2.2.a Amazon TRF

Precipitation

• Dominated by hardwood trees
• Average annual rainfall over 2000mm
• Rainfall evenly distributed throughout the year
• High-intensity convectional rainfall
• Trees intercept 10% of rainfall

Evapotranspiration

• High rates due to high volumes of precipitation, humidity and dense vegetation
• Strong precipitation-evapotranspiration feedback loop
• 50% of rainfall is returned in this way

Run-off

• Rapid run-off due to high, intense rainfall
• Well drained soils
• River discharge peaks for 2 months per year

Atmosphere

• High temperature enables the atmosphere to store large quantities of water
• Absolute humidity is high
• Relative humidity is also high

Soil/groundwater

• Abundant rainfall
• Deep tropical soils
• Significant amount of storage

Vegetation

• Trees store water for respiration
• Released via transpiration

• Humid environment is perfect for vegetation growth
• NPP = 2.5kg per metre squared per year
• Biomass = 400-700 tonnes per hectare
• The Amazon absorbs around 2.4 billion tonnes of carbon every year
• Rapid exchange between different stores within the carbon store
• Conditions cause quick rates of decomposition releasing carbon into the atmosphere
• Leached and acidic soils have a limited amount of nutrients as biomass takes up all available nutrients extremely quickly

Geology

• Impermeable catchments due to ancient crystalline rock structure with a low water storage capability. This causes rapid run-off
• Permeable and porous rocks such as limestone can store some rainwater. This results in a slower run-off

Relief (Slope)

• Most of the Amazon is extensive lowlands
• Overland flow when in areas with gentle relief
• Throughflow into streams and rivers
• The Andes to the West creates steep catchments creating a fast run-off
• Extensive floodplains caused by flat land

Temperature

• Leads to high amounts of evapotranspiration
• High amounts of convection leading to high atmospheric humidity
• More intense precipitation and thunderstorms

• Forest tress dominate biomass and are the largest of the carbon stores
• Approximately 100 billion tonnes or carbon is stored in the Amazon
• Absorbes 2.4 billion tonnes of carbon every year and releases 1.7 billion tonnes through decomposition
• Photosynthesis locks carbon in from the atmosphere
• Leaf litter and dead organic matter accumulates in the Amazon's soils
• High temperatures lead to rapid decomposition by saprobionts such as bacteria

• Deforestation at a rate of 17,500 km squared per year between 1970 and 2013
• Since 1970, 20% of the natural Amazon has been destroyed or degraded
• Rates of deforestation have decreased in recent years
• April 2014 - Devestating floods along the madeira river
  • 19.68m above normal level in some places
  • 68,000 evacuated
  • 60 dead
  • Outbreaks of cholera
  • Due to humans removing trees north of the flooding decreasing the stores of water and increasing run-off. Effects increased due to steep slopes of the Andes
• Changes on both local and national scale
• Rainforest to grasslands increased run-off by a factor of 27
• Trees are crucial for extracting moisture from soil, intercepting rain and releasing water into the atmosphere through evapotranspiration
• Predictions say that precipitation will decrease by 20% regionally drying out the rainforest into grasslands
• This will cause massive implications downwind too

• In unaffected rainforest, tree biomass represents 60% of the carbon stored
• Deforestation is exhausting this store
• Deforestation is reducing the inputs of carbon into litter and soil impacting the trees around it
• Land without the trees supports other organisms so other species migrate to areas with more trees increasing competition between species
• Soils without the protective covering from trees are quickly eroded away by aeolian processes

• Aims to develop 1000km squared of commercial timber on government-owned deforested land
• 20 million fast-growing hardwood seeds
• 4000 smallholdings
• 25 year period
• Financial assistance is provided to the smallholdings for preperation, planting and maintainance
• Tree nurseries provide the with the seedlings
• Timber will be exported along the river
• Monoculture - Less biodiversity
• Sustainable and sequesters carbon into the trees and soil
• Reduced the amount of CO2 in the atmosphere
• Re-establishes water and carbon cycles
• Reduces run-off

• Prevent illegal logging
• Reforest degraded ares from the last 40 years
• Plant local seedlings in deforested areas
• Species that are chosen provide them with timber, food and a sustainable source of income
• First to join the UN's REDD scheme
• This gives them payment as companies who are more carbon efficient recieve carbon credits allowing them to buy off the Surui tribe
• In 2013, Natura, Latin America's largest cosmetics seller, purchased 120,000 tonnes of carbon credits from the tribe

• Farming is the main cause of deforestation
• Low fertility of soil has caused the farming cultivation to not be sustainable
• After a few years, farmers move as the land is no longer suitable fo the cattle and crops
• Large parts of the rainforest are set on fire during slash and burn causing the land to be degraded very quickly
• Soil fertility can be maintained by not having a monoculture
• Rotational cropping also maintains soil fertility
• Dark soils made from charcoal can be used to attract microorganisms resparking the carbon cycle