Amazon rainforest

• Location:


  South America
• How many countries does it span across?

  - 9= Brazil, Peru, Bolivia, Ecuador, Colombia, Venezuela, Guyana, Suriname & French Giana

  - 60%= Brazil
• Facts about the Amazon:

  - World's largest rainforest- covers 5.5 million km2

  - 300 billion trees

  - 15,000 species (rainforest= 50% of species in world)

  - Trees/species store 1/5 of carbon in Earth's biomass

  - 2000-2007= 19,386km2 were destroyed per year
• Amazon's water cycle:


  - Wet climate= Lots of evaporation over Atlantic Ocean (gets blown to Amazon)

  - Causes very high rainfall (average annual 2000mm)

  - 48% of precipitation falls as convectional rainfall

  - Warm temps.= high evaporation, incr. precipitation

  - Dense canopy= high interception, so less water flows into rivers

  - Species= adapted to high humidity & frequent rainfall

  - Has many tributaries (The Rio Negro)
• Human activities that impacted Amazon's water cycle:

  - Deforestation (17% lost in last 50 yrs) for logging, mining farming & cattle ranching (80%)

  - Deforested areas= lack of tree canopy to intercept rainfall= more water reaches ground,

  - Not all water infiltrates so moves to rivers as surface runoff= risk of flooding & increases soil erosion

  - Rate of evapotranspiration decreased= less water vapour reaches atmosphere

  - Fewer clouds form & rainfall is reduced= droughts

  - E.g. Sau Paulo, Brazil-worst drought in 80 years (reservoirs empty & used emergency water supplies)

  -Slash & burn techniques:

  - Reduces the soil's ability to retain humidity from the top layer down to a depth of 1 metre

  - Accelerates sudden evaporation of water previously retained in forest canopy

  - Reduces pores within soil= increased surface runoff, more erosion & minerals in river/lakes are drained
• Amazon's carbon cycle:


  - Estimated to store 80-120 billion tons of carbon

  - Lots stored in soil & vegetation= carbon sink

  - Incr. concentration of CO2 in atmosphere= increased productivity (plants able to absorb more CO2 for photosynthesis)

  - But, this growth spurt isn't ideal= trees are growing quicker, so are dying younger (short plant life-span)

  - May not be able rely on the Amazon to be such an effective carbon sink in the future
• Human activities that impacted Amazon's carbon cycle- Climate Change:


  - Combustion of fossil fuels (transport & industry) & deforestation= vast incr. in atmospheric CO2= increase in GHG leading to global warming

  - Resulted in growth spurt in trees= live faster & die younger

  - 2015 study shows that Amazon is losing its capacity to absorb CO2 from atmosphere

  - Any moisture that evaporates from deforested areas only form shallow, cumulous clouds & reduces rainfall

  - Salts & organic fibres are also transpired (with water) which assist in cloud & rain formation

  - However, deforestation inhibits the formation of clouds & reduces rainfall
• Human activities that impacted Amazon's carbon cycle- Vegetation Change:


  - Replacing trees with crops reduces amount of CO2 absorbed= increased CO2 in atmosphere

  - Rainforests affect the reflectivity of a surface (albedo) by absorbing heat from solar energy (rainforests absorb 11% more than pastureland)

  - So removing trees increases albedo & also temp.
• Climate Change:


  - By 2050 temp. will raise by 2-3 degrees

  - Species have adapted to mosit conditions of the Amazon- many may die in dry conditions

  - Frequent & long periods of droughts=exctincion of some species

  - Droughts- wildfires (destroy large areas of forest & release lots of CO2 into atmosphere)

  - Scientists believe a 4 degree rise will kill 85% of rainforest= increased carbon released into atmosphere as dead material decomposes & less trees to absorb it for photosynthesis

  - Less evaporation= less precipitation
• National & International Agreements- ACTO:

  Amazon Cooperative Treaty Organisation (ACTO):

  - Involves 8 member countries= promoting sustainable development

  - Aim: to reverse the loss of forest cover worldwide through sustainable forest management (such as protection, afforestation & reforestation) & to monitor & prevent illegal logging
• National & International Agreements- TARAPOTO Agreement:


  - Began in 1995

  - 8 countries involved in managing the forest sustainably (at management & national level)

  National Level:

  - Investment in research, education & technology

  - Policies for land-use planning

  Management Level:

  - Parts of environmental areas are protected from being used for production
• National & International Agreements- Environmental Law:

  - Laws ban use of wood from non-sustainably managed forests & excessive logging

  - Laws control land e.g. Brazilian Forest Code state landowners must keep 50-80% of their land as forest
• Local Policies- The creation of national parks & forest reserves:

  - Damaging activities can be monitored & prevented

  - Central Amazon Conservation Complex (CACC) set up in Brazil in 2003 protects rainforests & biodiversity whilst allowing people to use forest in a sustainable way

  - E.g. Jan National Park covers 5.6m acres & is a UNESCO site

  - E.g. Para rainforest reserve (15m ha) links to existing reserves to form a large conservation corridor in N Amazon
• Local Policies- Agroforestry:


  - Combining planted trees with crops

  - Trees in agroforestry systems will hold more carbon than crops alone
• Local Policies- Reforestation:


  - Planting trees in an area without trees= atmospheric carbon being sequestrated

  - Have to plant same species of trees (otherwise ecosystem is affected)

  - Sustainable Forest Management: form of sequestration as carbon in wood is made into e.g. furniture so remains out of atmosphere
• Local Policies- Selective Logging:


  - Only some trees are felled (usually oldest)

  - Less damaging than removing all trees in one area

  - Canopy remains & soil is not exposed, allowing forest to regenerate

  - Impact on water & carbon cycle is small