The Amazon

Question 1

Location & key characteristics

Answer 1

• located in South America
• 60% of the 6,7 million square km rainforest is in Brazil, the other 40% is shared between 8 other nations: Bolivia, Columbia, Guyana, Peru, Suriname, Venezuela and french guinana
• it has 300 billion trees and stores 1/5th of all carbon in the planet’s biomass, also accounting for 30-50% of global photosynthesis
• wide range of plants: myrtle, laurel, palm and acacia
• rainforests hold most of their nutrients in their live vegetation, not in the soil. Their soils do maintain nutrients very well which means that exiting nutrients leech out being carried away as it percolates through the soil

Question 2

What happen to the water

Answer 2

• the average rainfall in the amazon basin is 3000mm per year, wit the greatest rainfall coming between December-May and temperatures average 28oc, resulting in a very humid climate.
• high humidity and unstable weather results in heavy rainfall most days with 25% of the rainfall being evaporated due to humidity, a lot of water vapour is from transpiration from the trees
• 75% of this total rainfall is intercepted by the trees and then to the ground through stem flow -> of the 75% half is used by plants and eventually returned to the atmosphere through evapotranspiration -> other half infiltrates the soil
• stored temporarily on the ground surface or flowing overland to river channels (runoff)

Question 3

What are the main drivers of change to the Amazon water cycle

Answer 3

• the amazon rainforest has lost approximately 17% of its primary rainforest in the last 50 years
• 80% due to cattle ranching mainly for economic growth as they export a lot of meat across the world (mainly SA&NA)
• other reasons include logging, mining and for housing to keep up with population growth
• between 200 and 2007, 19386km squared was being destroyed per year
• in Brazil, 2022 was the greatest amount of deforestation ever as a result of shortages in the economy of things like paper as a result of Covid; compared to 2023 where deforestation was down by 50% as a result of greater environmental awareness and concern.
• several factors contributed to change, both human&physical: Deforestation, climate change, land use changes, forest degradation, river damming, agricultural practices, feedback mechanisms, extreme events and global atmospheric circulation

Question 4

Processes contributing to the change in the rainforest water cycle: deforestation

Answer 4

• clearing large areas of the rainforest for agriculture, logging, and other purposes reduces the forests transpiration and evaporation, affecting local and regional precipitation patterns
• reduced vegetation cover can lead to decreased moisture recycling within the ecosystem

Question 5

Processes contributing to the change in the rainforest water cycle: climate change

Answer 5

• altered global climate patterns, including rising temperatures and changing precipitation regimes, can influence the intensity and frequency of rainfall in the Amazon
• changes in climate may lead to more prolonged dry seasons and altered storm patterns

Question 6

Processes contributing to the change in the rainforest water cycle: land use changes

Answer 6

• conversion of natural vegetation to urban areas, agricultural, or pastureland can disrupt the natural water cycle and reduce the forests ability to absorb and release water
• changes i land use can impact the overall balance of evapotranspiration and precipitation

Question 7

Processes contributing to the change in the rainforest water cycle: forest degradation

Answer 7

• selective logging, wildfires, and other forms of rest degradation can disrupt the integrity of the rainforest, impacting its ability to maintain a healthy water cycle
• degradation reduces the forests resilience to environmental changes

Question 8

Processes contributing to the change in the rainforest water cycle: river damming

Answer 8

• construction of dams for hydroelectric projects alters the flow of rivers, affecting sediment transport, nutrient cycling, and the overall hydrological balance of the region
• dam construction can lead to changes in river dynamic and influence local weather patterns

Question 9

Processes contributing to the change in the rainforest water cycle: agricultural practices

Answer 9

• agricultural activities, such as large-scale farming and cattle ranching, can lead to changes in land cover and runoff patterns, impacting the natural flow of water within the ecosystem
• house of irrigation can also modify local hydrological conditions

Question 10

Processes contributing to the change in the rainforest water cycle: feedback mechanisms

Answer 10

• changes in the water cycle may trigger feedback mechanisms, creating self-reinforcing cycles of environmental change. For example, increased temperatures can lead to more evaporation, further influencing precipitation patterns

Question 11

Processes contributing to the change in the rainforest water cycle: extreme events

Answer 11

• increasing frequency and intensity of extreme weather events such as droughts and intense storms, ca have significant impacts on the Amazon water cycle, affecting river levels, groundwater recharge, and overall ecosystem health

Question 12

Processes contributing to the change in the rainforest water cycle: global atmospheric changes

Answer 12

• alterations in global atmospheric circulation patterns, such as El Niño and La Niña events, can influence regional climate conditions, impacting the Amazons water cycle

Question 13

Why do topical rainforests play a vital part in the carbon cycle

Answer 13

• tropical rainforests play a crucial role in the carbon cycle because they act as significant carbon sinks (wood is about 50% carbon). The dense vegetation in these forests absorbs and stores large amounts of carbon dioxide through photosynthesis. This stored carbon is then released during respiration, but a substantial portion remains sequestered in the trees and soil. The preservation of these rainforests helps mitigate the effects of climate change by reducing atmospheric carbon dioxide levels
• the amazon is estimated to store between 80 and 120 billion tonnes
• rainforests around the globe act as carbon sinks of around 1-3gtC/year
• biomass of these rainforests have been increasing due to increase sequestration of CO2 concentrations - this acts as an Edgar I’ve feedback loop
• it is assured that increased CO2 levels encourages biomass growth. However, although rainforests are growing quicker, they are dying much sooner

Question 14

Physical impacts on the carbon cycle

Answer 14

• the arm and wet tropical climate is ideal for plant growth. This promotes the process of photosynthesis. This absorbs huge quantities of carbon dioxide from the atmosphere. In return, the rainforest emit oxygen. Wood is about 50% carbon, so rainforests themselves are a huge store as well as a sink in mitigating the effects of global warming
• respiration by plants, trees and the many animals return CO2 back to the atmosphere. Decomposition is an active process. Bacteria and fungi thrive in the warm, wet conditions. This then releases CO2 back into the atmosphere. Some carbon may be stored within the soil or dissolved and then removed by streams as an output from the rainforest system

Question 15

Human impacts on the carbon cycle

Answer 15

• slash&burn -> cheap, quick and effective. The blackened stumps and ground surface is carbonised wood. Apart from what is stored in this burnt debris, the rest of the carbon has been emitted into the atmosphere as CO2; when burnt for land clearance between 30-60% of carbon is immediately released into the atmosphere. In a typical year the Amazon absorbs 2.2bn tonnes, by 2015 this had decreased to just 1bn tonnes
• photosynthesis ceases until new plant growth begins. This is by far the most significant impact of deforestation on the carbon cycle. Plant and animal respiration drop to almost zero. Rain washes ash into the ground. This increases the carbon content in the soil. In heavy rainfall, carbon in runoff may increase too. Decomposes will be largely absent from this environment
• HOWEVER: replacing rainforest with alternate uses, such as crops and pasture, reintroduces stores and flows, although operating at much less effective levels

Question 16

How has climate change impacts the vegetation, soil and rivers within the Amazon rainforest

Answer 16

• rising temperatures and altered precipitation patterns affect vegetation, causing shifts in plant distribution and potentially leading to species loss. Changes in rainfall contribute to droughts and floods, impacting soil quality and nutrient availability. River systems in the Amazon are also affected, with altered water levels and increased frequency of extreme events. These disruptions can have cascading effects on the delicate balance of the ecosystem threatening biodiversity and the overall health of the rainforest.
• when forests and cleared and burnt, 30-60% is lost to the atmosphere; unturned vegetation decays and is lost within 10 yers. The soil fungi and bacteria used to recycle the dead vegetation dies off. Changes in total precipitation, extreme rainfall events and seasonality may lead to an overall reduction in river discharge causing an increase in silt washed into the rivers which could disrupt river transport routes. This leads to flash flooding, therefore destroys freshwater ecosystems; this could remove a source of protein and income to local inhabitants, this destroy water supply which fulfils the need of Amazonian people

Question 17

What is mitigation in climate change

Answer 17

• in the context of climate change, mitigation refers to the efforts and strategies aimed at reducing or preventing the emission of greenhouse gases to lessen the impact on the earths climate. This involves measures such as transitioning to renewable energy sources, improving energy efficiency, afforestation, and adopting sustainable practices across various sectors. Mitigation actions are essential to slow down the rate of climate change and minimise its adverse effects on the planet

Question 18

Local policies to mitigate climate change in the Amazon

Answer 18

• forest conservation and restoration: implementing policies to protect existing forests, prevent deforestation, and promote reforestation efforts to enhance carbon sequestration
• sustainable land use planning: enforcing regulations that promote sustainable agricultural practices and land-use planning to minimise the environmental impact on the rainforest
• indigenous land rights: recognising and respecting the land rights of indigenous communities, as they often play a crucial role in sustainable land management and conservation
• renewable energy promotion: encouraging the use of lean and renewable energy sources to reduce dependence on fossil fuels, thereby decreasing greenhouse gas emissions
• monitoring and enforcement: strengthening and monitoring mechanisms and law enforcement to prevent illegal logging, mining, and other activities contributing to deforestation and environment degradation
• education and awareness programs: implementing programs o educate local communities about sustainable practices, the importance of biodiversity, and the role they play in mitigating climate change
• research and innovation: supporting research initiatives to develop and implement innovative technologies and practices that contribute to slim are change mitigation in the region

Question 19

National agreements

Answer 19

• Brazil’s national plan o climate change: a comprehensive strategy outlining Brazil’s efforts to reduce GHG emissions, combat deforestation, and promote sustainable development in the Amazon
• Forest Code (Brazil): legislation governing land use and preservation, including provisions for maintaining a percentage of forest cover on private properties, contributing to the protection of the Amazon rainforest

Question 20

International agreements

Answer 20

• Paris agreement: a global accord signed by nations including those with significant portions of the Amazon, aiming to limit global temperature increase well below 2oc. Countries commit to reducing emissions and enhancing resilience to climate change impacts
• reducing emissions from deforestation and forest degradation (REDD+): an initiative under the United Nations framework convention on climate change (UNFCCC) that provides financial incentives to developing countries countries, including those with Amazon territories, for reducing deforestation and promoting sustainable land use
• Amazon cooperation treaty organisation (ACTO): an intergovernmental organisation involving Amazonian countries, working towards sustainable development and environmental protection in the region. While not exclusively focused o climate change, it addresses related issues
• Norwegian international climate and forest initiative (NICFI): Norway has committed funds to support Amazon countries efforts to reduce deforestation and promote sustainable development through agreements with individual nations

Question 21

mitigation - reforestation

Answer 21

• in addition to avoiding deforestation, environmental change can also be mitigated by planting trees in areas without trees. Atmospheric carbon is sequestered by being incorporated into tree biomass, and depending on whether the wood is harvested and what products are derived, the carbon i maintained out of the atmosphere for variable amounts of time
• sustainable forest management has often been suggested as a form of carbon sequestration because carbon in wood that is converted to long-lived wood products, such as fine hardwood furniture and construction timber remains out of atmosphere while the trees in the harvested location re-grow and accumulate more carbon
• seedlings of native spices can also be grown in. Local nursery and planted in degraded forests. These results could enhance the reforestation efforts and encourage the growth of native species including threatened ones in order to restore a high level of biodiversity