brown
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38
Q

why do rivers turn reddish-brown after rain?

A
  • leaching leaves behind insoluble compounds = soil is reddish brown
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39
Q

what happens if the canopy is removed?

A
  • removing the canopy, less rain is intercepted
  • this means it falls on the forest floor, washing away the organic layer and increasing surface run off
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40
Q

what happens if roads are built?

A
  • as roads are built more bare soil is revealed, meaning that ↑ run off and soil erosion even more
  • this causes water channels to get silted up, which can increase risk of flooding
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41
Q

how do palm oil trees create a positive feedback loop?

A
  • palm oil relies on there being no other plants, exposing more bare soil, increasing the amount of surface run off and leaching. however, it affects rainfall patterns
  • in a primary forest, some of the water is evapotranspired, which forms water vapour, clouds and rain.
  • reducing the primary forest means there’s less canopy cover, meaning the amount of evapotranspiration is reduced, therefore there are less clouds and therefore less rainfall.
  • this reduction in rainfall will reduce the rate of forest growth, thus acting as a positive feedback loop
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42
Q

deforestation rates

A
  • 1/5 of the primary forest has been degraded or destroyed since 1970
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43
Q

what happened in april 2014?

A
  • devastating floods occured on the Madeira River, the largest tributary of the Amazon river
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44
Q

why did the maderia drainage basin flood?

A
  • both heavy rainfall and deforestation have been recognised as contributing causes
  • however, there is also speculation that the Santo Antonio and Jirau Dams were also responsible
  • the 2 new dams located in the Brazilian state of Rondonia could have caused the extensive flooding see in parts of Bolivia and more recently Rondonia in Brazil
  • critics fear that the dams now prevent the natural flow of rivers and retain floodwaters for a longer time and in larger volumes
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45
Q

what were the impacts of the maderia drainage basin flood?

A
  • at Porto Velho the river reached record levels of 19m above normal
  • vast expanses of flood plain were inundated - 60 people died
  • 68,000 families were evacuated and there were outbreaks of cholera and leptospirosis
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46
Q

how do runoff rates change due to deforestation?

A
  • converting rainforest to grassland ↑ run off by a factor of 27
  • (50% of all rain falling on grassland goes directly into rivers)
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47
Q

what is rainfall like in UNDISTURBED RAINFOREST?

A
  • tends to be high w/ frequent and intense rainstorms
  • hot temps at the equator facilitate high rates of evapotranspiration from oceans, which is blown on land, condenses and cools, leading to convectional rainfall events
48
Q

what is interception like in UNDISTURBED RAINFOREST?

A
  • a portion of the rainfall is intercepted by trees and flora, as raindrops falling towards the ground are caught on their leaves
  • much of this intercepted water is evaporated directly back into the atmosphere meaning it never reaches the underlying land
49
Q

what is infiltration like in UNDISTURBED RAINFOREST?

A
  • infiltration should occur quickly because the trees provide leaf litter which maintains soil humus
  • the soil humus allows water to soak into it so it promotes infiltration
50
Q

what is evapotranspiration like in UNDISTURBED RAINFOREST?

A
  • much of water in soil is taken up by vegetation
  • this water is moved up through the vegetation by the xylem vessels and is lost back to the atmosphere as water vapour through the stomata via the process of transpiration
51
Q

what is atmospheric moisture like in UNDISTURBED RAINFOREST?

A
  • water that was evaporated from leaves following interception, transpired by vegetation or evaporated directly from the soil reenters the atmosphere as water vapour
  • helps to maintain humid conditions in tropical forests and when the moisture in the air condenses it will fall again as rain and is recycled.
52
Q

what is rainfall like in DISTURBED RAINFOREST?

A
  • atmospheric aridity leads to a decrease in rainfall as there is less water vapour in the air to condense into raindrops.
  • less water will infiltrate into soil = less moisture available for plants to take up through their roots
  • this can lead to water stress and vegetation die back
  • can be spatially variable
53
Q

what is interception like in DISTURBED RAINFOREST?

A
  • natural recycling of water = disrupted
  • when rain falls in areas where forest vegetation has been removed or replaced w/ crops, much less of the water is intercepted as there are fewer leaves, with a smaller combined SA to catch the raindrops = more reaches ground
54
Q

what is INFILTRATION like in DISTURBED RAINFOREST?

A
  • infiltration in deforested areas will be reduced because soil and hummus become diminished
  • the thin soils are washed away once they have lost the protection of the canopy
55
Q

what is evapotranspiration like in DISTURBED RAINFOREST?

A
  • rates of evapotranspiration from crops will be much lower than forests
  • crops = less dense, fewer plants to transpire and roots are shallower so theyre unable to access water deeper in soil
  • therefore instead of reentering the atmosphere, water will move towards the river
56
Q

what is atmospheric moisture like in DISTURBED RAINFOREST?

A
  • the ↓ in water being evaporated from leaves after interception, coupled with a decrease in transpiration, means that there is much less water vapour being returned to the atmosphere after a rainfall event
    = ↓ in humidity
  • air masses moving inland become arid as they pass over unvegetated areas
57
Q

decomposition

A
  • decomposition is an active process in tropical climates
  • decomposers such as fungi and bacteria thrive in the warm and wet conditions
  • this process releases carbon dioxide back to the atmosphere
58
Q

warm and wet tropical climate

A
  • ideal for plant growth
  • promotes the process of photosynthesis, which absorbs huge quantities of CO2 from the atmosphere
59
Q

rainforest plants and trees

A
  • wood is 50% carbon, so rainforest plants and trees are a huge carbon store
  • they are important “carbon sinks” in mitigating the effects of global warming
60
Q

why are trees so important in the Amazon carbon cycle?

A
  • forest trees dominate the biomass of the amazon and are the PRINCIPAL CARBON STORE
  • large forest trees typically store around 180 tonnes/ha
  • absorbing around 2.4 billion tonnes of CO2 a yr and releasing 1.7 billion tonnes through decompostion, the rainforest is a carbon sink of global importance
  • 60% of rainforest carbon is stored in the above ground biomass of tree stems, branches and leaves
61
Q

explain the role of photosynthesis as part of the carbon cycle

A
  • photosynthesis connects the rainforest to the atmosphere carbon stores
  • high temps, high rainfall and intense sunlight stimulate primary production
  • Amazonia alone accounts for 15-25% of all NPP in terrestrial ecosystems
62
Q

explain the role of decomposition as part of the carbon cycle

A
  • when trees are felled and left, they decompose
  • leaf litter and other organic matter accumulates temporarily at the soil surface and within rainforests
  • high temps and humid conditions promotes decomposition of organic litter by bacteria, fungi and other soil organisms
  • decomposition releases nutrients to the soil for immediate take up by root systems, and emits CO2 which is returned to the atmosphere
63
Q

how does the geology of the Amazon Basin affect the carbon stores?

A
  • the geology of the Amazon basin is dominated by ancient igneous and metamorphic rocks
  • carbonates are largely absent from the mineral composition of these rocks
  • however, in the western parts of the basin, close to the Andes, outcrops of limestone occur.
  • in the context of the slow carbon cycle they are significant regional carbon stores
64
Q

what is majority of deforestation for?

A

80% of deforestation in Amazon is cut down for grazing

65
Q

NPP in rainforest

A

NPP is high avg. 2500 grams/m2/yr

66
Q

forests are one of the…

A

largest terrestrian sinks of CO2

67
Q

what makes a forest a “primary” forest?

A

not affected by human activity

68
Q

how much carbon can primary forest store per hectare?

A

up to 3000

69
Q

what is selective logging and how much can it reduce the amount of carbon by?

A
  • only cutting down the largest tree
  • 50%
70
Q

what does logging reduce?

A

GPP

71
Q

what does partially logged TRF become and how?

A
  • a carbon SOURCE, not sink
  • dead trees and stumps are broken down by decomposers, releasing the carbon
72
Q

what is a secondary source?

A
  • one that regrows after initial deforestation
  • they expected to find that these will act as carbon sinks as plants/trees are growing
  • the impacts of logging don’t disappear that quickly
73
Q

what crop is being grown in plantations?

A

palm oil, thousands of hectares

74
Q

on the plantations, how much carbon is there?

A
  • in palm oil plantations, there is only about 30 tonnes of carbon per hectare - 10% of primary rainforest
  • palm oil plantations fix less than 50% the carbon of a primary TRF (less dense canopy)
75
Q

what will happen to plantations by 2025?

A
  • by 2025, there will be an additional 9 mill hectares of palm oil plantations, and for every hectare that is converted, 100 tonnes of carbon is released
76
Q

give a stat on how much carbon there is per hectare

A
  • the above ground carbon biomass in the rainforest is approx. 180 tonnes/ha
    (can be up to 400)
77
Q

how much carbon is stored in the biomass of primary forest and how does this compare to soya or pasture, which may replace it?

A
  • in the primary rainforest (unaffected), the biomass of trees represents about 60% of all carbon in the ecosystem
  • most of the remaining carbon is found in the soil as roots and dead organic material
  • crops and pasture contain only a small amount of carbon compared to forest trees
  • e.g. the biomass of grasslands in areas of former rainforest is 16.2 tonnes/ha and for soya cultivation it is just 2.7 tonnes/ha
78
Q

explain how deforestation affects soils in the Amazon

A
  • soils, depleted of carbon and exposed to strong sunlight, support fewer decomposer organisms, thus decrease the flow of carbon from the soil to the atmosphere
  • in rainforests, the principal store of plant nutrients such as calcium, potassium and magnesium is forest trees
  • rainforest soils contain only a small reservoir of essential nutrients and the forest is only sustained by a rapid nutrient cycle
  • deforestation destroys the main nutrient store - the forest trees - and removes the most nutrients from the ecosystem
  • nutrients no longer taken up by root systems of trees are washed out of soils by rainwater; and soils, without the protective cover of trees, are quickly eroded by run-off
79
Q

what is the impact of cattle ranching on the Amazon?

A
  • cattle ranching accounts for 80% of current deforestation throughout the Amazon
  • alone, the deforestation caused by cattle ranching is responsible for the release of 340 million tons of carbon to the atmosphere every year, equivalent to 3.4% of current global emissions.
  • soy developers then capitalise on the cattle ranchers and take over the land, pushing cattle ranching (and deforestation) towards new pioneer areas (feedback loop)
80
Q

how has deforestation affected water vapour?

A
  • water vapour is also considered a greenhouse gas
  • deforestation has decreased global vapour flows from land by 4%.
  • even this slight change can disrupt natural weather patterns and change current climate
81
Q

what is the quickest way to clear the forest and how does this affect the carbon cycle?

A
  • bulldozers
  • later the timber will be burned which releases stored carbon.
82
Q

how does the water cycle allow the carbon cycle to operate so fast in TRF?

A
  • increased precipitation = ideal growing conditions = increased photosynthesis and carbon storage
83
Q

how does the vegetation in a TRF link the 2 cycles and how does it change diurnally?

A
  • vegetation is a store of water = as it grows it stores more
  • account for the exchange of carbon between soils/plants/atmosphere through photosynthesis (only occurs in the day)/transpiration/respiration (releases carbon more due to day and night
  • intercept water to decrease run off
84
Q

how does deforestation (change in carbon store) in a TRF link the 2 cycles

A
  • alters levels of photosynthesis and less nutrients in soil = decreased chance of regrowing
  • less decomposers
  • ↓ carbon stores = ↓ water stores
  • ↓ evaporation = ↓ precipitation = ↓ run off and ↑ erosion of soils by water
    = ↓ fertility of soils and also ↓ photosynthesis = ↓ carbon stored
85
Q

what is shifting cultivation?

A
  • shifting cultivation is a traditional method of cultivation in tropical rainforests which involves the rotation of land rather than just the rotation of crops
  • it involves producing just enough food for survival and then moving onto new land
86
Q

what is the process of shifting cultivation?

A
  • small areas of forest are cleared to provide land for farming
  • the soil in this area stays fertile for around 10 yrs before farmers have to move again
  • this means a new area of forest needs to be cleared where soil is more fertile
  • after another several years, farmers will move again and this process keeps repeating
  • by the time theyre moving back to the first plot of land it will be fertile again and after 10 yrs they can move again
87
Q

how does shifting cultivation alter deforestation rates?

A
  • forest is cleared for crops until the soil is exhausted of nutrients or the site is overtaken by weeds and then moving on to clear more forest
  • it therefore increases deforestation rates as new areas of land are cleared after several years while the previous plot is recovering
  • however as a replacement for mass clearing of trees, it is better
88
Q

what are the positives of shifting cultivation?

A
  • it is more sustainable for the environment than other forms of deforestation as areas have time to regrow
  • the soil regains its fertility when farmers move on to new land
  • it is the traditional method that has been used by indigenous people for thousands of years
  • it is better for the environment as plants can regrow whilst farmers are elsewhere
89
Q

what are the limitations of shifting cultivation?

A
  • trees are cut down to make space for farming
  • could be multiple areas of land cut down at at time
  • it is more efficient for farmers to clear larger areas at a time
  • not utilised as much because people want economic growtha and dont care much about the environment
  • not great for economic progess - takes more time and planning
90
Q

what are the impacts of shifting cultivation on the carbon cycle?

A
  • shifting cultivation as an alternative method of deforestation creates less drastic change to the carbon cycle
  • amount of photosynthesis occurring in rainforest decreases less than the usual deforestation technique used
  • less carbon stores removed at one time
  • less carbon released into the atmosphere (only doing a small amount at a time)
91
Q

what are the impacts of shifting cultivation on the water cycle?

A
  • like the impact on carbon stores, shifting cultivaion has a less significant impact on the water cycle
  • when trees are removed, the amount of precipitation decreases and the surface run off increases
  • however this is less significant due to the fact only a few acres are cut down at a time the area can still remain quite sheltered
92
Q

how effective is shifting cultivation as a management strategy? POSITIVES

A

POSITIVES
- it provides an alternative method of living in the rainforest
- mitigates problem instead of adapting (prevent problem from occuring in the first place
- provides land for farming/living - income and growth
- only affects a small area initially

93
Q

how effective is shifting cultivation as a management strategy? NEGATIVES

A
  • doesnt replant any trees
  • soil becomes infertile for periods of time
  • loss of habitat
  • doesnt solve problem of deforestation
94
Q

how effective is shifting cultivation as a management strategy? CONCLUSION

A
  • shifting cultivation is effective as a small scale management strategy for living more sustainably in the rainforest
  • however it is less suitable for commercial farmers as only small areas are cleared at a time.
95
Q

what is afforestation?

A
  • afforestation involves planting trees in areas that havent recently had any tree cover, in order to create a forest
  • the type of land planted could include areas that have turned into desert through desertification, or places that have long been used for agriculture, or industrial areas
  • acts as a method to reduce atmospheric CO2
  • the forests created through afforestation also provide a habitat to local wildlife, create wind breaks and support soil hea;th
  • it reverses deforestation rates and is the only strategy to do so
96
Q

what is the impact of afforestation on the water cycle?

A
  • more flows of photosynthesis
  • improves topsoil, nitrogen is fixed at higher rates, which has also been shown to neutralize soil pH (reducing acidity in acid soils and alkaliity in alkaline soils)
  • improvement in soil fertility and promoting ecosystem productivity
  • allows for more recycling of water via transpiration and evaporation from leaves
  • reduces run off
97
Q

what is the impact of afforestation on the carbon cycle?

A
  • more carbon is able to be stored so it ultimately mitigates climate change
  • afforestation can reverse biodiverstity losses and provide carbon sinks, which are natural environments that are able to absorb carbon dioxide from the atmosphere
  • increases carbon storage in soils and trees overall
  • interception decreases levels of surface run-off
  • increases soil fertility and amount of photosynthesis so theres less soil erosion and more nutrients for decomposition
98
Q

example of afforestation

A
  • communities and governments choose to invest in afforestation projects, for example:
  • The Peugot-ONF Forest Carbon Sink project in Mato Grosso state of the Brazilian Amazon, has achieved significant ecological restoration and carbon sequestration results
  • the reforestation of the 2000 hectares of degraded cattle pasture has reached a level of biodiversoty similar to native forest and introduced a wide range of Amazonian species
  • a total of 394,400 metric tonnes of CO2 has already been sequestered by the project - the eqivalent of 85,000 cars taken off the road for a year.
99
Q

what are the disadvantages of afforestation?

A
  • afforestation depends on the quality of the soil - if a hard, impenetrable surface to the soil has formed, it needs to be broken up and the soil aerated
  • trees also have to suit the local environment. the most significant risk is the use of non-local tree species
  • these trees may be fast growers that will draw down carbon, but may use more water than the area has available
  • you have to consider prevailing winds and the direction of sunlight in different seasons
  • it takes around 120 yrs for topsoil biomass and composition of species to recover.
  • not as good for wildlife as primary forests
100
Q

what are the benefits of afforestation?

A
  • improves soil health and quality
  • reverse land degredation
  • halts land desertification
  • provides clean water through an intensified water cycle
  • improve water levels of the groundwater, thus reducing flooding
  • creates income generation
101
Q

is afforestation effective?

A
  • overall, an effective way of controlling deforestation rates and reducing greenhouse gas emissions in the SHORT TERM
  • however, trees take time to grow and reach optimal photosynthesis levels
  • additionally, it heavily relies on funding (NGOs, Govts, global firms)
  • it is hard to implement on a large scale with only some areas being replanted
  • in the long run it would have been more beneficial to have stricter and upheld rules on deforestation
  • although afforestation is considered to be one of the most “natural” and simple ways to reduce carbon dioxide emissions
  • cost
102
Q

what is diversification of agriculture?

A

there are 2 main diversification of agriculture methods used:
1. Dark soils
2. agroforestry

103
Q

how are dark soils used in diversification of agriculture?

A
  • the idea explores the use of human engineered soils
  • these so called dark soil are made from inputs of charcoal, waste and human manure
  • scientists are currently investigating these new soils, if they can be successfully recreated they would allow intensive and permanent cultivatrion which would drastically reduce deforestation and carbon emissions
104
Q

how will dark soils used in diversification of agriculture slow the rate of deforestation?

A
  • the charcoal in the new soils attracts micro-organisms and fungo and allows the soil to retain its fertility long term
  • this means that one area can be used to grow crops for multiple seasons and therefore limits the amount of open land farmers need to grow crops and decreases deforestation.
105
Q

what is agroforestry?

A
  • agroforestry is the deliberate culture of plant species interacting ecologically or economically with seasonal cultivations and/or animal breeding
  • originally people’s lifestyle in the Ecudorian Amazon was nomadic. their lifestyle depended on hunting and food gathering but they were also practicing slash-and-burn agriculture
  • however in recent years when farmers began to settle they have turned to agroforestry
106
Q

how does agroforestry limit deforestation rates?

A
  • agroforestry mimicks nature, using a “polyculture” of trees to regenerate land and restore biodiversity whilst also producing crops.
  • ultimately, it creates a healthy ecosystem and spares farmers the choice between nature and livelihoods
  • overall it is a sustainable method of farming which artificially replicates the rainforest and therefore decreases deforestation as it provides a way for farmers to use land without having to clear areas using slash and burn techniques
107
Q

how will agroforestry affect the water cycle?

A
  • using agroforestry instead of slash and burn will mean less areas of open forest and therefore increase interception
  • this will in turn increase lag time and decrease peak flow, reducing the flood risk in the local area
  • additionally, agroforestry will lead to increase rainfall being recyled and put back into the atmosphere by transpiration
108
Q

how will dark soils affect the water cycle?

A
  • dark soils may have a larger moisture storing capacity and therefore also decrease surface runoff
109
Q

how will agroforestry/dark soils affect the carbon cycle?

A
  • the use of agroforestry and dark soils means the overall amount of deforestation that has to occur for farmers to make a living out of agriculture decreases
  • therefore, this decreases the amount of CO2 released into the atmospher when areas of the rainforest are felled to make clearing
  • additionally the volume of CO2 absorbed by photosynthesis will increase, as will the volume of oxygen produced.
110
Q

how effective could agroforestry/dark soils be?

A
  • these could be very successful in the long term as they would severly decrease the volume of trees that could be felled for farming
  • however, it could be argued that many farmers may just continue to farm using current methods due to the difficulty implementing dark soils and agroforestry
  • furthermore, agroforestry could be considered less profitable and therefore may not be as effective in attracting people to operate in this way
  • changing land ownership is a barrier = farmers have to stay on a specific patch of land for it to work
111
Q

what is the REDD scheme?

A
  • the UN’s “Reducing Emissions from Deforestation and Degredation” (REDD) scheme provides payment to the Surui indigenous group for protecting the rainforest and abandoning loggin
  • it is a market-based approach involving the granting of carbon credits to the Surui
  • these credits can be purchased by international companies who have exceeded their annual carbon emission quotas
  • for example in 2013 Natura, a large TNC, purchased 120,000 tonnes of carbon credits from the Surui
  • this was the first carbon credit sale by indigenous people in Amazonia
112
Q

how does the REDD scheme alter deforestation rates?

A
  • it dramatically reduced deforestation within the territory during its first five years of operation (2009-2014), but was suspended in 2018 after the discovery of large gold deposits in the territory sparked a surge in deforestation (suggets its long term impermanence)
  • a large limitation of this scheme is “leakage”: a reduction in carbon emissions in one area that results in increased emissions in another
  • a classic example is where curbing clearfelling in one region of forest drives farmers to clearfell in another
113
Q

what is the REDD scheme impact on the water cycle?

A
  • REDD schemes prevent deforestation in the Amazon, so therefore limit the impacts felt by the water cycle, such as increased run off and flood risk, and decreased interception and transpiration (leading to droughts)
  • this means the water cycle is ultimately unaffected as the forest is left untouched
  • therefore, habitats remain stable, and social impacts from extreme weather/natural hazards are prevented
  • however, the potential impermanence and difficulty of monitoring this strategy may mean that deforestation will occur in these areas in the future, so the water cycle will be affected.
114
Q

what is the REDD scheme impact on the carbon cycle?

A
  • before being suspended, the project generated 300,000 carbon offsets certified under the Verified Carbon Standard (VCS)
  • this is equal to removing 64,000 cars from the road for a year
  • this helps to meet the global imperative to sequester carbon from the atmosphere, where it acts as a greenhouse gas, enhancing the greenhouse ffect and contributing to global climate change
  • reducing deforestation means primary forest remains: storing 400 tonnes of carbon per hectare
  • there is less combustion and felling of forest so stored carbon is not released and the trees can continure photosynthesising and contributing to the Amazon’s carbon sink
115
Q

what are the positives of the REDD scheme?

A
  • the surui used proceeds from offset sales to finance 6 sustainable community development initiatives that generate income and support traditional practices, such as the harvesting of medicinal plants.
  • this enables long term socio-economic development which is not reliant on deforestation in the area by putting even more value on the land: but this is on a local scale
  • large scale in terms of carbon offsetting; it removes vast amounts of carbon from the atmosphere by sequestration
  • relatively cost-effective: offsets cost less that $50 per tonne of CO2 (carbon capture costs $250-650)
116
Q

what are the limitations of the REDD scheme?

A
  • carbon calculations may be inaccurate and they have a high degree of uncertainty
  • difficult to monitor accurately and reliably
  • you cant tell if it would have been left as primary forest anyway (no extra carbon is being sequestered)
  • LEAKAGE - deforestation will increase elsewhere
  • imbalance of the water cycle can cause flooding downstream and felling elsewhere will affect the Amazon’s ability to sequester the maximum amount of carbon
  • permanence: the long term viability of reduced emissions from a REDD project is heavily dependent on the forested area’s vulnerability to deforestation and/or degredation

GEOGRAPHY - ELSS (9 decks)

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