amazon case study 
A systems approach
The global water cycle is a closed system. There is no loss or gain in water as it is cycled between the major stores. However, the Amazon rainforest is an open system – it receives inputs of water and carbon from outside the system and there are outputs from the system. However, the dynamic equilibrium of these stores are being disrupted by humans.
Changes/ threts to the Amazon
The size of the amazon has been decreasing by 0.3% every year since 2000. Selective logging of mahogany trees damages nabouring trees leading to open gaps exposed to sunlight and wind meaning they dry out quicker and can lead to more frequent wild fires. When forests are burnt between 30 and 60% of the carbon is emmited directly into the atmosphere. Agreculture is responcible for around 80% of tropical forest deforestation
Belo Monte Dam is a hydroelectric dam which floods over 640km squared of the rainforest. It will not only damage the lives of thousands of people, indigenous people who rely on the river will be forced to relocate. It will leave populations with ought fish and water and force many people into jobs such as logging and cattle ranches. But it will also dramatically damage the rainforest with the flooding. It will lead to the extinction of at least 10 species and the mosquitos which carry diseases like malaria will be able to bread uncontrollably . The decomposing vegetation from the flooded forest would release methane which is 25x more potent than C02.
click to edit
solutions
In COP 26 Brazil commited to end deforestation by 2030
Over half of the Brazilian Amazon is now part of national parks or indijenous lands. For example, the Para Rainforest reserve preserves 15 million ha of rainforest.
Enrichment of degraded forests using native speacies is increasing
Brazil refused to source cattle from ranches within 10km od deorestation. This foreced the cattle industry to improve its practises
The Brazilian space agency have launched a saterlight which moneters change in forest in real time, producing a report on deforestation hotsports for law inforcement every 2 weeks. It is estimated that this has prevented the deforestation of 59000 square km of rainforest between 2007 and 2011
fun facts lolz
The basin is the world's largest rainforest and one of the most biodiverse its 300 billion trees and 15,000 species star 1/5 of all the carbon in the planets biomass.
the amazon in the carbon cycle.
Productivity of the rainforest has increased due to the increased co2 in the atmosphere. However, the amazon is loosing its capability to absorb co2 from the atmosphere, halfing since the 1090s.
The Amazon is estimated to store between 80 and 120 billion tons of carbon.
the amazon as a negative system- rainforests have seen rising productivity due to increased C02 concentrations in the atmosphere. The higher the productivity, the more growth, the more carbon taken out of the atmosphere.
the amazon in the water cycle
the average discharge from the amazon into the atlantic ocean makes 15% of fresh water entering the oceans each day
Average rainfall across the whole amazon basin is aproxamatly 2,300mm anually but up to half of his may never reach the group. It is intersepted by the forrest canopy to then be evaporated. Of the rainfall that is evaporated back to the atmosphere, nearly half of it falls as rain again over the amazon. Only about 30% of the rainfall actually reaches the sea.
affects of change
The particals released from burning creates condensation nuclei which cater vapour clings to. This creates many but small clouds with not enough water to precipitate, meaning there is less local rain
Brazil is the worlds 4th largest climate polluter with 75% of their greenhouse gas emissions attributed to deforestation and land use change
a 2 dagree temperiture rise above pre industrial levels will see 20-40% of the Amazon die offf within 100 years
The capacity of thr Amazon rainforest to absorb carbon is declining. In the 1990s it drew down over 2 billion tons of C02 overy years but in 2015 it decreased to 1 bllion.
the newly deforested areas are dark in coulder with a low albedo. This means that the ground will absorb the suns radiation, making the area hotter rather than reflecting it.
Climate change
It is predicted that by 2050, temperitures in the amazon will increase by 2-3 dagrees. Some plant species in the Amazon are limated by their tollarance to temperiture change, drought and seasonality. Droughts and high temperitures are also playing a part in killing the trees. A 4 dagree temperiture rise would see 85% of the amazon die off in the next 100 years.
Selective logging is less damaging to the forest than clearing huge spaces. If only a few trees are taken from each area the forest structure is kept and the soil will not be exposed. This means the forest is able to regenerate, so the impact on the carbon and water cycle is small.
Replanting- new trees are planted to replace the ones that are cut down. For example, Peru plans on restore 3.2million hecters of forest by 2020.
Presenty a carbon sink, absorbing 35% of the worlds annual carbon emmisions.
It produces 20% of the worlds oxygen
the exess carbon in the atmosphere causes trees to have a growth spurt, they grow quickly and therfore die quicker.. This reduces the capacity of the rainforest to absorb energy
The amazon as a positive system- Forests pull in large amounts of water vapor from surrounding regions and from nearby bodies of water. As the vapor condenses into rain, the local atmospheric pressure drops. Which sucks in more water vapor from outside the forest. Which repeats the process. Creating a positive feedback loop